1 !WRF:MODEL_LAYER:CONSTANTS
4 MODULE module_model_constants
6 ! 2. Following are constants for use in defining real number bounds.
8 ! A really small number.
10 REAL , PARAMETER :: epsilon = 1.E-15
12 ! 4. Following is information related to the physical constants.
14 ! These are the physical constants used within the model.
16 ! JM NOTE -- can we name this grav instead?
17 REAL , PARAMETER :: g = 9.81 ! acceleration due to gravity (m {s}^-2)
19 REAL , PARAMETER :: r_d = 287. ! gas constant of dry air (J deg^-1 kg^-1)
20 REAL , PARAMETER :: cp = 7.*r_d/2. !
22 REAL , PARAMETER :: r_v = 461.6 ! gas constant for water vapor (J deg^-1 kg^-1)
23 REAL , PARAMETER :: cv = cp-r_d ! Specific heat of air at contant volume (J deg^-1 kg^-1)
24 REAL , PARAMETER :: cpv = 4.*r_v
25 REAL , PARAMETER :: cvv = cpv-r_v !
26 REAL , PARAMETER :: cvpm = -cv/cp
27 REAL , PARAMETER :: cliq = 4190. ! specific heat of liquid water at 0^oC
28 REAL , PARAMETER :: cice = 2106. ! specific heat of ice at 0^oC
29 REAL , PARAMETER :: psat = 610.78
30 REAL , PARAMETER :: rcv = r_d/cv !
31 REAL , PARAMETER :: rcp = r_d/cp
32 REAL , PARAMETER :: rovg = r_d/g
33 REAL , PARAMETER :: c2 = cp * rcv
34 real , parameter :: mwdry = 28.966 ! molecular weight of dry air (g/mole)
36 REAL , PARAMETER :: p1000mb = 100000. ! pressure at 1000 hPa (pa)
37 REAL , PARAMETER :: t0 = 300. ! base state tempertaure (K)
38 REAL , PARAMETER :: p0 = p1000mb ! base state surface pressure (pa)
39 REAL , PARAMETER :: cpovcv = cp/(cp-r_d)
40 REAL , PARAMETER :: cvovcp = 1./cpovcv
41 REAL , PARAMETER :: rvovrd = r_v/r_d
43 REAL , PARAMETER :: reradius = 1./6370.0e03 ! reciprocal of earth radius (m^-1)
45 REAL , PARAMETER :: asselin = .025
46 ! REAL , PARAMETER :: asselin = .0
47 REAL , PARAMETER :: cb = 25.
49 REAL , PARAMETER :: XLV0 = 3.15E6 ! constant defined for calculation of latent heating
50 REAL , PARAMETER :: XLV1 = 2370. ! constant defined for calculation of latent heating
51 REAL , PARAMETER :: XLS0 = 2.905E6 ! constant defined for calculation of latent heating
52 REAL , PARAMETER :: XLS1 = 259.532 ! constant defined for calculation of latent heating
54 REAL , PARAMETER :: XLS = 2.85E6 ! latent heat of sublimation of water at 0^oC (J kg^-1)
55 REAL , PARAMETER :: XLV = 2.5E6 ! latent heat of vaporization of water at 0^oC (J kg^-1)
56 REAL , PARAMETER :: XLF = 3.50E5 ! latent heat of fusion of water at 0^oC (J kg^-1)
58 REAL , PARAMETER :: rhowater = 1000. ! density of liquid water at 0^oC (kg m^-3)
59 REAL , PARAMETER :: rhosnow = 100. ! density of snow (kg m^-3)
60 REAL , PARAMETER :: rhoair0 = 1.28 ! density of dry air at 0^oC and 1000mb pressure (kg m^-3)
62 REAL , PARAMETER :: RE_QC_BG = 2.49E-6 ! effective radius of cloud for background (m)
63 REAL , PARAMETER :: RE_QI_BG = 4.99E-6 ! effective radius of ice for background (m)
64 REAL , PARAMETER :: RE_QS_BG = 9.99E-6 ! effective radius of snow for background (m)
66 ! Now namelist-specified parameter: ccn_conc - RAS
67 ! REAL , PARAMETER :: n_ccn0 = 1.0E8
69 REAL , PARAMETER :: piconst = 3.1415926535897932384626433 ! constant of PI
70 REAL , PARAMETER :: DEGRAD = piconst/180. ! radians per degree
71 REAL , PARAMETER :: DPD = 360./365.
73 REAL , PARAMETER :: SVP1=0.6112 ! constant for saturation vapor pressure calculation (dimensionless)
74 REAL , PARAMETER :: SVP2=17.67 ! constant for saturation vapor pressure calculation (dimensionless)
75 REAL , PARAMETER :: SVP3=29.65 ! constant for saturation vapor pressure calculation (K)
76 REAL , PARAMETER :: SVPT0=273.15 ! constant for saturation vapor pressure calculation (K)
77 REAL , PARAMETER :: EP_1=R_v/R_d-1. ! constant for virtual temperature (r_v/r_d - 1) (dimensionless)
78 REAL , PARAMETER :: EP_2=R_d/R_v ! constant for specific humidity calculation (dimensionless)
79 REAL , PARAMETER :: KARMAN=0.4 ! von Karman constant
80 REAL , PARAMETER :: EOMEG=7.2921E-5 ! angular velocity of rotation (rad^-1)
81 REAL , PARAMETER :: STBOLT=5.67051E-8 ! Stefan-Boltzmann constant (W m^-2 deg^-4)
83 REAL , PARAMETER :: prandtl = 1./3.0 ! prandtl's mixing length (m)
84 ! constants for w-damping option
85 REAL , PARAMETER :: w_alpha = 0.3 ! strength m/s/s
86 REAL , PARAMETER :: w_beta = 1.0 ! activation cfl number
88 REAL , PARAMETER :: pq0=379.90516 !
89 REAL , PARAMETER :: epsq2=0.2 ! initial TKE for camuw PBL scheme (m2 s^-2)
90 REAL , PARAMETER :: a2=17.2693882
91 REAL , PARAMETER :: a3=273.16
92 REAL , PARAMETER :: a4=35.86
93 REAL , PARAMETER :: epsq=1.e-12 ! threshold specified for SPECIFIC HUMIDITY calculation in BMJ cumulus scheme (kg kg^-1)
94 REAL , PARAMETER :: p608=rvovrd-1.
95 REAL , PARAMETER :: climit=1.e-20
96 REAL , PARAMETER :: cm1=2937.4
97 REAL , PARAMETER :: cm2=4.9283
98 REAL , PARAMETER :: cm3=23.5518
99 ! REAL , PARAMETER :: defc=8.0
100 ! REAL , PARAMETER :: defm=32.0
101 REAL , PARAMETER :: defc=0.0
102 REAL , PARAMETER :: defm=99999.0
103 REAL , PARAMETER :: epsfc=1./1.05
104 REAL , PARAMETER :: epswet=0.0
105 REAL , PARAMETER :: fcdif=1./3.
106 REAL , PARAMETER :: fcm=0.00003
107 REAL , PARAMETER :: gma=-r_d*(1.-rcp)*0.5
108 REAL , PARAMETER :: p400=40000.0
109 REAL , PARAMETER :: phitp=15000.0
110 REAL , PARAMETER :: pi2=2.*3.1415926, pi1=3.1415926
111 REAL , PARAMETER :: plbtm=105000.0
112 REAL , PARAMETER :: plomd=64200.0
113 REAL , PARAMETER :: pmdhi=35000.0
114 REAL , PARAMETER :: q2ini=0.50
115 REAL , PARAMETER :: rfcp=0.25/cp
116 REAL , PARAMETER :: rhcrit_land=0.75
117 REAL , PARAMETER :: rhcrit_sea=0.80
118 REAL , PARAMETER :: rlag=14.8125
119 REAL , PARAMETER :: rlx=0.90
120 REAL , PARAMETER :: scq2=50.0
121 REAL , PARAMETER :: slopht=0.001
122 REAL , PARAMETER :: tlc=2.*0.703972477
123 REAL , PARAMETER :: wa=0.15
124 REAL , PARAMETER :: wght=0.35
125 REAL , PARAMETER :: wpc=0.075
126 REAL , PARAMETER :: z0land=0.10 ! surface roughness length over land (m)
127 REAL , PARAMETER :: z0max=0.008 ! maximum roughness length (m)
128 REAL , PARAMETER :: z0sea=0.001 ! roughness length over ocean (m)
133 ! The value for P2SI *must* be set to 1.0 for Earth
134 ! Although, now we may not need this declaration here (see above)
135 !REAL , PARAMETER :: P2SI = 1.0
139 INTEGER , PARAMETER :: PLANET_YEAR = 365 ! number of days in a calendar year
140 REAL , PARAMETER :: OBLIQUITY = 23.5 ! solar obliquity (degree)
141 REAL , PARAMETER :: ECCENTRICITY = 0.014 ! Orbital eccentricity
142 REAL , PARAMETER :: SEMIMAJORAXIS = 1.0 ! Ratio of semi-major axis of planet / semi-major axis of earth
143 REAL , PARAMETER :: zero_date = 0.0 ! Time of perihelion passage
144 REAL , PARAMETER :: EQUINOX_FRACTION= 0.0 ! Fraction into the year (from perhelion) of the occurrence of the Northern Spring Equinox
148 ! for calls to set_tiles
149 INTEGER, PARAMETER :: ZONE_SOLVE_EM = 1
150 INTEGER, PARAMETER :: ZONE_SFS = 2
154 SUBROUTINE init_module_model_constants
155 END SUBROUTINE init_module_model_constants
156 END MODULE module_model_constants