updated top-level README and version_decl for V4.5 (#1847)
[WRF.git] / phys / module_sf_mynn.F
blobfa9853a2637604dabf82a0bfe06be6f0068f8c09
1 !WRF:MODEL_LAYER:PHYSICS
3 MODULE module_sf_mynn
5 !-------------------------------------------------------------------
6 !Modifications implemented by Joseph Olson NOAA/GSL
7 !The following overviews the current state of this scheme::
9 !   BOTH LAND AND WATER:
10 !1) Calculation of stability parameter (z/L) taken from Li et al. (2010 BLM)
11 !   for first iteration of first time step; afterwards, exact calculation
12 !   using a brute force iterative method described in Olson et al. (2021 NOAA
13 !   Tech memorandum). This method replaces the iterative technique used in 
14 !   module_sf_sfclayrev.F (Jimenez et al. 2013) with mods. Either technique
15 !   gives about the same result. The former technique is retained in this
16 !   module (commented out) for potential subsequent benchmarking.
17 !2) Fixed isflux=0 option to turn off scalar fluxes, but keep momentum
18 !   fluxes for idealized studies (credit: Anna Fitch).
19 !3) Kinematic viscosity varies with temperature according to Andreas (1989).
20 !4) Uses the blended Monin-Obukhov flux-profile relationships COARE (Fairall 
21 !   et al 2003) for the unstable regime (a blended mix of Dyer-Hicks 1974 and
22 !   Grachev et al (2000). Uses Cheng and Brutsaert (2005) for stable conditions.
23 !5) The following overviews the namelist variables that control the 
24 !   aerodynamic roughness lengths (over water) and the thermal and moisture
25 !   roughness lengths (defaults are recommended):
27 !   LAND only:
28 !   "iz0tlnd" namelist option is used to select the following options:
29 !   (default) =0: Zilitinkevich (1995); Czil now set to 0.085
30 !             =1: Czil_new (modified according to Chen & Zhang 2008)
31 !             =2: Modified Yang et al (2002, 2008) - generalized for all landuse
32 !             =3: constant zt = z0/7.4 (original form; Garratt 1992)
34 !   WATER only:
35 !   "isftcflx" namelist option is used to select the following options:
36 !   (default) =0: z0, zt, and zq from the COARE algorithm. Set COARE_OPT (below) to
37 !                 3.0 (Fairall et al. 2003, default)
38 !                 3.5 (Edson et al 2013) - now with bug fix (Edson et al. 2014, JPO)
39 !             =1: z0 from Davis et al (2008), zt & zq from COARE 3.0/3.5
40 !             =2: z0 from Davis et al (2008), zt & zq from Garratt (1992)
41 !             =3: z0 from Taylor and Yelland (2004), zt and zq from COARE 3.0/3.5
43 !   SNOW/ICE only:
44 !   Andreas (2002) snow/ice parameterization for thermal and
45 !   moisture roughness is used over all gridpoints with snow deeper than
46 !   0.1 m. This algorithm calculates a z0 for snow (Andreas et al. 2005, BLM), 
47 !   which is only used as part of the thermal and moisture roughness
48 !   length calculation, not to directly impact the surface winds.
50 ! Misc:
51 !1) Added a more elaborate diagnostic for u10 & V10 for high vertical resolution
52 !   model configurations but for most model configurations with depth of
53 !   the lowest half-model level near 10 m, a neutral-log diagnostic is used.
55 !2) Option to activate stochastic parameter perturbations (SPP), which
56 !   perturb z0, zt, and zq, along with many other parameters in the MYNN-
57 !   EDMF scheme. 
59 !NOTE: This code was primarily tested in combination with the RUC LSM.
60 !      Performance with the Noah (or other) LSM is relatively unknown.
61 !-------------------------------------------------------------------
62 !For WRF
63   USE module_model_constants, only: &
64        &p1000mb, ep_2
66 !-------------------------------------------------------------------
67   IMPLICIT NONE
68 !-------------------------------------------------------------------
69 !For non-WRF
70 !   REAL    , PARAMETER :: g            = 9.81
71 !   REAL    , PARAMETER :: r_d          = 287.
72 !   REAL    , PARAMETER :: cp           = 7.*r_d/2.
73 !   REAL    , PARAMETER :: r_v          = 461.6
74 !   REAL    , PARAMETER :: cpv          = 4.*r_v
75 !   REAL    , PARAMETER :: rcp          = r_d/cp
76 !   REAL    , PARAMETER :: XLV          = 2.5E6
77 !   REAL    , PARAMETER :: XLF          = 3.50E5
78 !   REAL    , PARAMETER :: p1000mb      = 100000.
79 !   REAL    , PARAMETER :: EP_2         = r_d/r_v
81   REAL, PARAMETER :: ep_3=1.-ep_2 
82   REAL, PARAMETER :: wmin=0.1    ! Minimum wind speed
83   REAL, PARAMETER :: VCONVC=1.25
84   REAL, PARAMETER :: SNOWZ0=0.011
85   REAL, PARAMETER :: COARE_OPT=3.0  ! 3.0 or 3.5
86   INTEGER, PARAMETER :: psi_opt = 0    ! 0 = stable: Cheng and Brustaert
87                                        !     unstable: blended COARE
88                                        ! 1 = GFS
89   REAL, PARAMETER :: qvmin = 1e-9
90   !For debugging purposes:
91   LOGICAL, PARAMETER :: debug_code = .false.
93   REAL,   DIMENSION(0:1000 ),SAVE :: psim_stab,psim_unstab, &
94                                      psih_stab,psih_unstab
96 CONTAINS
98 !-------------------------------------------------------------------
99   SUBROUTINE mynn_sf_init_driver(allowed_to_read)
101     LOGICAL, INTENT(in) :: allowed_to_read
103     !Fill the PSIM and PSIH tables. This code was leveraged from
104     !module_sf_sfclayrev.F, leveraging the work from Pedro Jimenez.
105     !This subroutine returns a blended form from Dyer and Hicks (1974)
106     !and Grachev et al (2000) for unstable conditions and the form 
107     !from Cheng and Brutsaert (2005) for stable conditions.
109      CALL psi_init(psi_opt)
111   END SUBROUTINE mynn_sf_init_driver
113 !-------------------------------------------------------------------
114    SUBROUTINE SFCLAY_mynn(                                  &
115               U3D,V3D,T3D,QV3D,P3D,dz8w,th3d,rho3d,         &
116               CP,G,ROVCP,R,XLV,PSFCPA,CHS,CHS2,CQS2,CPM,    &
117               ZNT,UST,PBLH,MAVAIL,ZOL,MOL,REGIME,PSIM,PSIH, &
118               XLAND,HFX,QFX,LH,TSK,FLHC,FLQC,QGH,QSFC,RMOL, &
119               U10,V10,TH2,T2,Q2,SNOWH,                      &
120               GZ1OZ0,WSPD,BR,ISFFLX,DX,                     &
121               SVP1,SVP2,SVP3,SVPT0,EP1,EP2,                 &
122               KARMAN,itimestep,ch,qcg,                      &
123               spp_pbl,pattern_spp_pbl,                      &
124               ids,ide, jds,jde, kds,kde,                    &
125               ims,ime, jms,jme, kms,kme,                    &
126               its,ite, jts,jte, kts,kte,                    &
127               ustm,ck,cka,cd,cda,isftcflx,iz0tlnd           )
128 !-------------------------------------------------------------------
129       IMPLICIT NONE
130 !-------------------------------------------------------------------
131 !-- U3D         3D u-velocity interpolated to theta points (m/s)
132 !-- V3D         3D v-velocity interpolated to theta points (m/s)
133 !-- T3D         3D temperature (K)
134 !-- QV3D        3D water vapor mixing ratio (Kg/Kg)
135 !-- P3D         3D pressure (Pa)
136 !-- RHO3D       3D density (kg/m3) 
137 !-- dz8w        3D dz between full levels (m)
138 !-- CP          heat capacity at constant pressure for dry air (J/kg/K)
139 !-- G           acceleration due to gravity (m/s^2)
140 !-- ROVCP       R/CP
141 !-- R           gas constant for dry air (J/kg/K)
142 !-- XLV         latent heat of vaporization for water (J/kg)
143 !-- PSFCPA      surface pressure (Pa)
144 !-- ZNT         roughness length (m)
145 !-- UST         u* in similarity theory (m/s)
146 !-- USTM        u* in similarity theory (m/s) w* added to WSPD. This is
147 !               used to couple with TKE scheme but not in MYNN.
148 !               (as of now, USTM = UST in this version)
149 !-- PBLH        PBL height from previous time (m)
150 !-- MAVAIL      surface moisture availability (between 0 and 1)
151 !-- ZOL         z/L height over Monin-Obukhov length
152 !-- MOL         T* (similarity theory) (K)
153 !-- RMOL        Reciprocal of M-O length (/m)
154 !-- REGIME      flag indicating PBL regime (stable, unstable, etc.)
155 !-- PSIM        similarity stability function for momentum
156 !-- PSIH        similarity stability function for heat
157 !-- XLAND       land mask (1 for land, 2 for water)
158 !-- HFX         upward heat flux at the surface (W/m^2)
159 !-- QFX         upward moisture flux at the surface (kg/m^2/s)
160 !-- LH          net upward latent heat flux at surface (W/m^2)
161 !-- TSK         surface temperature (K)
162 !-- FLHC        exchange coefficient for heat (W/m^2/K)
163 !-- FLQC        exchange coefficient for moisture (kg/m^2/s)
164 !-- CHS         heat/moisture exchange coefficient for LSM (m/s)
165 !-- QGH         lowest-level saturated mixing ratio
166 !-- QSFC        qv (specific humidity) at the surface
167 !-- QSFCMR      qv (mixing ratio) at the surface
168 !-- U10         diagnostic 10m u wind
169 !-- V10         diagnostic 10m v wind
170 !-- TH2         diagnostic 2m theta (K)
171 !-- T2          diagnostic 2m temperature (K)
172 !-- Q2          diagnostic 2m mixing ratio (kg/kg)
173 !-- SNOWH       Snow height (m)
174 !-- GZ1OZ0      log((z1+ZNT)/ZNT) where ZNT is roughness length 
175 !-- WSPD        wind speed at lowest model level (m/s)
176 !-- BR          bulk Richardson number in surface layer
177 !-- ISFFLX      isfflx=1 for surface heat and moisture fluxes
178 !-- DX          horizontal grid size (m)
179 !-- SVP1        constant for saturation vapor pressure (=0.6112 kPa)
180 !-- SVP2        constant for saturation vapor pressure (=17.67 dimensionless)
181 !-- SVP3        constant for saturation vapor pressure (=29.65 K)
182 !-- SVPT0       constant for saturation vapor pressure (=273.15 K)
183 !-- EP1         constant for virtual temperature (Rv/Rd - 1) (dimensionless)
184 !-- EP2         constant for spec. hum. calc (Rd/Rv = 0.622) (dimensionless)
185 !-- EP3         constant for spec. hum. calc (1 - Rd/Rv = 0.378 ) (dimensionless)
186 !-- KARMAN      Von Karman constant
187 !-- ck          enthalpy exchange coeff at 10 meters
188 !-- cd          momentum exchange coeff at 10 meters
189 !-- cka         enthalpy exchange coeff at the lowest model level
190 !-- cda         momentum exchange coeff at the lowest model level
191 !-- isftcflx    =0: z0, zt, and zq from COARE3.0/3.5 (Fairall et al 2003/Edson et al 2013)
192 !   (water      =1: z0 from Davis et al (2008), zt & zq from COARE3.0/3.5
193 !    only)      =2: z0 from Davis et al (2008), zt & zq from Garratt (1992)
194 !               =3: z0 from Taylor and Yelland (2004), zt and zq from COARE 3.0/3.5
195 !-- iz0tlnd     =0: Zilitinkevich (1995) with Czil=0.085, 
196 !   (land       =1: Czil_new (modified according to Chen & Zhang 2008)
197 !    only)      =2: Modified Yang et al (2002, 2008) - generalized for all landuse
198 !               =3: constant zt = z0/7.4 (Garratt 1992)
200 !-- ids         start index for i in domain
201 !-- ide         end index for i in domain
202 !-- jds         start index for j in domain
203 !-- jde         end index for j in domain
204 !-- kds         start index for k in domain
205 !-- kde         end index for k in domain
206 !-- ims         start index for i in memory
207 !-- ime         end index for i in memory
208 !-- jms         start index for j in memory
209 !-- jme         end index for j in memory
210 !-- kms         start index for k in memory
211 !-- kme         end index for k in memory
212 !-- its         start index for i in tile
213 !-- ite         end index for i in tile
214 !-- jts         start index for j in tile
215 !-- jte         end index for j in tile
216 !-- kts         start index for k in tile
217 !-- kte         end index for k in tile
218 !=================================================================
219 ! SCALARS
220 !===================================
221       INTEGER,  INTENT(IN)   ::        ids,ide, jds,jde, kds,kde, &
222                                        ims,ime, jms,jme, kms,kme, &
223                                        its,ite, jts,jte, kts,kte
224       INTEGER,  INTENT(IN)   ::        itimestep
225       REAL,     INTENT(IN)   ::        SVP1,SVP2,SVP3,SVPT0
226       REAL,     INTENT(IN)   ::        EP1,EP2,KARMAN
227       REAL,     INTENT(IN)   ::        CP,G,ROVCP,R,XLV,DX
228 !NAMELIST OPTIONS:
229       INTEGER,  INTENT(IN)   ::        ISFFLX
230       INTEGER,  OPTIONAL,  INTENT(IN)   ::     ISFTCFLX, IZ0TLND
231       INTEGER,  OPTIONAL,  INTENT(IN)   ::     spp_pbl
233 !===================================
234 ! 3D VARIABLES
235 !===================================
236       REAL,     DIMENSION( ims:ime, kms:kme, jms:jme )           , &
237                 INTENT(IN   )   ::                           dz8w, &
238                                                              QV3D, &
239                                                               P3D, &
240                                                               T3D, &
241                                                           U3D,V3D, &
242                                                        RHO3D,th3d
244       REAL, DIMENSION( ims:ime, kms:kme, jms:jme ), OPTIONAL,      &
245                 INTENT(IN) ::                      pattern_spp_pbl
246 !===================================
247 ! 2D VARIABLES
248 !===================================
249       REAL,     DIMENSION( ims:ime, jms:jme )                    , &
250                 INTENT(IN   )               ::             MAVAIL, &
251                                                              PBLH, &
252                                                             XLAND, &
253                                                               TSK, &
254                                                               QCG, &
255                                                            PSFCPA ,&
256                                                             SNOWH
259       REAL,     DIMENSION( ims:ime, jms:jme )                    , &
260                 INTENT(OUT  )               ::            U10,V10, &
261                                                         TH2,T2,Q2
263       REAL, OPTIONAL, DIMENSION( ims:ime, jms:jme )              , &
264                 INTENT(OUT)     ::              ck,cka,cd,cda,ustm
266       REAL,     DIMENSION( ims:ime, jms:jme )                    , &
267                 INTENT(INOUT)               ::             REGIME, &
268                                                               HFX, &
269                                                               QFX, &
270                                                                LH, &
271                                                          MOL,RMOL, &
272                                                         QSFC, QGH, &
273                                                               ZNT, &
274                                                               ZOL, &
275                                                               UST, &
276                                                               CPM, &
277                                                              CHS2, &
278                                                              CQS2, &
279                                                               CHS, &
280                                                                CH, &
281                                                         FLHC,FLQC, &
282                                                    GZ1OZ0,WSPD,BR, &
283                                                         PSIM,PSIH
285 !ADDITIONAL OUTPUT
286       REAL,     DIMENSION( ims:ime, jms:jme )    ::   wstar,qstar
287 !===================================
288 ! 1D LOCAL ARRAYS
289 !===================================
290       REAL,     DIMENSION( its:ite ) ::                       U1D, &
291                                                               V1D, &
292                                                         U1D2,V1D2, & !level2 winds
293                                                              QV1D, &
294                                                               P1D, &
295                                                               T1D, &
296                                                             RHO1D, &
297                                                            dz8w1d, & !level 1 height
298                                                            dz2w1d    !level 2 height
301       REAL,     DIMENSION( its:ite ) ::                  rstoch1D
303       INTEGER ::  I,J,K,itf,jtf,ktf
304 !-----------------------------------------------------------
306       itf=MIN0(ite,ide-1)
307       jtf=MIN0(jte,jde-1)
308       ktf=MIN0(kte,kde-1)
310       DO J=jts,jte
311         DO i=its,ite
312            dz8w1d(I) = dz8w(i,kts,j)
313            dz2w1d(I) = dz8w(i,kts+1,j)
314            U1D(i) =U3D(i,kts,j)
315            V1D(i) =V3D(i,kts,j)
316            !2nd model level winds - for diags with high-res grids
317            U1D2(i) =U3D(i,kts+1,j)
318            V1D2(i) =V3D(i,kts+1,j)
319            QV1D(i)=QV3D(i,kts,j)
320            P1D(i) =P3D(i,kts,j)
321            T1D(i) =T3D(i,kts,j)
322            RHO1D(i)=RHO3D(i,kts,j)
323            if (spp_pbl==1) then
324                rstoch1D(i)=pattern_spp_pbl(i,kts,j)
325            else
326                rstoch1D(i)=0.0
327            endif
328         ENDDO
330         IF (itimestep==1) THEN
331            DO i=its,ite
332               UST(i,j)=MAX(0.04*SQRT(U1D(i)*U1D(i) + V1D(i)*V1D(i)),0.001)
333               MOL(i,j)=0.     ! Tstar
334               QSFC(i,j)=QV3D(i,kts,j)/(1.+QV3D(i,kts,j))
335               qstar(i,j)=0.0
336            ENDDO
337         ENDIF
339         CALL SFCLAY1D_mynn(                                        &
340                 J,U1D,V1D,T1D,QV1D,P1D,dz8w1d,rho1d,               &
341                 U1D2,V1D2,dz2w1d,                                  &
342                 CP,G,ROVCP,R,XLV,PSFCPA(ims,j),CHS(ims,j),CHS2(ims,j),&
343                 CQS2(ims,j),CPM(ims,j),PBLH(ims,j), RMOL(ims,j),   &
344                 ZNT(ims,j),UST(ims,j),MAVAIL(ims,j),ZOL(ims,j),    &
345                 MOL(ims,j),REGIME(ims,j),PSIM(ims,j),PSIH(ims,j),  &
346                 XLAND(ims,j),HFX(ims,j),QFX(ims,j),TSK(ims,j),     &
347                 U10(ims,j),V10(ims,j),TH2(ims,j),T2(ims,j),        &
348                 Q2(ims,j),FLHC(ims,j),FLQC(ims,j),SNOWH(ims,j),    &
349                 QGH(ims,j),QSFC(ims,j),LH(ims,j),                  &
350                 GZ1OZ0(ims,j),WSPD(ims,j),BR(ims,j),ISFFLX,DX,     &
351                 SVP1,SVP2,SVP3,SVPT0,EP1,EP2,KARMAN,               &
352                 ch(ims,j),qcg(ims,j),                              &
353                 itimestep,                                         &
354 !JOE-begin additional output
355                 wstar(ims,j),qstar(ims,j),                         &
356 !JOE-end
357                 spp_pbl,rstoch1D,                                  &
358                 ids,ide, jds,jde, kds,kde,                         &
359                 ims,ime, jms,jme, kms,kme,                         &
360                 its,ite, jts,jte, kts,kte,                         &
361                 isftcflx, iz0tlnd,                                 &
362                 USTM(ims,j),CK(ims,j),CKA(ims,j),                  &
363                 CD(ims,j),CDA(ims,j)                               &
364                                                                    )
365       ENDDO
367     END SUBROUTINE SFCLAY_MYNN
369 !-------------------------------------------------------------------
370    SUBROUTINE SFCLAY1D_mynn(                                       &
371                      J,U1D,V1D,T1D,QV1D,P1D,dz8w1d,rho1d,          &
372                      U1D2,V1D2,dz2w1d,                             &
373                      CP,G,ROVCP,R,XLV,PSFCPA,CHS,CHS2,CQS2,CPM,    &
374                      PBLH,RMOL,ZNT,UST,MAVAIL,ZOL,MOL,REGIME,      &
375                      PSIM,PSIH,XLAND,HFX,QFX,TSK,                  &
376                      U10,V10,TH2,T2,Q2,FLHC,FLQC,SNOWH,QGH,        &
377                      QSFC,LH,GZ1OZ0,WSPD,BR,ISFFLX,DX,             &
378                      SVP1,SVP2,SVP3,SVPT0,EP1,EP2,                 &
379                      KARMAN,ch,qcg,                                &
380                      itimestep,                                    &
381 !JOE-additional output
382                      wstar,qstar,                                  &
383 !JOE-end
384                      spp_pbl,rstoch1D,                             &
385                      ids,ide, jds,jde, kds,kde,                    &
386                      ims,ime, jms,jme, kms,kme,                    &
387                      its,ite, jts,jte, kts,kte,                    &
388                      isftcflx, iz0tlnd,                            &
389                      ustm,ck,cka,cd,cda                            &
390                      )
392 !-------------------------------------------------------------------
393       IMPLICIT NONE
394 !-------------------------------------------------------------------
395 ! SCALARS
396 !-----------------------------
397       INTEGER,  INTENT(IN) ::        ids,ide, jds,jde, kds,kde, &
398                                      ims,ime, jms,jme, kms,kme, &
399                                      its,ite, jts,jte, kts,kte, &
400                                      J, itimestep
402       REAL,     PARAMETER  :: XKA=2.4E-5   !molecular diffusivity
403       REAL,     PARAMETER  :: PRT=1.       !prandlt number
404       REAL,     INTENT(IN) :: SVP1,SVP2,SVP3,SVPT0,EP1,EP2
405       REAL,     INTENT(IN) :: KARMAN,CP,G,ROVCP,R,XLV,DX
407 !-----------------------------
408 ! NAMELIST OPTIONS
409 !-----------------------------
410       INTEGER,  INTENT(IN) :: ISFFLX
411       INTEGER,  OPTIONAL,  INTENT(IN )   ::     ISFTCFLX, IZ0TLND
412       INTEGER,    INTENT(IN)             ::     spp_pbl
414 !-----------------------------
415 ! 1D ARRAYS
416 !-----------------------------
417       REAL,     DIMENSION( ims:ime ), INTENT(IN)    ::     MAVAIL, &
418                                                              PBLH, &
419                                                             XLAND, &
420                                                               TSK, &
421                                                            PSFCPA, &
422                                                               QCG, &
423                                                             SNOWH
425       REAL,     DIMENSION( its:ite ), INTENT(IN)   ::     U1D,V1D, &
426                                                         U1D2,V1D2, &
427                                                          QV1D,P1D, &
428                                                               T1D, &
429                                                     dz8w1d,dz2w1d, &
430                                                             RHO1D
432       REAL,     DIMENSION( ims:ime ), INTENT(INOUT) ::     REGIME, &
433                                                        HFX,QFX,LH, &
434                                                          MOL,RMOL, &
435                                                          QGH,QSFC, &
436                                                               ZNT, &
437                                                               ZOL, &
438                                                               UST, &
439                                                               CPM, &
440                                                         CHS2,CQS2, &
441                                                            CHS,CH, &
442                                                         FLHC,FLQC, &
443                                                            GZ1OZ0, &
444                                                              WSPD, &
445                                                                BR, &
446                                                         PSIM,PSIH
447       REAL,     DIMENSION( its:ite ), INTENT(IN)   ::     rstoch1D
449       ! DIAGNOSTIC OUTPUT
450       REAL,     DIMENSION( ims:ime ), INTENT(OUT)   ::    U10,V10, &
451                                                         TH2,T2,Q2
453       REAL, OPTIONAL, DIMENSION( ims:ime )                       , &
454                 INTENT(OUT)     ::              ck,cka,cd,cda,ustm
455 !--------------------------------------------
456 !JOE-additinal output
457       REAL,     DIMENSION( ims:ime ) ::                wstar,qstar
458 !JOE-end
459 !----------------------------------------------------------------
460 ! LOCAL VARS
461 !----------------------------------------------------------------
462       REAL, DIMENSION(its:ite) :: &
463                  ZA, &    !Height of lowest 1/2 sigma level(m)
464                 ZA2, &    !Height of 2nd lowest 1/2 sigma level(m)
465               THV1D, &    !Theta-v at lowest 1/2 sigma (K)
466                TH1D, &    !Theta at lowest 1/2 sigma (K)
467                TC1D, &    !T at lowest 1/2 sigma (Celsius)
468                TV1D, &    !Tv at lowest 1/2 sigma (K)
469                QVSH, &    !qv at lowest 1/2 sigma (spec humidity)
470               PSIH2, &    !M-O stability functions at z=2 m
471              PSIM10, &    !M-O stability functions at z=10 m
472              PSIH10, &    !M-O stability functions at z=10 m
473               WSPDI, & 
474             z_t,z_q, &    !thermal & moisture roughness lengths
475            ZNTstoch, &
476              GOVRTH, &    !g/theta
477                THGB, &    !theta at ground
478               THVGB, &    !theta-v at ground
479                PSFC, &    !press at surface (Pa/1000)
480              QSFCMR, &    !qv at surface (mixing ratio, kg/kg)
481              GZ2OZ0, &    !LOG((2.0+ZNT(I))/ZNT(I))
482             GZ10OZ0, &    !LOG((10.+ZNT(I))/ZNT(I))
483              GZ2OZt, &    !LOG((2.0+z_t(i))/z_t(i))
484             GZ10OZt, &    !LOG((10.+z_t(i))/z_t(i))
485              GZ1OZt, &    !LOG((ZA(I)+z_t(i))/z_t(i))
486              zratio       !z0/zt
488       INTEGER ::  N,I,K,L,yesno
490       REAL    ::  PL,THCON,TVCON,E1
491       REAL    ::  DTHVDZ,DTHVM,VCONV,ZOL2,ZOL10,ZOLZA,ZOLZ0,ZOLZT
492       REAL    ::  DTG,PSIX,DTTHX,DTHDZ,PSIX10,PSIT,PSIT2, &
493                   PSIQ,PSIQ2,PSIQ10,DZDT
494       REAL    ::  FLUXC,VSGD
495       REAL    ::  restar,VISC,DQG,OLDUST,OLDTST
497 !-------------------------------------------------------------------
499       DO I=its,ite
500          ! CONVERT GROUND & LOWEST LAYER TEMPERATURE TO POTENTIAL TEMPERATURE:
501          ! PSFC cmb
502          PSFC(I)=PSFCPA(I)/1000.
503          THGB(I)=TSK(I)*(100./PSFC(I))**ROVCP   !(K)              
504          ! PL cmb
505          PL=P1D(I)/1000.                                                   
506          THCON=(100./PL)**ROVCP                                                 
507          TH1D(I)=T1D(I)*THCON                   !(Theta, K)
508          TC1D(I)=T1D(I)-273.15                  !(T, Celsius)    
510          ! CONVERT TO VIRTUAL TEMPERATURE
511          QVSH(I)=QV1D(I)/(1.+QV1D(I))        !CONVERT TO SPEC HUM (kg/kg)
512          TVCON=(1.+EP1*QVSH(I))
513          THV1D(I)=TH1D(I)*TVCON                 !(K)
514          TV1D(I)=T1D(I)*TVCON   !(K)
516          !RHO1D(I)=PSFCPA(I)/(R*TV1D(I)) !now using value calculated in sfc driver
517          ZA(I)=0.5*dz8w1d(I)             !height of first half-sigma level 
518          ZA2(I)=dz8w1d(I) + 0.5*dz2w1d(I)    !height of 2nd half-sigma level
519          GOVRTH(I)=G/TH1D(I)
520       ENDDO
522       DO I=its,ite
523          IF (TSK(I) .LT. 273.15) THEN
524             !SATURATION VAPOR PRESSURE WRT ICE (SVP1=.6112; 10*mb)
525             E1=SVP1*EXP(4648*(1./273.15 - 1./TSK(I)) - &
526             & 11.64*LOG(273.15/TSK(I)) + 0.02265*(273.15 - TSK(I)))
527          ELSE
528             !SATURATION VAPOR PRESSURE WRT WATER (Bolton 1980)
529             E1=SVP1*EXP(SVP2*(TSK(I)-SVPT0)/(TSK(I)-SVP3))
530          ENDIF
531          !FOR LAND POINTS, QSFC can come from LSM, ONLY RECOMPUTE OVER WATER
532          IF (xland(i).gt.1.5 .or. QSFC(i).le.0.0) THEN   !WATER
533             QSFC(I)=EP2*E1/(PSFC(I)-ep_3*E1)             !specific humidity    
534             QSFCMR(I)=EP2*E1/(PSFC(I)-E1)                !mixing ratio 
535          ELSE                                            !LAND 
536             QSFCMR(I)=QSFC(I)/(1.-QSFC(I))
537          ENDIF
539          ! QGH CHANGED TO USE LOWEST-LEVEL AIR TEMP CONSISTENT WITH MYJSFC CHANGE
540          ! Q2SAT = QGH IN LSM
541          IF (TSK(I) .LT. 273.15) THEN
542             !SATURATION VAPOR PRESSURE WRT ICE
543             E1=SVP1*EXP(4648*(1./273.15 - 1./T1D(I)) - &
544             &  11.64*LOG(273.15/T1D(I)) + 0.02265*(273.15 - T1D(I)))
545          ELSE
546             !SATURATION VAPOR PRESSURE WRT WATER (Bolton 1980)
547             E1=SVP1*EXP(SVP2*(T1D(I)-SVPT0)/(T1D(I)-SVP3))
548          ENDIF
549          PL=P1D(I)/1000.
550          !QGH(I)=EP2*E1/(PL-ep_3*E1)    !specific humidity
551          QGH(I)=EP2*E1/(PL-E1)          !mixing ratio
552          CPM(I)=CP*(1.+0.84*QV1D(I))
553       ENDDO
555       DO I=its,ite
556          WSPD(I)=SQRT(U1D(I)*U1D(I)+V1D(I)*V1D(I))     
558          !TGS:THVGB(I)=THGB(I)*(1.+EP1*QSFC(I)*MAVAIL(I)) 
559          THVGB(I)=THGB(I)*(1.+EP1*QSFC(I))
561          DTHDZ=(TH1D(I)-THGB(I))
562          DTHVDZ=(THV1D(I)-THVGB(I))
564          !--------------------------------------------------------
565          !  Calculate the convective velocity scale (WSTAR) and 
566          !  subgrid-scale velocity (VSGD) following Beljaars (1995, QJRMS) 
567          !  and Mahrt and Sun (1995, MWR), respectively
568          !-------------------------------------------------------
569          !  Use Beljaars over land and water
570          fluxc = max(hfx(i)/RHO1D(i)/cp                    &
571          &    + ep1*THVGB(I)*qfx(i)/RHO1D(i),0.)
572          !WSTAR(I) = vconvc*(g/TSK(i)*pblh(i)*fluxc)**.33
573          IF (xland(i).gt.1.5 .or. QSFC(i).le.0.0) THEN   !WATER
574             WSTAR(I) = vconvc*(g/TSK(i)*pblh(i)*fluxc)**.33
575          ELSE                                            !LAND
576             !increase height scale, assuming that the non-local transoport
577             !from the mass-flux (plume) mixing exceedsd the PBLH.
578             WSTAR(I) = vconvc*(g/TSK(i)*MIN(1.5*pblh(i),4000.)*fluxc)**.33
579          ENDIF
580          !--------------------------------------------------------
581          ! Mahrt and Sun low-res correction
582          ! (for 13 km ~ 0.37 m/s; for 3 km == 0 m/s)
583          !--------------------------------------------------------
584          VSGD = 0.32 * (max(dx/5000.-1.,0.))**.33
585          WSPD(I)=SQRT(WSPD(I)*WSPD(I)+WSTAR(I)*WSTAR(I)+vsgd*vsgd)
586          WSPD(I)=MAX(WSPD(I),wmin)
588          !--------------------------------------------------------
589          ! CALCULATE THE BULK RICHARDSON NUMBER OF SURFACE LAYER, 
590          ! ACCORDING TO AKB(1976), EQ(12). 
591          !--------------------------------------------------------
592          BR(I)=GOVRTH(I)*ZA(I)*DTHVDZ/(WSPD(I)*WSPD(I))
593          IF (ITIMESTEP == 1) THEN
594             !SET LIMITS ACCORDING TO Li et al. (2010) Boundary-Layer Meteorol (p.158)
595             BR(I)=MAX(BR(I),-2.0)
596             BR(I)=MIN(BR(I),2.0)
597          ELSE
598             BR(I)=MAX(BR(I),-4.0)
599             BR(I)=MIN(BR(I), 4.0)
600          ENDIF
602          ! IF PREVIOUSLY UNSTABLE, DO NOT LET INTO REGIMES 1 AND 2 (STABLE)
603          !if (itimestep .GT. 1) THEN
604          !    IF(MOL(I).LT.0.)BR(I)=MIN(BR(I),0.0)
605          !ENDIF
606      
607       ENDDO
609  1006   format(A,F7.3,A,f9.4,A,f9.5,A,f9.4)
610  1007   format(A,F2.0,A,f6.2,A,f7.3,A,f7.2)
612 !--------------------------------------------------------------------      
613 !--------------------------------------------------------------------      
614 !--- BEGIN I-LOOP
615 !--------------------------------------------------------------------
616 !--------------------------------------------------------------------
618  DO I=its,ite
620     !COMPUTE KINEMATIC VISCOSITY (m2/s) Andreas (1989) CRREL Rep. 89-11
621     !valid between -173 and 277 degrees C.
622     VISC=1.326e-5*(1. + 6.542e-3*TC1D(I) + 8.301e-6*TC1D(I)*TC1D(I) &
623                       - 4.84e-9*TC1D(I)*TC1D(I)*TC1D(I))
625     IF ((XLAND(I)-1.5).GE.0) THEN
626        !--------------------------------------
627        ! WATER
628        !--------------------------------------
629        ! CALCULATE z0 (znt)
630        !--------------------------------------
631        IF ( PRESENT(ISFTCFLX) ) THEN
632           IF ( ISFTCFLX .EQ. 0 ) THEN
633              IF (COARE_OPT .EQ. 3.0) THEN
634                 !COARE 3.0 (MISLEADING SUBROUTINE NAME)
635                 CALL charnock_1955(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
636              ELSE
637                 !COARE 3.5
638                 CALL edson_etal_2013(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
639              ENDIF
640           ELSEIF ( ISFTCFLX .EQ. 1 .OR. ISFTCFLX .EQ. 2 ) THEN
641              CALL davis_etal_2008(ZNT(i),UST(i))
642           ELSEIF ( ISFTCFLX .EQ. 3 ) THEN
643              CALL Taylor_Yelland_2001(ZNT(i),UST(i),WSPD(i))
644           ELSEIF ( ISFTCFLX .EQ. 4 ) THEN
645              IF (COARE_OPT .EQ. 3.0) THEN
646                 !COARE 3.0 (MISLEADING SUBROUTINE NAME)
647                 CALL charnock_1955(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
648              ELSE
649                 !COARE 3.5
650                 CALL edson_etal_2013(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
651              ENDIF
652           ENDIF
653        ELSE
654           !DEFAULT TO COARE 3.0/3.5
655           IF (COARE_OPT .EQ. 3.0) THEN
656              !COARE 3.0
657              CALL charnock_1955(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
658           ELSE
659              !COARE 3.5
660              CALL edson_etal_2013(ZNT(i),UST(i),WSPD(i),visc,ZA(I))
661           ENDIF
662        ENDIF
664        ! add stochastic perturbaction of ZNT
665        if (spp_pbl==1) then
666           ZNTstoch(I)  = MAX(ZNT(I) + ZNT(I)*1.0*rstoch1D(i), 1e-6)
667        else
668           ZNTstoch(I)  = ZNT(I)
669        endif
671        !COMPUTE ROUGHNESS REYNOLDS NUMBER (restar) USING NEW ZNT
672        ! AHW: Garrattt formula: Calculate roughness Reynolds number
673        !      Kinematic viscosity of air (linear approx to
674        !      temp dependence at sea level)
675        restar=MAX(ust(i)*ZNTstoch(i)/visc, 0.1)
677        !--------------------------------------
678        !CALCULATE z_t and z_q
679        !--------------------------------------
680        IF ( PRESENT(ISFTCFLX) ) THEN
681           IF ( ISFTCFLX .EQ. 0 ) THEN
682              IF (COARE_OPT .EQ. 3.0) THEN
683                 CALL fairall_etal_2003(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
684              ELSE
685                 !presumably, this will be published soon, but hasn't yet
686                 CALL fairall_etal_2014(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
687              ENDIF
688           ELSEIF ( ISFTCFLX .EQ. 1 ) THEN
689              IF (COARE_OPT .EQ. 3.0) THEN
690                 CALL fairall_etal_2003(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
691              ELSE
692                 CALL fairall_etal_2014(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
693              ENDIF
694           ELSEIF ( ISFTCFLX .EQ. 2 ) THEN
695              CALL garratt_1992(z_t(i),z_q(i),ZNTstoch(i),restar,XLAND(I))
696           ELSEIF ( ISFTCFLX .EQ. 3 ) THEN
697              IF (COARE_OPT .EQ. 3.0) THEN
698                 CALL fairall_etal_2003(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
699              ELSE
700                 CALL fairall_etal_2014(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
701              ENDIF
702           ENDIF
703        ELSE
704           !DEFAULT TO COARE 3.0/3.5
705           IF (COARE_OPT .EQ. 3.0) THEN
706              CALL fairall_etal_2003(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
707           ELSE
708              CALL fairall_etal_2014(z_t(i),z_q(i),restar,UST(i),visc,rstoch1D(i),spp_pbl)
709           ENDIF
710        ENDIF
712     ELSE
714        ! add stochastic perturbaction of ZNT
715        if (spp_pbl==1) then
716           ZNTstoch(I)  = MAX(ZNT(I) + ZNT(I)*1.0*rstoch1D(i), 1e-6)
717        else
718           ZNTstoch(I)  = ZNT(I)
719        endif
721        !--------------------------------------
722        ! LAND
723        !--------------------------------------
724        !COMPUTE ROUGHNESS REYNOLDS NUMBER (restar) USING DEFAULT ZNT
725        restar=MAX(ust(i)*ZNTstoch(i)/visc, 0.1)
727        !--------------------------------------
728        !GET z_t and z_q
729        !--------------------------------------
730        !CHECK FOR SNOW/ICE POINTS OVER LAND
731        IF ( SNOWH(i) .GE. 0.1) THEN
732           CALL Andreas_2002(ZNTSTOCH(i),visc,ust(i),z_t(i),z_q(i))
733        ELSE
734           IF ( PRESENT(IZ0TLND) ) THEN
735              IF ( IZ0TLND .LE. 1 ) THEN
736                 CALL zilitinkevich_1995(ZNTSTOCH(i),z_t(i),z_q(i),restar,&
737                            UST(I),KARMAN,XLAND(I),IZ0TLND,spp_pbl,rstoch1D(i))
738              ELSEIF ( IZ0TLND .EQ. 2 ) THEN
739                 CALL Yang_2008(ZNTSTOCH(i),z_t(i),z_q(i),UST(i),MOL(I),&
740                                qstar(I),restar,visc,XLAND(I))
741              ELSEIF ( IZ0TLND .EQ. 3 ) THEN
742                 !Original MYNN in WRF-ARW used this form:
743                 CALL garratt_1992(z_t(i),z_q(i),ZNTSTOCH(i),restar,XLAND(I))
744              ENDIF
745           ELSE
746              !DEFAULT TO ZILITINKEVICH
747              CALL zilitinkevich_1995(ZNTSTOCH(i),z_t(i),z_q(i),restar,&
748                            UST(I),KARMAN,XLAND(I),0,spp_pbl,rstoch1D(i))
749           ENDIF
750        ENDIF
752     ENDIF
753     zratio(i)=ZNTstoch(I)/z_t(I)   !needed for Li et al.
755     GZ1OZ0(I)= LOG((ZA(I)+ZNTstoch(I))/ZNTstoch(I))
756     GZ1OZt(I)= LOG((ZA(I)+ZNTstoch(I))/z_t(i))
757     GZ2OZ0(I)= LOG((2.0+ZNTstoch(I))/ZNTstoch(I))                                        
758     GZ2OZt(I)= LOG((2.0+ZNTstoch(I))/z_t(i))
759     GZ10OZ0(I)=LOG((10.+ZNTstoch(I))/ZNTstoch(I)) 
760     GZ10OZt(I)=LOG((10.+ZNTstoch(I))/z_t(i))
762     !--------------------------------------------------------------------      
763     !--- DIAGNOSE BASIC PARAMETERS FOR THE APPROPRIATE STABILITY CLASS:
764     !                                                                                
765     !    THE STABILITY CLASSES ARE DETERMINED BY BR (BULK RICHARDSON NO.).
766     !                                                                                
767     !    CRITERIA FOR THE CLASSES ARE AS FOLLOWS:                                   
768     !                                                                                
769     !        1. BR .GE. 0.2;                                                         
770     !               REPRESENTS NIGHTTIME STABLE CONDITIONS (REGIME=1),               
771     !                                                                                
772     !        2. BR .LT. 0.2 .AND. BR .GT. 0.0;                                       
773     !               REPRESENTS DAMPED MECHANICAL TURBULENT CONDITIONS                
774     !               (REGIME=2),                                                      
775     !                                                                                
776     !        3. BR .EQ. 0.0                                                          
777     !               REPRESENTS FORCED CONVECTION CONDITIONS (REGIME=3),              
778     !                                                                                
779     !        4. BR .LT. 0.0                                                          
780     !               REPRESENTS FREE CONVECTION CONDITIONS (REGIME=4).                
781     !                                                                                
782     !--------------------------------------------------------------------
783     IF (BR(I) .GT. 0.0) THEN
784        IF (BR(I) .GT. 0.2) THEN        
785           !---CLASS 1; STABLE (NIGHTTIME) CONDITIONS:                                    
786           REGIME(I)=1.
787        ELSE
788           !---CLASS 2; DAMPED MECHANICAL TURBULENCE:
789           REGIME(I)=2.
790        ENDIF
792        !COMPUTE z/L first guess:
793        IF (itimestep .LE. 1) THEN
794           CALL Li_etal_2010(ZOL(I),BR(I),ZA(I)/ZNTstoch(I),zratio(I))
795        ELSE
796           ZOL(I)=ZA(I)*KARMAN*G*MOL(I)/(TH1D(I)*MAX(UST(I)*UST(I),0.0001))
797           ZOL(I)=MAX(ZOL(I),0.0)
798           ZOL(I)=MIN(ZOL(I),20.)
799        ENDIF
801        !Use Pedros iterative function to find z/L
802        !zol(I)=zolri(br(I),ZA(I),ZNTstoch(I),z_t(I),ZOL(I),psi_opt)
803        !Use brute-force method
804        zol(I)=zolrib(br(I),ZA(I),ZNTstoch(I),z_t(I),GZ1OZ0(I),GZ1OZt(I),ZOL(I),psi_opt)
805        ZOL(I)=MAX(ZOL(I),0.0)
806        ZOL(I)=MIN(ZOL(I),20.)
808        zolzt = zol(I)*z_t(I)/ZA(I)               ! zt/L
809        zolz0 = zol(I)*ZNTstoch(I)/ZA(I)          ! z0/L
810        zolza = zol(I)*(za(I)+ZNTstoch(I))/za(I)  ! (z+z0/L
811        zol10 = zol(I)*(10.+ZNTstoch(I))/za(I)    ! (10+z0)/L
812        zol2  = zol(I)*(2.+ZNTstoch(I))/za(I)     ! (2+z0)/L 
814        !COMPUTE PSIM and PSIH
815        IF ((XLAND(I)-1.5).GE.0) THEN                                            
816           ! WATER
817           !CALL PSI_Suselj_Sood_2010(PSIM(I),PSIH(I),ZOL(I))
818           !CALL PSI_Beljaars_Holtslag_1991(PSIM(I),PSIH(I),ZOL(I))
819           !CALL PSI_Businger_1971(PSIM(I),PSIH(I),ZOL(I))
820           !CALL PSI_DyerHicks(PSIM(I),PSIH(I),ZOL(I),z_t(I),ZNTstoch(I),ZA(I))
821           !CALL PSI_CB2005(PSIM(I),PSIH(I),zolza,zolz0)
822           ! or use tables
823           psim(I)=psim_stable(zolza,psi_opt)-psim_stable(zolz0,psi_opt)
824           psih(I)=psih_stable(zolza,psi_opt)-psih_stable(zolzt,psi_opt)
825           psim10(I)=psim_stable(zol10,psi_opt)-psim_stable(zolz0,psi_opt)
826           psih10(I)=psih_stable(zol10,psi_opt)-psih_stable(zolz0,psi_opt)
827           psih2(I)=psih_stable(zol2,psi_opt)-psih_stable(zolz0,psi_opt)
828        ELSE
829           ! LAND  
830           !CALL PSI_Beljaars_Holtslag_1991(PSIM(I),PSIH(I),ZOL(I))
831           !CALL PSI_Businger_1971(PSIM(I),PSIH(I),ZOL(I))
832           !CALL PSI_Zilitinkevich_Esau_2007(PSIM(I),PSIH(I),ZOL(I))
833           !CALL PSI_DyerHicks(PSIM(I),PSIH(I),ZOL(I),z_t(I),ZNTstoch(I),ZA(I))
834           !CALL PSI_CB2005(PSIM(I),PSIH(I),zolza,zolz0)
835           ! or use tables
836           psim(I)=psim_stable(zolza,psi_opt)-psim_stable(zolz0,psi_opt)
837           psih(I)=psih_stable(zolza,psi_opt)-psih_stable(zolzt,psi_opt)
838           psim10(I)=psim_stable(zol10,psi_opt)-psim_stable(zolz0,psi_opt)
839           psih10(I)=psih_stable(zol10,psi_opt)-psih_stable(zolz0,psi_opt)
840           psih2(I)=psih_stable(zol2,psi_opt)-psih_stable(zolz0,psi_opt)
841        ENDIF
843        !PSIM10(I)=10./ZA(I)*PSIM(I)
844        !PSIH10(I)=10./ZA(I)*PSIH(I)
845        !PSIM2(I)=2./ZA(I)*PSIM(I)
846        !PSIH2(I)=2./ZA(I)*PSIH(I)
848        ! 1.0 over Monin-Obukhov length
849        RMOL(I)= ZOL(I)/ZA(I)
851     ELSEIF(BR(I) .EQ. 0.) THEN                  
852        !=========================================================  
853        !-----CLASS 3; FORCED CONVECTION/NEUTRAL:                                                
854        !=========================================================
855        REGIME(I)=3.
857        PSIM(I)=0.0
858        PSIH(I)=PSIM(I)
859        PSIM10(I)=0.
860        PSIH10(I)=0.
861        PSIH2(I)=0.
863        ZOL(I)=0.
864        !IF (UST(I) .LT. 0.01) THEN
865        !   ZOL(I)=BR(I)*GZ1OZ0(I)
866        !ELSE
867        !   ZOL(I)=KARMAN*GOVRTH(I)*ZA(I)*MOL(I)/(MAX(UST(I)*UST(I),0.001))
868        !ENDIF
869        RMOL(I) = ZOL(I)/ZA(I)
871     ELSEIF(BR(I) .LT. 0.)THEN
872        !==========================================================
873        !-----CLASS 4; FREE CONVECTION:                                                  
874        !==========================================================
875        REGIME(I)=4.
877        !COMPUTE z/L first guess:
878        IF (itimestep .LE. 1) THEN
879           CALL Li_etal_2010(ZOL(I),BR(I),ZA(I)/ZNTstoch(I),zratio(I))
880        ELSE
881           ZOL(I)=ZA(I)*KARMAN*G*MOL(I)/(TH1D(I)*MAX(UST(I)*UST(I),0.001))
882           ZOL(I)=MAX(ZOL(I),-20.0)
883           ZOL(I)=MIN(ZOL(I),0.0)
884        ENDIF
886        !Use Pedros iterative function to find z/L
887        !zol(I)=zolri(br(I),ZA(I),ZNTstoch(I),z_t(I),ZOL(I),psi_opt)
888        !Use alternative method
889        zol(I)=zolrib(br(I),ZA(I),ZNTstoch(I),z_t(I),GZ1OZ0(I),GZ1OZt(I),ZOL(I),psi_opt)
890        ZOL(I)=MAX(ZOL(I),-20.0)
891        ZOL(I)=MIN(ZOL(I),0.0)
893        zolzt = zol(I)*z_t(I)/ZA(I)                ! zt/L
894        zolz0 = zol(I)*ZNTstoch(I)/ZA(I)           ! z0/L
895        zolza = zol(I)*(za(I)+ZNTstoch(I))/za(I)   ! (z+z0/L
896        zol10 = zol(I)*(10.+ZNTstoch(I))/za(I)     ! (10+z0)/L
897        zol2  = zol(I)*(2.+ZNTstoch(I))/za(I)      ! (2+z0)/L
899        !COMPUTE PSIM and PSIH
900        IF ((XLAND(I)-1.5).GE.0) THEN                                            
901           ! WATER
902           !CALL PSI_Suselj_Sood_2010(PSIM(I),PSIH(I),ZOL(I))
903           !CALL PSI_Hogstrom_1996(PSIM(I),PSIH(I),ZOL(I), z_t(I), ZNTstoch(I), ZA(I))
904           !CALL PSI_Businger_1971(PSIM(I),PSIH(I),ZOL(I))
905           !CALL PSI_DyerHicks(PSIM(I),PSIH(I),ZOL(I),z_t(I),ZNTstoch(I),ZA(I))
906           ! use tables
907           psim(I)=psim_unstable(zolza,psi_opt)-psim_unstable(zolz0,psi_opt)
908           psih(I)=psih_unstable(zolza,psi_opt)-psih_unstable(zolzt,psi_opt)
909           psim10(I)=psim_unstable(zol10,psi_opt)-psim_unstable(zolz0,psi_opt)
910           psih10(I)=psih_unstable(zol10,psi_opt)-psih_unstable(zolz0,psi_opt)
911           psih2(I)=psih_unstable(zol2,psi_opt)-psih_unstable(zolz0,psi_opt)
912        ELSE           
913           ! LAND  
914           !CALL PSI_Hogstrom_1996(PSIM(I),PSIH(I),ZOL(I), z_t(I), ZNTstoch(I), ZA(I))
915           !CALL PSI_Businger_1971(PSIM(I),PSIH(I),ZOL(I))
916           !CALL PSI_DyerHicks(PSIM(I),PSIH(I),ZOL(I),z_t(I),ZNTstoch(I),ZA(I))
917           ! use tables
918           psim(I)=psim_unstable(zolza,psi_opt)-psim_unstable(zolz0,psi_opt)
919           psih(I)=psih_unstable(zolza,psi_opt)-psih_unstable(zolzt,psi_opt)
920           psim10(I)=psim_unstable(zol10,psi_opt)-psim_unstable(zolz0,psi_opt)
921           psih10(I)=psih_unstable(zol10,psi_opt)-psih_unstable(zolz0,psi_opt)
922           psih2(I)=psih_unstable(zol2,psi_opt)-psih_unstable(zolz0,psi_opt)
923        ENDIF              
925        !PSIM10(I)=10./ZA(I)*PSIM(I)
926        !PSIH2(I)=2./ZA(I)*PSIH(I)
928        !---LIMIT PSIH AND PSIM IN THE CASE OF THIN LAYERS AND
929        !---HIGH ROUGHNESS.  THIS PREVENTS DENOMINATOR IN FLUXES
930        !---FROM GETTING TOO SMALL
931        PSIH(I)=MIN(PSIH(I),0.9*GZ1OZt(I))
932        PSIM(I)=MIN(PSIM(I),0.9*GZ1OZ0(I))
933        PSIH2(I)=MIN(PSIH2(I),0.9*GZ2OZt(I))
934        PSIM10(I)=MIN(PSIM10(I),0.9*GZ10OZ0(I))
935        PSIH10(I)=MIN(PSIH10(I),0.9*GZ10OZt(I))
937        RMOL(I) = ZOL(I)/ZA(I)  
939     ENDIF
941     !------------------------------------------------------------
942     !-----COMPUTE THE FRICTIONAL VELOCITY:                                           
943     !------------------------------------------------------------
944     !     ZA(1982) EQS(2.60),(2.61).
945     PSIX=GZ1OZ0(I)-PSIM(I)
946     PSIX10=GZ10OZ0(I)-PSIM10(I)
947     ! TO PREVENT OSCILLATIONS AVERAGE WITH OLD VALUE 
948     OLDUST = UST(I)
949     UST(I)=0.5*UST(I)+0.5*KARMAN*WSPD(I)/PSIX 
950     !NON-AVERAGED: UST(I)=KARMAN*WSPD(I)/PSIX
951      
952     ! Compute u* without vconv for use in HFX calc when isftcflx > 0           
953     WSPDI(I)=MAX(SQRT(U1D(I)*U1D(I)+V1D(I)*V1D(I)), wmin)
954     IF ( PRESENT(USTM) ) THEN
955        USTM(I)=0.5*USTM(I)+0.5*KARMAN*WSPDI(I)/PSIX
956     ENDIF
958     IF ((XLAND(I)-1.5).LT.0.) THEN        !LAND
959        UST(I)=MAX(UST(I),0.005)  !Further relaxing this limit - no need to go lower
960        !Keep ustm = ust over land.
961        IF ( PRESENT(USTM) ) USTM(I)=UST(I)
962     ENDIF
964     !------------------------------------------------------------
965     !-----COMPUTE THE THERMAL AND MOISTURE RESISTANCE (PSIQ AND PSIT):
966     !------------------------------------------------------------
967     ! LOWER LIMIT ADDED TO PREVENT LARGE FLHC IN SOIL MODEL
968     ! ACTIVATES IN UNSTABLE CONDITIONS WITH THIN LAYERS OR HIGH Z0
969     GZ1OZt(I)= LOG((ZA(I)+ZNTstoch(I))/z_t(i))
970     GZ2OZt(I)= LOG((2.0+ZNTstoch(I))/z_t(i))
972     PSIT =MAX(GZ1OZt(I)-PSIH(I) ,1.)
973     PSIT2=MAX(GZ2OZt(I)-PSIH2(I),1.)
975     PSIQ=MAX(LOG((ZA(I)+ZNTstoch(I))/z_q(I))-PSIH(I) ,1.0)
976     PSIQ2=MAX(LOG((2.0+ZNTstoch(I))/z_q(I))-PSIH2(I) ,1.0)
977     PSIQ10=MAX(LOG((10.0+ZNTstoch(I))/z_q(I))-PSIH10(I) ,1.0)
978     !----------------------------------------------------
979     !COMPUTE THE TEMPERATURE SCALE (or FRICTION TEMPERATURE, T*)
980     !----------------------------------------------------
981     DTG=THV1D(I)-THVGB(I)
982     OLDTST=MOL(I)
983     MOL(I)=KARMAN*DTG/PSIT/PRT
984     !t_star(I) = -HFX(I)/(UST(I)*CPM(I)*RHO1D(I))
985     !t_star(I) = MOL(I)
986     !----------------------------------------------------
987     !COMPUTE THE MOISTURE SCALE (or q*)
988     DQG=(QVSH(i)-qsfc(i))*1000.   !(kg/kg -> g/kg)
989     qstar(I)=KARMAN*DQG/PSIQ/PRT
991     !IF () THEN
992         !  write(*,1001)"REGIME:",REGIME(I)," z/L:",ZOL(I)," U*:",UST(I)," Tstar:",MOL(I)
993         !  write(*,1002)"PSIM:",PSIM(I)," PSIH:",PSIH(I)," W*:",WSTAR(I)," DTHV:",THV1D(I)-THVGB(I)
994         !  write(*,1003)"CPM:",CPM(I)," RHO1D:",RHO1D(I)," L:",ZOL(I)/ZA(I)," DTH:",TH1D(I)-THGB(I)
995         !  write(*,1004)"Z0/Zt:",zratio(I)," Z0:",ZNTstoch(I)," Zt:",z_t(I)," za:",za(I)
996         !  write(*,1005)"Re:",restar," MAVAIL:",MAVAIL(I)," QSFC(I):",QSFC(I)," QVSH(I):",QVSH(I)
997         !  print*,"VISC=",VISC," Z0:",ZNTstoch(I)," T1D(i):",T1D(i)
998         !  write(*,*)"============================================="
999     !ENDIF
1001  ENDDO     ! end i-loop
1003  1000   format(A,F6.1, A,f6.1, A,f5.1, A,f7.1)
1004  1001   format(A,F2.0, A,f10.4,A,f5.3, A,f11.5)
1005  1002   format(A,f7.2, A,f7.2, A,f7.2, A,f10.3)
1006  1003   format(A,f7.2, A,f7.2, A,f10.3,A,f10.3)
1007  1004   format(A,f11.3,A,f9.7, A,f9.7, A,f6.2, A,f10.3)
1008  1005   format(A,f9.2,A,f6.4,A,f7.4,A,f7.4)
1010       !----------------------------------------------------------
1011       !  COMPUTE SURFACE HEAT AND MOISTURE FLUXES
1012       !----------------------------------------------------------
1013  DO I=its,ite
1015     !For computing the diagnostics and fluxes (below), whether the fluxes
1016     !are turned off or on, we need the following:
1017     PSIX=GZ1OZ0(I)-PSIM(I)
1018     PSIX10=GZ10OZ0(I)-PSIM10(I)
1020     PSIT =MAX(GZ1OZt(I)-PSIH(I), 1.0)
1021     PSIT2=MAX(GZ2OZt(I)-PSIH2(I),1.0)
1022   
1023     PSIQ=MAX(LOG((ZA(I)+z_q(i))/z_q(I))-PSIH(I) ,1.0)
1024     PSIQ2=MAX(LOG((2.0+z_q(i))/z_q(I))-PSIH2(I) ,1.0)
1025     PSIQ10=MAX(LOG((10.0+z_q(i))/z_q(I))-PSIH10(I) ,1.0)
1027     IF (ISFFLX .LT. 1) THEN                            
1029        QFX(i)  = 0.                                                              
1030        HFX(i)  = 0.    
1031        FLHC(I) = 0.                                                             
1032        FLQC(I) = 0.                                                             
1033        LH(I)   = 0.                                                             
1034        CHS(I)  = 0.                                                             
1035        CH(I)   = 0.                                                             
1036        CHS2(i) = 0.                                                              
1037        CQS2(i) = 0.                                                              
1038        IF(PRESENT(ck)  .and. PRESENT(cd) .and. &
1039          &PRESENT(cka) .and. PRESENT(cda)) THEN
1040            Ck(I) = 0.
1041            Cd(I) = 0.
1042            Cka(I)= 0.
1043            Cda(I)= 0.
1044        ENDIF
1045     ELSE
1047       !------------------------------------------
1048       ! CALCULATE THE EXCHANGE COEFFICIENTS FOR HEAT (FLHC)
1049       ! AND MOISTURE (FLQC)
1050       !------------------------------------------
1051       FLQC(I)=RHO1D(I)*MAVAIL(I)*UST(I)*KARMAN/PSIQ
1052       FLHC(I)=RHO1D(I)*CPM(I)*UST(I)*KARMAN/PSIT
1054       !----------------------------------
1055       ! COMPUTE SURFACE MOISTURE FLUX:
1056       !----------------------------------
1057       QFX(I)=FLQC(I)*(QSFCMR(I)-QV1D(I))
1058       !JOE: QFX(I)=MAX(QFX(I),0.)   !originally did not allow neg QFX           
1059       QFX(I)=MAX(QFX(I),-0.02)      !allows small neg QFX, like MYJ
1060       LH(I)=XLV*QFX(I)
1062       !----------------------------------
1063       ! COMPUTE SURFACE HEAT FLUX:
1064       !----------------------------------
1065       IF(XLAND(I)-1.5.GT.0.)THEN      !WATER                                           
1066          HFX(I)=FLHC(I)*(THGB(I)-TH1D(I))                                
1067          IF ( PRESENT(ISFTCFLX) ) THEN
1068             IF ( ISFTCFLX.NE.0 ) THEN
1069                ! AHW: add dissipative heating term
1070                HFX(I)=HFX(I)+RHO1D(I)*USTM(I)*USTM(I)*WSPDI(I)
1071             ENDIF
1072          ENDIF
1073       ELSEIF(XLAND(I)-1.5.LT.0.)THEN  !LAND                               
1074          HFX(I)=FLHC(I)*(THGB(I)-TH1D(I))                                
1075          HFX(I)=MAX(HFX(I),-250.)                                       
1076       ENDIF
1078       !CHS(I)=UST(I)*KARMAN/(ALOG(KARMAN*UST(I)*ZA(I) &
1079       !       /XKA+ZA(I)/ZL)-PSIH(I))
1081       CHS(I)=UST(I)*KARMAN/PSIT
1083       ! The exchange coefficient for cloud water is assumed to be the 
1084       ! same as that for heat. CH is multiplied by WSPD.
1086       !ch(i)=chs(i)
1087       ch(i)=flhc(i)/( cpm(i)*RHO1D(i) )
1089       !THESE ARE USED FOR 2-M DIAGNOSTICS ONLY
1090       CQS2(I)=UST(I)*KARMAN/PSIQ2
1091       CHS2(I)=UST(I)*KARMAN/PSIT2
1093       IF(PRESENT(ck)  .and. PRESENT(cd) .and. &
1094         &PRESENT(cka) .and. PRESENT(cda)) THEN
1095          Ck(I)=(karman/psix10)*(karman/psiq10)
1096          Cd(I)=(karman/psix10)*(karman/psix10)
1097          Cka(I)=(karman/psix)*(karman/psiq)
1098          Cda(I)=(karman/psix)*(karman/psix)
1099       ENDIF
1101    ENDIF !end ISFFLX option
1103    !-----------------------------------------------------
1104    !COMPUTE DIAGNOSTICS
1105    !-----------------------------------------------------
1106    !COMPUTE 10 M WNDS
1107    !-----------------------------------------------------
1108    ! If the lowest model level is close to 10-m, use it
1109    ! instead of the flux-based diagnostic formula.
1110    if (ZA(i) .le. 7.0) then
1111       ! high vertical resolution
1112       if(ZA2(i) .gt. 7.0 .and. ZA2(i) .lt. 13.0) then
1113          !use 2nd model level
1114          U10(I)=U1D2(I)
1115          V10(I)=V1D2(I)
1116       else
1117          U10(I)=U1D(I)*log(10./ZNTstoch(I))/log(ZA(I)/ZNTstoch(I))
1118          V10(I)=V1D(I)*log(10./ZNTstoch(I))/log(ZA(I)/ZNTstoch(I))
1119       endif
1120    elseif(ZA(i) .gt. 7.0 .and. ZA(i) .lt. 13.0) then
1121       !moderate vertical resolution
1122       !U10(I)=U1D(I)*PSIX10/PSIX
1123       !V10(I)=V1D(I)*PSIX10/PSIX
1124       !use neutral-log:
1125       U10(I)=U1D(I)*log(10./ZNTstoch(I))/log(ZA(I)/ZNTstoch(I))
1126       V10(I)=V1D(I)*log(10./ZNTstoch(I))/log(ZA(I)/ZNTstoch(I))
1127    else
1128       ! very coarse vertical resolution
1129       U10(I)=U1D(I)*PSIX10/PSIX
1130       V10(I)=V1D(I)*PSIX10/PSIX
1131    endif
1133    !-----------------------------------------------------
1134    !COMPUTE 2m T, TH, AND Q
1135    !THESE WILL BE OVERWRITTEN FOR LAND POINTS IN THE LSM
1136    !-----------------------------------------------------
1137    DTG=TH1D(I)-THGB(I) 
1138    TH2(I)=THGB(I)+DTG*PSIT2/PSIT
1139    !***  BE CERTAIN THAT THE 2-M THETA IS BRACKETED BY
1140    !***  THE VALUES AT THE SURFACE AND LOWEST MODEL LEVEL.
1141    IF ((TH1D(I)>THGB(I) .AND. (TH2(I)<THGB(I) .OR. TH2(I)>TH1D(I))) .OR. &
1142        (TH1D(I)<THGB(I) .AND. (TH2(I)>THGB(I) .OR. TH2(I)<TH1D(I)))) THEN
1143        TH2(I)=THGB(I) + 2.*(TH1D(I)-THGB(I))/ZA(I)
1144    ENDIF
1145    T2(I)=TH2(I)*(PSFC(I)/100.)**ROVCP
1147    Q2(I)=QSFCMR(I)+(QV1D(I)-QSFCMR(I))*PSIQ2/PSIQ
1148    Q2(I)= MAX(Q2(I), MIN(QSFCMR(I), QV1D(I)))
1149    Q2(I)= MIN(Q2(I), 1.05*QV1D(I))
1151    IF ( debug_code ) THEN
1152       yesno = 0
1153       IF (HFX(I) > 1200. .OR. HFX(I) < -700.)THEN
1154             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1155             I,J, "HFX: ",HFX(I)
1156             yesno = 1
1157       ENDIF
1158       IF (LH(I)  > 1200. .OR. LH(I)  < -700.)THEN
1159             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1160             I,J, "LH: ",LH(I)
1161             yesno = 1
1162       ENDIF
1163       IF (UST(I) < 0.0 .OR. UST(I) > 4.0 )THEN
1164             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1165             I,J, "UST: ",UST(I)
1166             yesno = 1
1167       ENDIF
1168       IF (WSTAR(I)<0.0 .OR. WSTAR(I) > 6.0)THEN
1169             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1170             I,J, "WSTAR: ",WSTAR(I)
1171             yesno = 1
1172       ENDIF
1173       IF (RHO1D(I)<0.0 .OR. RHO1D(I) > 1.6 )THEN
1174             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1175             I,J, "rho: ",RHO1D(I)
1176             yesno = 1
1177       ENDIF
1178       IF (QSFC(I)*1000. <0.0 .OR. QSFC(I)*1000. >40.)THEN
1179             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1180             I,J, "QSFC: ",QSFC(I)
1181             yesno = 1
1182       ENDIF
1183       IF (PBLH(I)<0. .OR. PBLH(I)>6000.)THEN
1184             print*,"SUSPICIOUS VALUES IN MYNN SFCLAYER",&
1185             I,J, "PBLH: ",PBLH(I)
1186             yesno = 1
1187       ENDIF
1189       IF (yesno == 1) THEN
1190         print*," OTHER INFO:"
1191         write(*,1001)"REGIME:",REGIME(I)," z/L:",ZOL(I)," U*:",UST(I),&
1192               " Tstar:",MOL(I)
1193         write(*,1002)"PSIM:",PSIM(I)," PSIH:",PSIH(I)," W*:",WSTAR(I),&
1194               " DTHV:",THV1D(I)-THVGB(I)
1195         write(*,1003)"CPM:",CPM(I)," RHO1D:",RHO1D(I)," L:",&
1196               ZOL(I)/ZA(I)," DTH:",TH1D(I)-THGB(I)
1197         write(*,*)" Z0:",ZNTstoch(I)," Zt:",z_t(I)," za:",za(I)
1198         write(*,1005)"Re:",restar," MAVAIL:",MAVAIL(I)," QSFC(I):",&
1199               QSFC(I)," QVSH(I):",QVSH(I)
1200         print*,"PSIX=",PSIX," Z0:",ZNTstoch(I)," T1D(i):",T1D(i)
1201         write(*,*)"============================================="
1202       ENDIF
1203    ENDIF
1205  ENDDO !end i-loop
1207 END SUBROUTINE SFCLAY1D_mynn
1208 !-------------------------------------------------------------------          
1209    SUBROUTINE zilitinkevich_1995(Z_0,Zt,Zq,restar,ustar,KARMAN,&
1210        & landsea,IZ0TLND2,spp_pbl,rstoch)
1212        ! This subroutine returns the thermal and moisture roughness lengths
1213        ! from Zilitinkevich (1995) and Zilitinkevich et al. (2001) over
1214        ! land and water, respectively. 
1215        !
1216        ! MODS:
1217        ! 20120705 : added IZ0TLND option. Note: This option was designed
1218        !            to work with the Noah LSM and may be specific for that
1219        !            LSM only. Tests with RUC LSM showed no improvements. 
1221        IMPLICIT NONE
1222        REAL, INTENT(IN) :: Z_0,restar,ustar,KARMAN,landsea
1223        INTEGER, OPTIONAL, INTENT(IN)::  IZ0TLND2
1224        REAL, INTENT(OUT) :: Zt,Zq
1225        REAL :: CZIL  !=0.100 in Chen et al. (1997)
1226                      !=0.075 in Zilitinkevich (1995)
1227                      !=0.500 in Lemone et al. (2008)
1228        INTEGER,  INTENT(IN)  ::    spp_pbl
1229        REAL,     INTENT(IN)  ::    rstoch
1232        IF (landsea-1.5 .GT. 0) THEN    !WATER
1234           !THIS IS BASED ON Zilitinkevich, Grachev, and Fairall (2001;
1235           !Their equations 15 and 16).
1236           IF (restar .LT. 0.1) THEN
1237              Zt = Z_0*EXP(KARMAN*2.0)
1238              Zt = MIN( Zt, 6.0e-5)
1239              Zt = MAX( Zt, 2.0e-9)
1240              Zq = Z_0*EXP(KARMAN*3.0)
1241              Zq = MIN( Zq, 6.0e-5)
1242              Zq = MAX( Zq, 2.0e-9)
1243           ELSE
1244              Zt = Z_0*EXP(-KARMAN*(4.0*SQRT(restar)-3.2))
1245              Zt = MIN( Zt, 6.0e-5)
1246              Zt = MAX( Zt, 2.0e-9)
1247              Zq = Z_0*EXP(-KARMAN*(4.0*SQRT(restar)-4.2))
1248              Zq = MIN( Zt, 6.0e-5)
1249              Zq = MAX( Zt, 2.0e-9)
1250           ENDIF
1252        ELSE                             !LAND
1254           !Option to modify CZIL according to Chen & Zhang, 2009
1255           IF ( IZ0TLND2 .EQ. 1 ) THEN
1256              CZIL = 10.0 ** ( -0.40 * ( Z_0 / 0.07 ) )
1257           ELSE
1258              CZIL = 0.085 !0.075 !0.10
1259           END IF
1261           Zt = Z_0*EXP(-KARMAN*CZIL*SQRT(restar))
1262           Zt = MIN( Zt, 0.75*Z_0)
1264           Zq = Z_0*EXP(-KARMAN*CZIL*SQRT(restar))
1265           Zq = MIN( Zq, 0.75*Z_0)
1267 ! stochastically perturb thermal and moisture roughness length.
1268 ! currently set to half the amplitude: 
1269           if (spp_pbl==1) then
1270              Zt = Zt + Zt * 0.5 * rstoch
1271              Zt = MAX(Zt, 0.0001)
1272              Zq = Zt
1273           endif
1275        ENDIF
1276                    
1277        return
1279    END SUBROUTINE zilitinkevich_1995
1280 !--------------------------------------------------------------------
1281    SUBROUTINE davis_etal_2008(Z_0,ustar)
1283     !a.k.a. : Donelan et al. (2004)
1284     !This formulation for roughness length was designed to match 
1285     !the labratory experiments of Donelan et al. (2004).
1286     !This is an update version from Davis et al. 2008, which
1287     !corrects a small-bias in Z_0 (AHW real-time 2012).
1289        IMPLICIT NONE
1290        REAL, INTENT(IN)  :: ustar
1291        REAL, INTENT(OUT)  :: Z_0
1292        REAL :: ZW, ZN1, ZN2
1293        REAL, PARAMETER :: G=9.81, OZO=1.59E-5
1295        !OLD FORM: Z_0 = 10.*EXP(-10./(ustar**(1./3.)))
1296        !NEW FORM:
1298        ZW  = MIN((ustar/1.06)**(0.3),1.0)
1299        ZN1 = 0.011*ustar*ustar/G + OZO
1300        ZN2 = 10.*exp(-9.5*ustar**(-.3333)) + &
1301              0.11*1.5E-5/AMAX1(ustar,0.01)
1302        Z_0 = (1.0-ZW) * ZN1 + ZW * ZN2
1304        Z_0 = MAX( Z_0, 1.27e-7)  !These max/mins were suggested by
1305        Z_0 = MIN( Z_0, 2.85e-3)  !Davis et al. (2008)
1306                    
1307        return
1309    END SUBROUTINE davis_etal_2008
1310 !--------------------------------------------------------------------
1311    SUBROUTINE Taylor_Yelland_2001(Z_0,ustar,wsp10)
1313     !This formulation for roughness length was designed account for 
1314     !wave steepness.
1316        IMPLICIT NONE
1317        REAL, INTENT(IN)  :: ustar,wsp10
1318        REAL, INTENT(OUT) :: Z_0
1319        REAL, parameter  :: g=9.81, pi=3.14159265
1320        REAL :: hs, Tp, Lp
1322        !hs is the significant wave height
1323         hs = 0.0248*(wsp10**2.)
1324        !Tp dominant wave period
1325         Tp = 0.729*MAX(wsp10,0.1)
1326        !Lp is the wavelength of the dominant wave
1327         Lp = g*Tp**2/(2*pi)
1329        Z_0 = 1200.*hs*(hs/Lp)**4.5
1330        Z_0 = MAX( Z_0, 1.27e-7)  !These max/mins were suggested by
1331        Z_0 = MIN( Z_0, 2.85e-3)  !Davis et al. (2008)
1332                    
1333        return
1335    END SUBROUTINE Taylor_Yelland_2001
1336 !--------------------------------------------------------------------
1337    SUBROUTINE charnock_1955(Z_0,ustar,wsp10,visc,zu)
1339     !This version of Charnock's relation employs a varying
1340     !Charnock parameter, similar to COARE3.0 [Fairall et al. (2003)].
1341     !The Charnock parameter CZC is varied from .011 to .018 
1342     !between 10-m wsp = 10 and 18. 
1344        IMPLICIT NONE
1345        REAL, INTENT(IN)  :: ustar, visc, wsp10, zu
1346        REAL, INTENT(OUT) :: Z_0
1347        REAL, PARAMETER   :: G=9.81, CZO2=0.011
1348        REAL              :: CZC    !variable charnock "constant"   
1349        REAL              :: wsp10m ! logarithmically calculated 10 m
1351        wsp10m = wsp10*log(10./1e-4)/log(zu/1e-4)
1352        CZC = CZO2 + 0.007*MIN(MAX((wsp10m-10.)/8., 0.), 1.0)
1354        Z_0 = CZC*ustar*ustar/G + (0.11*visc/MAX(ustar,0.05))
1355        Z_0 = MAX( Z_0, 1.27e-7)  !These max/mins were suggested by
1356        Z_0 = MIN( Z_0, 2.85e-3)  !Davis et al. (2008)
1358        return
1360    END SUBROUTINE charnock_1955
1361 !--------------------------------------------------------------------
1362    SUBROUTINE edson_etal_2013(Z_0,ustar,wsp10,visc,zu)
1364      !This version of Charnock's relation employs a varying
1365      !Charnock parameter, taken from COARE 3.5 [Edson et al. (2001, JPO)].
1366      !The Charnock parameter CZC is varied from about .005 to .028
1367      !between 10-m wind speeds of 6 and 19 m/s.
1368      !11 Nov 2021: Note that this was finally fixed according to the
1369      !             Edson et al (2014) corrigendum, where "m" was corrected.
1371        IMPLICIT NONE
1372        REAL, INTENT(IN)  :: ustar, visc, wsp10, zu
1373        REAL, INTENT(OUT) :: Z_0
1374        REAL, PARAMETER   :: G=9.81
1375        REAL, PARAMETER   :: m=0.0017, b=-0.005
1376        REAL              :: CZC    ! variable charnock "constant"
1377        REAL              :: wsp10m ! logarithmically calculated 10 m
1379        wsp10m = wsp10*log(10/1e-4)/log(zu/1e-4)
1380        wsp10m = MIN(19., wsp10m)
1381        CZC    = m*wsp10m + b
1382        CZC    = MAX(CZC, 0.0)
1384        Z_0 = CZC*ustar*ustar/G + (0.11*visc/MAX(ustar,0.07))
1385        Z_0 = MAX( Z_0, 1.27e-7)  !These max/mins were suggested by
1386        Z_0 = MIN( Z_0, 2.85e-3)  !Davis et al. (2008)
1388        return
1390    END SUBROUTINE edson_etal_2013
1391 !--------------------------------------------------------------------
1392    SUBROUTINE garratt_1992(Zt,Zq,Z_0,Ren,landsea)
1394     !This formulation for the thermal and moisture roughness lengths
1395     !(Zt and Zq) relates them to Z0 via the roughness Reynolds number (Ren).
1396     !This formula comes from Fairall et al. (2003). It is modified from
1397     !the original Garratt-Brutsaert model to better fit the COARE/HEXMAX
1398     !data. The formula for land uses a constant ratio (Z_0/7.4) taken
1399     !from Garratt (1992).
1401        IMPLICIT NONE
1402        REAL, INTENT(IN)  :: Ren, Z_0,landsea
1403        REAL, INTENT(OUT) :: Zt,Zq
1404        REAL :: Rq
1405        REAL, PARAMETER  :: e=2.71828183
1407        IF (landsea-1.5 .GT. 0) THEN    !WATER
1409           Zt = Z_0*EXP(2.0 - (2.48*(Ren**0.25)))
1410           Zq = Z_0*EXP(2.0 - (2.28*(Ren**0.25)))
1412           Zq = MIN( Zq, 5.5e-5)
1413           Zq = MAX( Zq, 2.0e-9)
1414           Zt = MIN( Zt, 5.5e-5)
1415           Zt = MAX( Zt, 2.0e-9) !same lower limit as ECMWF
1416        ELSE                            !LAND
1417           Zq = Z_0/(e**2.)      !taken from Garratt (1980,1992)
1418           Zt = Zq
1419        ENDIF
1420                    
1421        return
1423     END SUBROUTINE garratt_1992
1424 !--------------------------------------------------------------------
1425     SUBROUTINE fairall_etal_2003(Zt,Zq,Ren,ustar,visc,rstoch,spp_pbl)
1427     !This formulation for thermal and moisture roughness length (Zt and Zq)
1428     !as a function of the roughness Reynolds number (Ren) comes from the
1429     !COARE3.0 formulation, empirically derived from COARE and HEXMAX data
1430     ![Fairall et al. (2003)]. Edson et al. (2004; JGR) suspected that this
1431     !relationship overestimated the scalar roughness lengths for low Reynolds
1432     !number flows, so an optional smooth flow relationship, taken from Garratt
1433     !(1992, p. 102), is available for flows with Ren < 2.
1434     !
1435     !This is for use over water only.
1437        IMPLICIT NONE
1438        REAL, INTENT(IN)   :: Ren,ustar,visc,rstoch
1439        INTEGER, INTENT(IN):: spp_pbl
1440        REAL, INTENT(OUT)  :: Zt,Zq
1442        IF (Ren .le. 2.) then
1444           Zt = (5.5e-5)*(Ren**(-0.60))
1445           Zq = Zt
1446           !FOR SMOOTH SEAS, CAN USE GARRATT
1447           !Zq = 0.2*visc/MAX(ustar,0.1)
1448           !Zq = 0.3*visc/MAX(ustar,0.1)
1450        ELSE
1452           !FOR ROUGH SEAS, USE COARE
1453           Zt = (5.5e-5)*(Ren**(-0.60))
1454           Zq = Zt
1456        ENDIF
1458        if (spp_pbl==1) then
1459           Zt = Zt + Zt * 0.5 * rstoch
1460           Zq = Zt
1461        endif
1463        Zt = MIN(Zt,1.0e-4)
1464        Zt = MAX(Zt,2.0e-9)
1466        Zq = MIN(Zt,1.0e-4)
1467        Zq = MAX(Zt,2.0e-9)
1469        return
1471     END SUBROUTINE fairall_etal_2003
1472 !--------------------------------------------------------------------
1473     SUBROUTINE fairall_etal_2014(Zt,Zq,Ren,ustar,visc,rstoch,spp_pbl)
1475     !This formulation for thermal and moisture roughness length (Zt and Zq)
1476     !as a function of the roughness Reynolds number (Ren) comes from the
1477     !COARE 3.5/4.0 formulation, empirically derived from COARE and HEXMAX data
1478     ![Fairall et al. (2014? coming soon, not yet published as of July 2014)].
1479     !This is for use over water only.
1481        IMPLICIT NONE
1482        REAL, INTENT(IN)  :: Ren,ustar,visc,rstoch
1483        INTEGER, INTENT(IN):: spp_pbl
1484        REAL, INTENT(OUT) :: Zt,Zq
1486        !Zt = (5.5e-5)*(Ren**(-0.60))
1487        Zt = MIN(1.6E-4, 5.8E-5/(Ren**0.72))
1488        Zq = Zt
1490        IF (spp_pbl ==1) THEN
1491           Zt = MAX(Zt + Zt*0.5*rstoch,2.0e-9)
1492           Zq = MAX(Zt + Zt*0.5*rstoch,2.0e-9)
1493        ELSE
1494           Zt = MAX(Zt,2.0e-9)
1495           Zq = MAX(Zt,2.0e-9)
1496        ENDIF
1498        return
1500     END SUBROUTINE fairall_etal_2014
1501 !--------------------------------------------------------------------
1502     SUBROUTINE Yang_2008(Z_0,Zt,Zq,ustar,tstar,qst,Ren,visc,landsea)
1504     !This is a modified version of Yang et al (2002 QJRMS, 2008 JAMC) 
1505     !and Chen et al (2010, J of Hydromet). Although it was originally 
1506     !designed for arid regions with bare soil, it is modified 
1507     !here to perform over a broader spectrum of vegetation.
1508     !
1509     !The original formulation relates the thermal roughness length (Zt) 
1510     !to u* and T*:
1511     !  
1512     ! Zt = ht * EXP(-beta*(ustar**0.5)*(ABS(tstar)**0.25))
1513     !
1514     !where ht = Renc*visc/ustar and the critical Reynolds number 
1515     !(Renc) = 70. Beta was originally = 10 (2002 paper) but was revised 
1516     !to 7.2 (in 2008 paper). Their form typically varies the
1517     !ratio Z0/Zt by a few orders of magnitude (1-1E4).
1518     !
1519     !This modified form uses beta = 1.5 and a variable Renc (function of Z_0),
1520     !so zt generally varies similarly to the Zilitinkevich form (with Czil ~ 0.1)
1521     !for very small or negative surface heat fluxes but can become close to the
1522     !Zilitinkevich with Czil = 0.2 for very large HFX (large negative T*).
1523     !Also, the exponent (0.25) on tstar was changed to 1.0, since we found
1524     !Zt was reduced too much for low-moderate positive heat fluxes.
1525     !
1526     !This should only be used over land!
1528        IMPLICIT NONE
1529        REAL, INTENT(IN)  :: Z_0, Ren, ustar, tstar, qst, visc, landsea
1530        REAL              :: ht,     &! roughness height at critical Reynolds number
1531                             tstar2, &! bounded T*, forced to be non-positive
1532                             qstar2, &! bounded q*, forced to be non-positive
1533                             Z_02,   &! bounded Z_0 for variable Renc2 calc
1534                             Renc2    ! variable Renc, function of Z_0
1535        REAL, INTENT(OUT) :: Zt,Zq
1536        REAL, PARAMETER  :: Renc=300., & !old constant Renc
1537                            beta=1.5,  & !important for diurnal variation
1538                            m=170.,    & !slope for Renc2 function
1539                            b=691.       !y-intercept for Renc2 function
1541        Z_02 = MIN(Z_0,0.5)
1542        Z_02 = MAX(Z_02,0.04)
1543        Renc2= b + m*log(Z_02)
1544        ht     = Renc2*visc/MAX(ustar,0.01)
1545        tstar2 = MIN(tstar, 0.0)
1546        qstar2 = MIN(qst,0.0)
1548        Zt     = ht * EXP(-beta*(ustar**0.5)*(ABS(tstar2)**1.0))
1549        Zq     = ht * EXP(-beta*(ustar**0.5)*(ABS(qstar2)**1.0))
1550        !Zq     = Zt
1552        Zt = MIN(Zt, Z_0/2.0)
1553        Zq = MIN(Zq, Z_0/2.0)
1555        return
1557     END SUBROUTINE Yang_2008
1558 !--------------------------------------------------------------------
1559     SUBROUTINE Andreas_2002(Z_0,bvisc,ustar,Zt,Zq)
1561     ! This is taken from Andreas (2002; J. of Hydromet) and 
1562     ! Andreas et al. (2005; BLM).
1563     !
1564     ! This should only be used over snow/ice!
1566        IMPLICIT NONE
1567        REAL, INTENT(IN)  :: Z_0, bvisc, ustar
1568        REAL, INTENT(OUT) :: Zt, Zq
1569        REAL :: Ren2, zntsno
1571        REAL, PARAMETER  :: bt0_s=1.25,  bt0_t=0.149,  bt0_r=0.317,  &
1572                            bt1_s=0.0,   bt1_t=-0.55,  bt1_r=-0.565, &
1573                            bt2_s=0.0,   bt2_t=0.0,    bt2_r=-0.183
1575        REAL, PARAMETER  :: bq0_s=1.61,  bq0_t=0.351,  bq0_r=0.396,  &
1576                            bq1_s=0.0,   bq1_t=-0.628, bq1_r=-0.512, &
1577                            bq2_s=0.0,   bq2_t=0.0,    bq2_r=-0.180
1579       !Calculate zo for snow (Andreas et al. 2005, BLM)                                                                     
1580        zntsno = 0.135*bvisc/ustar + &
1581                (0.035*(ustar*ustar)/9.8) * &
1582                (5.*exp(-1.*(((ustar - 0.18)/0.1)*((ustar - 0.18)/0.1))) + 1.)                                                
1583        Ren2 = ustar*zntsno/bvisc
1585        ! Make sure that Re is not outside of the range of validity
1586        ! for using their equations
1587        IF (Ren2 .gt. 1000.) Ren2 = 1000. 
1589        IF (Ren2 .le. 0.135) then
1591           Zt = zntsno*EXP(bt0_s + bt1_s*LOG(Ren2) + bt2_s*LOG(Ren2)**2)
1592           Zq = zntsno*EXP(bq0_s + bq1_s*LOG(Ren2) + bq2_s*LOG(Ren2)**2)
1594        ELSE IF (Ren2 .gt. 0.135 .AND. Ren2 .lt. 2.5) then
1596           Zt = zntsno*EXP(bt0_t + bt1_t*LOG(Ren2) + bt2_t*LOG(Ren2)**2)
1597           Zq = zntsno*EXP(bq0_t + bq1_t*LOG(Ren2) + bq2_t*LOG(Ren2)**2)
1599        ELSE
1601           Zt = zntsno*EXP(bt0_r + bt1_r*LOG(Ren2) + bt2_r*LOG(Ren2)**2)
1602           Zq = zntsno*EXP(bq0_r + bq1_r*LOG(Ren2) + bq2_r*LOG(Ren2)**2)
1604        ENDIF
1606        return
1608     END SUBROUTINE Andreas_2002
1609 !--------------------------------------------------------------------
1610     SUBROUTINE PSI_Hogstrom_1996(psi_m, psi_h, zL, Zt, Z_0, Za)
1612     ! This subroutine returns the stability functions based off
1613     ! of Hogstrom (1996).
1615        IMPLICIT NONE
1616        REAL, INTENT(IN)  :: zL, Zt, Z_0, Za
1617        REAL, INTENT(OUT) :: psi_m, psi_h
1618        REAL  :: x, x0, y, y0, zmL, zhL
1620        zmL = Z_0*zL/Za  
1621        zhL = Zt*zL/Za
1623        IF (zL .gt. 0.) THEN  !STABLE (not well tested - seem large)
1625           psi_m = -5.3*(zL - zmL)
1626           psi_h = -8.0*(zL - zhL)
1628        ELSE                 !UNSTABLE
1630           x = (1.-19.0*zL)**0.25
1631           x0= (1.-19.0*zmL)**0.25
1632           y = (1.-11.6*zL)**0.5
1633           y0= (1.-11.6*zhL)**0.5
1635           psi_m = 2.*LOG((1.+x)/(1.+x0)) + &
1636                     &LOG((1.+x**2.)/(1.+x0**2.)) - &
1637                     &2.0*ATAN(x) + 2.0*ATAN(x0)
1638           psi_h = 2.*LOG((1.+y)/(1.+y0))
1640        ENDIF
1641                    
1642        return
1644     END SUBROUTINE PSI_Hogstrom_1996
1645 !--------------------------------------------------------------------
1646     SUBROUTINE PSI_DyerHicks(psi_m, psi_h, zL, Zt, Z_0, Za)
1648     ! This subroutine returns the stability functions based off
1649     ! of Hogstrom (1996), but with different constants compatible
1650     ! with Dyer and Hicks (1970/74?). This formulation is used for
1651     ! testing/development by Nakanishi (personal communication).
1653        IMPLICIT NONE
1654        REAL, INTENT(IN)  :: zL, Zt, Z_0, Za
1655        REAL, INTENT(OUT) :: psi_m, psi_h
1656        REAL  :: x, x0, y, y0, zmL, zhL
1658        zmL = Z_0*zL/Za  !Zo/L
1659        zhL = Zt*zL/Za   !Zt/L
1661        IF (zL .gt. 0.) THEN  !STABLE
1663           psi_m = -5.0*(zL - zmL)
1664           psi_h = -5.0*(zL - zhL)
1666        ELSE                 !UNSTABLE
1668           x = (1.-16.*zL)**0.25
1669           x0= (1.-16.*zmL)**0.25
1671           y = (1.-16.*zL)**0.5
1672           y0= (1.-16.*zhL)**0.5
1674           psi_m = 2.*LOG((1.+x)/(1.+x0)) + &
1675                     &LOG((1.+x**2.)/(1.+x0**2.)) - & 
1676                     &2.0*ATAN(x) + 2.0*ATAN(x0)
1677           psi_h = 2.*LOG((1.+y)/(1.+y0))
1679        ENDIF
1680                    
1681        return
1683     END SUBROUTINE PSI_DyerHicks
1684 !--------------------------------------------------------------------
1685     SUBROUTINE PSI_Beljaars_Holtslag_1991(psi_m, psi_h, zL)
1687     ! This subroutine returns the stability functions based off
1688     ! of Beljaar and Holtslag 1991, which is an extension of Holtslag
1689     ! and Debruin 1989.
1691        IMPLICIT NONE
1692        REAL, INTENT(IN)  :: zL
1693        REAL, INTENT(OUT) :: psi_m, psi_h
1694        REAL, PARAMETER  :: a=1., b=0.666, c=5., d=0.35
1696        IF (zL .lt. 0.) THEN  !UNSTABLE
1698           WRITE(*,*)"WARNING: Universal stability functions from"
1699           WRITE(*,*)"        Beljaars and Holtslag (1991) should only"
1700           WRITE(*,*)"        be used in the stable regime!"
1701           psi_m = 0.
1702           psi_h = 0.
1704        ELSE                 !STABLE
1706           psi_m = -(a*zL + b*(zL -(c/d))*exp(-d*zL) + (b*c/d))
1707           psi_h = -((1.+.666*a*zL)**1.5 + &
1708                   b*(zL - (c/d))*exp(-d*zL) + (b*c/d) -1.)
1710        ENDIF
1711                    
1712        return
1714     END SUBROUTINE PSI_Beljaars_Holtslag_1991
1715 !--------------------------------------------------------------------
1716     SUBROUTINE PSI_Zilitinkevich_Esau_2007(psi_m, psi_h, zL)
1718     ! This subroutine returns the stability functions come from
1719     ! Zilitinkevich and Esau (2007, BM), which are formulatioed from the
1720     ! "generalized similarity theory" and tuned to the LES DATABASE64
1721     ! to determine their dependence on z/L.
1723        IMPLICIT NONE
1724        REAL, INTENT(IN)  :: zL
1725        REAL, INTENT(OUT) :: psi_m, psi_h
1726        REAL, PARAMETER  :: Cm=3.0, Ct=2.5
1728        IF (zL .lt. 0.) THEN  !UNSTABLE
1730           WRITE(*,*)"WARNING: Universal stability function from"
1731           WRITE(*,*)"        Zilitinkevich and Esau (2007) should only"
1732           WRITE(*,*)"        be used in the stable regime!"
1733           psi_m = 0.
1734           psi_h = 0.
1736        ELSE                 !STABLE
1738           psi_m = -Cm*(zL**(5./6.))
1739           psi_h = -Ct*(zL**(4./5.))
1741        ENDIF
1742                    
1743        return
1745     END SUBROUTINE PSI_Zilitinkevich_Esau_2007
1746 !--------------------------------------------------------------------
1747     SUBROUTINE PSI_Businger_1971(psi_m, psi_h, zL)
1749     ! This subroutine returns the flux-profile relationships
1750     ! of Businger el al. 1971.
1752        IMPLICIT NONE
1753        REAL, INTENT(IN)  :: zL
1754        REAL, INTENT(OUT) :: psi_m, psi_h
1755        REAL  :: x, y
1756        REAL, PARAMETER  ::  Pi180 = 3.14159265/180.
1758        IF (zL .lt. 0.) THEN  !UNSTABLE
1760           x = (1. - 15.0*zL)**0.25
1761           y = (1. - 9.0*zL)**0.5
1763           psi_m = LOG(((1.+x)/2.)**2.) + &
1764                  &LOG((1.+x**2.)/2.) - &
1765                  &2.0*ATAN(x) + Pi180*90.
1766           psi_h = 2.*LOG((1.+y)/2.)
1768        ELSE                 !STABLE
1770           psi_m = -4.7*zL
1771           psi_h = -(4.7/0.74)*zL
1773        ENDIF
1774                    
1775        return
1777     END SUBROUTINE PSI_Businger_1971
1778 !--------------------------------------------------------------------
1779     SUBROUTINE PSI_Suselj_Sood_2010(psi_m, psi_h, zL)
1781     !This subroutine returns flux-profile relatioships based off
1782     !of Lobocki (1993), which is derived from the MY-level 2 model.
1783     !Suselj and Sood (2010) applied the surface layer length scales
1784     !from Nakanishi (2001) to get this new relationship. These functions
1785     !are more agressive (larger magnitude) than most formulations. They
1786     !showed improvement over water, but untested over land.
1788        IMPLICIT NONE
1789        REAL, INTENT(IN)  :: zL
1790        REAL, INTENT(OUT) :: psi_m, psi_h
1791        REAL, PARAMETER  :: Rfc=0.19, Ric=0.183, PHIT=0.8
1793        IF (zL .gt. 0.) THEN  !STABLE
1795           psi_m = -(zL/Rfc + 1.1223*EXP(1.-1.6666/zL))
1796           !psi_h = -zL*Ric/((Rfc**2.)*PHIT) + 8.209*(zL**1.1091)
1797           !THEIR EQ FOR PSI_H CRASHES THE MODEL AND DOES NOT MATCH
1798           !THEIR FIG 1. THIS EQ (BELOW) MATCHES THEIR FIG 1 BETTER:
1799           psi_h = -(zL*Ric/((Rfc**2.)*5.) + 7.09*(zL**1.1091))
1801        ELSE                 !UNSTABLE
1803           psi_m = 0.9904*LOG(1. - 14.264*zL)
1804           psi_h = 1.0103*LOG(1. - 16.3066*zL)
1806        ENDIF
1807                    
1808        return
1810     END SUBROUTINE PSI_Suselj_Sood_2010
1811 !--------------------------------------------------------------------
1812     SUBROUTINE PSI_CB2005(psim1,psih1,zL,z0L)
1814     ! This subroutine returns the stability functions based off
1815     ! of Cheng and Brutseart (2005, BLM), for use in stable conditions only.
1816     ! The returned values are the combination of psi((za+zo)/L) - psi(z0/L)
1818        IMPLICIT NONE
1819        REAL, INTENT(IN)  :: zL,z0L
1820        REAL, INTENT(OUT) :: psim1,psih1
1822        psim1 = -6.1*LOG(zL  + (1.+ zL **2.5)**0.4) &
1823                -6.1*LOG(z0L + (1.+ z0L**2.5)**0.4)
1824        psih1 = -5.5*LOG(zL  + (1.+ zL **1.1)**0.90909090909) &
1825                -5.5*LOG(z0L + (1.+ z0L**1.1)**0.90909090909)
1827        return
1829     END SUBROUTINE PSI_CB2005
1830 !--------------------------------------------------------------------
1831     SUBROUTINE Li_etal_2010(zL, Rib, zaz0, z0zt)
1833     !This subroutine returns a more robust z/L that best matches
1834     !the z/L from Hogstrom (1996) for unstable conditions and Beljaars
1835     !and Holtslag (1991) for stable conditions.
1837        IMPLICIT NONE
1838        REAL, INTENT(OUT)  :: zL
1839        REAL, INTENT(IN) :: Rib, zaz0, z0zt
1840        REAL :: alfa, beta, zaz02, z0zt2
1841        REAL, PARAMETER  :: au11=0.045, bu11=0.003, bu12=0.0059, &
1842                           &bu21=-0.0828, bu22=0.8845, bu31=0.1739, &
1843                           &bu32=-0.9213, bu33=-0.1057
1844        REAL, PARAMETER  :: aw11=0.5738, aw12=-0.4399, aw21=-4.901,&
1845                           &aw22=52.50, bw11=-0.0539, bw12=1.540, &
1846                           &bw21=-0.669, bw22=-3.282
1847        REAL, PARAMETER  :: as11=0.7529, as21=14.94, bs11=0.1569,&
1848                           &bs21=-0.3091, bs22=-1.303
1849           
1850        !set limits according to Li et al (2010), p 157.
1851        zaz02=zaz0
1852        IF (zaz0 .lt. 100.0) zaz02=100.
1853        IF (zaz0 .gt. 100000.0) zaz02=100000.
1855        !set more limits according to Li et al (2010)
1856        z0zt2=z0zt
1857        IF (z0zt .lt. 0.5) z0zt2=0.5
1858        IF (z0zt .gt. 100.0) z0zt2=100.
1860        alfa = LOG(zaz02)
1861        beta = LOG(z0zt2)
1863        IF (Rib .le. 0.0) THEN
1864           zL = au11*alfa*Rib**2 + (                   &
1865                &  (bu11*beta + bu12)*alfa**2 +        &
1866                &  (bu21*beta + bu22)*alfa    +        &
1867                &  (bu31*beta**2 + bu32*beta + bu33))*Rib
1868           !if(zL .LT. -15 .OR. zl .GT. 0.)print*,"VIOLATION Rib<0:",zL
1869           zL = MAX(zL,-15.) !LIMITS SET ACCORDING TO Li et al (2010)
1870           zL = MIN(zL,0.)   !Figure 1.
1871        ELSEIF (Rib .gt. 0.0 .AND. Rib .le. 0.2) THEN
1872           zL = ((aw11*beta + aw12)*alfa +             &
1873              &  (aw21*beta + aw22))*Rib**2 +          &
1874              & ((bw11*beta + bw12)*alfa +             &
1875              &  (bw21*beta + bw22))*Rib
1876           !if(zL .LT. 0 .OR. zl .GT. 4)print*,"VIOLATION 0<Rib<0.2:",zL
1877           zL = MIN(zL,4.) !LIMITS APPROX SET ACCORDING TO Li et al (2010)
1878           zL = MAX(zL,0.) !THEIR FIGURE 1B.
1879        ELSE
1880           zL = (as11*alfa + as21)*Rib + bs11*alfa +   &
1881              &  bs21*beta + bs22
1882           !if(zL .LE. 1 .OR. zl .GT. 23)print*,"VIOLATION Rib>0.2:",zL
1883           zL = MIN(zL,20.) !LIMITS ACCORDING TO Li et al (2010), THIER
1884                            !FIGUE 1C.
1885           zL = MAX(zL,1.)
1886        ENDIF
1888        return
1890     END SUBROUTINE Li_etal_2010
1891 !-------------------------------------------------------------------
1892       REAL function zolri(ri,za,z0,zt,zol1,psi_opt)
1894       ! This iterative algorithm is a two-point secant method taken from the revised 
1895       ! surface layer scheme in WRF-ARW, written by Pedro Jimenez and Jimy Dudhia and 
1896       ! summarized in Jimenez et al. (2012, MWR). This function was adapted
1897       ! to input the thermal roughness length, zt, (as well as z0) and use initial
1898       ! estimate of z/L.
1900       IMPLICIT NONE
1901       REAL, INTENT(IN) :: ri,za,z0,zt,zol1
1902       INTEGER, INTENT(IN) :: psi_opt
1903       REAL :: x1,x2,fx1,fx2
1904       INTEGER :: n
1905       INTEGER, PARAMETER :: nmax = 20
1907       if (ri.lt.0.)then
1908          x1=zol1 - 0.02  !-5.
1909          x2=0.
1910       else
1911          x1=0.
1912          x2=zol1 + 0.02 !5.
1913       endif
1915       n=0
1916       fx1=zolri2(x1,ri,za,z0,zt,psi_opt)
1917       fx2=zolri2(x2,ri,za,z0,zt,psi_opt)
1918         
1919       Do While (abs(x1 - x2) > 0.01 .and. n < nmax)
1920         if(abs(fx2) .lt. abs(fx1))then
1921           x1=x1-fx1/(fx2-fx1)*(x2-x1)
1922           fx1=zolri2(x1,ri,za,z0,zt,psi_opt)
1923           zolri=x1
1924         else
1925           x2=x2-fx2/(fx2-fx1)*(x2-x1)
1926           fx2=zolri2(x2,ri,za,z0,zt,psi_opt)
1927           zolri=x2
1928         endif
1929         n=n+1
1930       enddo
1932       if (n==nmax .and. abs(x1 - x2) >= 0.01) then
1933          !if convergence fails, use approximate values:
1934          CALL Li_etal_2010(zolri, ri, za/z0, z0/zt)
1935          !print*,"FAILED, n=",n," Ri=",ri," zt=",zt
1936       else
1937          !print*,"SUCCESS,n=",n," Ri=",ri," z/L=",zolri
1938       endif
1940       return
1941       end function
1942 !-------------------------------------------------------------------
1943       REAL function zolri2(zol2,ri2,za,z0,zt,psi_opt)
1945       ! INPUT: =================================
1946       ! zol2 - estimated z/L
1947       ! ri2  - calculated bulk Richardson number
1948       ! za   - 1/2 depth of first model layer
1949       ! z0   - aerodynamic roughness length
1950       ! zt   - thermal roughness length
1951       ! OUTPUT: ================================
1952       ! zolri2 - delta Ri
1954       IMPLICIT NONE
1955       INTEGER, INTENT(IN) :: psi_opt
1956       REAL, INTENT(IN) :: ri2,za,z0,zt
1957       REAL, INTENT(INOUT) :: zol2
1958       REAL :: zol20,zol3,psim1,psih1,psix2,psit2,zolt
1960       if(zol2*ri2 .lt. 0.) THEN
1961          !print*,"WRONG QUADRANTS: z/L=",zol2," ri=",ri2
1962          zol2=0.
1963       endif 
1965       zol20=zol2*z0/za ! z0/L
1966       zol3=zol2+zol20  ! (z+z0)/L
1967       zolt=zol2*zt/za  ! zt/L 
1969       if (ri2.lt.0) then
1970          psit2=MAX(log((za+z0)/zt)-(psih_unstable(zol3,psi_opt)-psih_unstable(zolt,psi_opt)), 1.0)
1971          psix2=MAX(log((za+z0)/z0)-(psim_unstable(zol3,psi_opt)-psim_unstable(zol20,psi_opt)),1.0)
1972       else
1973          psit2=MAX(log((za+z0)/zt)-(psih_stable(zol3,psi_opt)-psih_stable(zolt,psi_opt)), 1.0)
1974          psix2=MAX(log((za+z0)/z0)-(psim_stable(zol3,psi_opt)-psim_stable(zol20,psi_opt)),1.0)
1975       endif
1977       zolri2=zol2*psit2/psix2**2 - ri2
1978       !print*,"  target ri=",ri2," est ri=",zol2*psit2/psix2**2
1980       return
1981       end function
1982 !====================================================================
1984       REAL function zolrib(ri,za,z0,zt,logz0,logzt,zol1,psi_opt)
1986       ! This iterative algorithm to compute z/L from bulk-Ri
1988       IMPLICIT NONE
1989       REAL, INTENT(IN) :: ri,za,z0,zt,logz0,logzt
1990       INTEGER, INTENT(IN) :: psi_opt
1991       REAL, INTENT(INOUT) :: zol1
1992       REAL :: zol20,zol3,zolt,zolold
1993       INTEGER :: n
1994       INTEGER, PARAMETER :: nmax = 20
1995       !REAL, DIMENSION(nmax):: zLhux
1996       REAL :: psit2,psix2
1998       if(zol1*ri .lt. 0.) THEN
1999          !print*,"WRONG QUADRANTS: z/L=",zol1," ri=",ri
2000          zol1=0.
2001       endif
2003       if (ri .lt. 0.) then
2004         zolold=-99999.
2005         zolrib=-66666.
2006       else
2007         zolold=99999.
2008         zolrib=66666.
2009       endif
2010       n=1
2012       DO While (abs(zolold - zolrib) > 0.01 .and. n < nmax)
2014         if(n==1)then
2015           zolold=zol1
2016         else
2017           zolold=zolrib
2018         endif
2019         zol20=zolold*z0/za ! z0/L
2020         zol3=zolold+zol20  ! (z+z0)/L
2021         zolt=zolold*zt/za  ! zt/L
2023         if (ri.lt.0) then
2024            psit2=MAX(logzt-(psih_unstable(zol3,psi_opt)-psih_unstable(zolt,psi_opt)), 1.0)
2025            psix2=MAX(logz0-(psim_unstable(zol3,psi_opt)-psim_unstable(zol20,psi_opt)), 1.0)
2026         else
2027            psit2=MAX(logzt-(psih_stable(zol3,psi_opt)-psih_stable(zolt,psi_opt)), 1.0)
2028            psix2=MAX(logz0-(psim_stable(zol3,psi_opt)-psim_stable(zol20,psi_opt)), 1.0)
2029         endif
2031         zolrib=ri*psix2**2/psit2
2032         !zLhux(n)=zolrib
2033         n=n+1
2034       enddo
2036       if (n==nmax .and. abs(zolold - zolrib) > 0.01 ) then
2037          !print*,"iter FAIL, n=",n," Ri=",ri," z/L=",zolri
2038          !if convergence fails, use approximate values:
2039          CALL Li_etal_2010(zolrib, ri, za/z0, z0/zt)
2040          !zLhux(n)=zolri
2041          !print*,"FAILED, n=",n," Ri=",ri," zt=",zt
2042          !print*,"z/L=",zLhux(1:nmax)
2043       else
2044          !print*,"SUCCESS,n=",n," Ri=",ri," z/L=",zolrib
2045       endif
2047       return
2048       end function
2049 !====================================================================
2051    SUBROUTINE psi_init(psi_opt)
2053     ! Define tables from -10 <= z/L <= 10
2055     INTEGER                   ::      N,psi_opt
2056     REAL                      ::      zolf
2058     if (psi_opt == 0) then
2059        DO N=0,1000
2060           ! stable function tables
2061           zolf = float(n)*0.01
2062           psim_stab(n)=psim_stable_full(zolf)
2063           psih_stab(n)=psih_stable_full(zolf)
2065           ! unstable function tables
2066           zolf = -float(n)*0.01
2067           psim_unstab(n)=psim_unstable_full(zolf)
2068           psih_unstab(n)=psih_unstable_full(zolf)
2069        ENDDO
2070     else
2071        DO N=0,1000
2072           ! stable function tables
2073           zolf = float(n)*0.01
2074           psim_stab(n)=psim_stable_full_gfs(zolf)
2075           psih_stab(n)=psih_stable_full_gfs(zolf)
2077           ! unstable function tables
2078           zolf = -float(n)*0.01
2079           psim_unstab(n)=psim_unstable_full_gfs(zolf)
2080           psih_unstab(n)=psih_unstable_full_gfs(zolf)
2081        ENDDO
2082     endif
2084    END SUBROUTINE psi_init
2085 ! ==================================================================
2086 ! ... Full equations for the integrated similarity functions ...
2087 ! ==================================================================
2088    REAL function psim_stable_full(zolf)
2089         REAL :: zolf   
2091         psim_stable_full=-6.1*log(zolf+(1+zolf**2.5)**(1./2.5))
2093         return
2094    end function
2096    REAL function psih_stable_full(zolf)
2097         REAL :: zolf
2099         psih_stable_full=-5.3*log(zolf+(1+zolf**1.1)**(1./1.1))
2101         return
2102    end function
2104    REAL function psim_unstable_full(zolf)
2105         REAL :: zolf,x,ym,psimc,psimk
2107         x=(1.-16.*zolf)**.25
2108         psimk=2*ALOG(0.5*(1+X))+ALOG(0.5*(1+X*X))-2.*ATAN(X)+2.*ATAN(1.)
2110         ym=(1.-10.*zolf)**0.33
2111         psimc=(3./2.)*log((ym**2.+ym+1.)/3.)-sqrt(3.)*ATAN((2.*ym+1)/sqrt(3.))+4.*ATAN(1.)/sqrt(3.)
2113         psim_unstable_full=(psimk+zolf**2*(psimc))/(1+zolf**2.)
2115         return
2116    end function
2118    REAL function psih_unstable_full(zolf)
2119         REAL :: zolf,y,yh,psihc,psihk
2121         y=(1.-16.*zolf)**.5
2122         psihk=2.*log((1+y)/2.)
2124         yh=(1.-34.*zolf)**0.33
2125         psihc=(3./2.)*log((yh**2.+yh+1.)/3.)-sqrt(3.)*ATAN((2.*yh+1)/sqrt(3.))+4.*ATAN(1.)/sqrt(3.)
2127         psih_unstable_full=(psihk+zolf**2*(psihc))/(1+zolf**2.)
2129         return
2130    end function
2132 ! ==================================================================
2133 ! ... integrated similarity functions from GFS...
2135    REAL function psim_stable_full_gfs(zolf)
2136         REAL :: zolf
2137         REAL, PARAMETER :: alpha4 = 20.
2138         REAL :: aa
2140         aa     = sqrt(1. + alpha4 * zolf)
2141         psim_stable_full_gfs  = -1.*aa + log(aa + 1.)
2143         return
2144    end function
2146    REAL function psih_stable_full_gfs(zolf)
2147         REAL :: zolf
2148         REAL, PARAMETER :: alpha4 = 20.
2149         REAL :: bb
2151         bb     = sqrt(1. + alpha4 * zolf)
2152         psih_stable_full_gfs  = -1.*bb + log(bb + 1.)
2154         return
2155    end function
2157    REAL function psim_unstable_full_gfs(zolf)
2158         REAL :: zolf
2159         REAL :: hl1,tem1
2160         REAL, PARAMETER :: a0=-3.975,  a1=12.32,  &
2161                            b1=-7.755,  b2=6.041
2163         if (zolf .ge. -0.5) then
2164            hl1   = zolf
2165            psim_unstable_full_gfs  = (a0  + a1*hl1)  * hl1   / (1.+ (b1+b2*hl1)  *hl1)
2166         else
2167            hl1   = -zolf
2168            tem1  = 1.0 / sqrt(hl1)
2169            psim_unstable_full_gfs  = log(hl1) + 2. * sqrt(tem1) - .8776
2170         end if
2172         return
2173    end function
2175    REAL function psih_unstable_full_gfs(zolf)
2176         REAL :: zolf
2177         REAL :: hl1,tem1
2178         REAL, PARAMETER :: a0p=-7.941, a1p=24.75, &
2179                            b1p=-8.705, b2p=7.899
2181         if (zolf .ge. -0.5) then
2182            hl1   = zolf
2183            psih_unstable_full_gfs  = (a0p + a1p*hl1) * hl1   / (1.+ (b1p+b2p*hl1)*hl1)
2184         else
2185            hl1   = -zolf
2186            tem1  = 1.0 / sqrt(hl1)
2187            psih_unstable_full_gfs  = log(hl1) + .5 * tem1 + 1.386
2188         end if
2190         return
2191    end function
2193 !=================================================================
2194 ! These functions use the look-up table functions when |z/L| <= 10
2195 ! but default to the full equations when |z/L| > 10.  
2196 !=================================================================
2197    REAL function psim_stable(zolf,psi_opt)
2198         integer :: nzol,psi_opt
2199         real    :: rzol,zolf
2201         nzol = int(zolf*100.)
2202         rzol = zolf*100. - nzol
2203         if(nzol+1 .le. 1000)then
2204            psim_stable = psim_stab(nzol) + rzol*(psim_stab(nzol+1)-psim_stab(nzol))
2205         else
2206            if (psi_opt == 0) then
2207               psim_stable = psim_stable_full(zolf)
2208            else
2209               psim_stable = psim_stable_full_gfs(zolf)
2210            endif
2211         endif
2213       return
2214    end function
2216    REAL function psih_stable(zolf,psi_opt)
2217         integer :: nzol,psi_opt
2218         real    :: rzol,zolf
2220         nzol = int(zolf*100.)
2221         rzol = zolf*100. - nzol
2222         if(nzol+1 .le. 1000)then
2223            psih_stable = psih_stab(nzol) + rzol*(psih_stab(nzol+1)-psih_stab(nzol))
2224         else
2225            if (psi_opt == 0) then
2226               psih_stable = psih_stable_full(zolf)
2227            else
2228               psih_stable = psih_stable_full_gfs(zolf)
2229            endif
2230         endif
2232       return
2233    end function
2235    REAL function psim_unstable(zolf,psi_opt)
2236         integer :: nzol,psi_opt
2237         real    :: rzol,zolf
2239         nzol = int(-zolf*100.)
2240         rzol = -zolf*100. - nzol
2241         if(nzol+1 .le. 1000)then
2242            psim_unstable = psim_unstab(nzol) + rzol*(psim_unstab(nzol+1)-psim_unstab(nzol))
2243         else
2244            if (psi_opt == 0) then
2245               psim_unstable = psim_unstable_full(zolf)
2246            else
2247               psim_unstable = psim_unstable_full_gfs(zolf)
2248            endif
2249         endif
2251       return
2252    end function
2254    REAL function psih_unstable(zolf,psi_opt)
2255         integer :: nzol,psi_opt
2256         real    :: rzol,zolf
2258         nzol = int(-zolf*100.)
2259         rzol = -zolf*100. - nzol
2260         if(nzol+1 .le. 1000)then
2261            psih_unstable = psih_unstab(nzol) + rzol*(psih_unstab(nzol+1)-psih_unstab(nzol))
2262         else
2263            if (psi_opt == 0) then
2264               psih_unstable = psih_unstable_full(zolf)
2265            else
2266               psih_unstable = psih_unstable_full_gfs(zolf)
2267            endif
2268         endif
2270       return
2271    end function
2272 !========================================================================
2274 END MODULE module_sf_mynn