| 1 |
c swd -- bulkf formula used in bulkf and ice pkgs |
| 2 |
|
| 3 |
c taken from exf package |
| 4 |
#include "CPP_OPTIONS.h" |
| 5 |
subroutine bulkf_formula_exf( |
| 6 |
I uw, vw, us, Ta, Qa, nc, tsf_in, |
| 7 |
I flwup, flha, fsha, df0dT, |
| 8 |
I ust, vst, evp, ssq, iceornot, windread |
| 9 |
& ) |
| 10 |
|
| 11 |
IMPLICIT NONE |
| 12 |
c |
| 13 |
#include "EEPARAMS.h" |
| 14 |
#include "SIZE.h" |
| 15 |
#include "PARAMS.h" |
| 16 |
#include "DYNVARS.h" |
| 17 |
#include "GRID.h" |
| 18 |
#include "FFIELDS.h" |
| 19 |
#ifdef ALLOW_BULKFORMULA |
| 20 |
#include "BULKF_ICE_CONSTANTS.h" |
| 21 |
#include "BULKF.h" |
| 22 |
#endif |
| 23 |
|
| 24 |
c |
| 25 |
c calculate bulk formula fluxes over open ocean or seaice |
| 26 |
c |
| 27 |
c input |
| 28 |
_RL us ! wind speed |
| 29 |
_RL uw ! zonal wind speed (at grid center) |
| 30 |
_RL vw ! meridional wind speed (at grid center) |
| 31 |
_RL Ta ! air temperature at ht |
| 32 |
_RL Qa ! specific humidity at ht |
| 33 |
_RL tsf_in ! surface temperature (either ice or open water) |
| 34 |
_RL nc ! fraction cloud cover |
| 35 |
integer iceornot ! 0=open water, 1=ice cover |
| 36 |
logical windread ! |
| 37 |
c output |
| 38 |
_RL flwup ! upward long wave radiation |
| 39 |
_RL flha ! latent heat flux |
| 40 |
_RL fsha ! sensible heat flux |
| 41 |
_RL df0dT ! derivative of heat flux with respect to Tsf |
| 42 |
_RL ust ! zonal wind stress (at grid center) |
| 43 |
_RL vst ! meridional wind stress (at grid center) |
| 44 |
_RL evp ! evaporation rate (over open water) |
| 45 |
_RL ssq ! surface specific humidity (kg/kg) |
| 46 |
c |
| 47 |
c local variables |
| 48 |
_RL tsf ! surface temperature in K |
| 49 |
_RL ht ! reference height (m) |
| 50 |
_RL hq ! reference height for humidity (m) |
| 51 |
_RL hu ! reference height for wind speed (m) |
| 52 |
_RL zref ! reference height |
| 53 |
_RL czol |
| 54 |
_RL usm ! wind speed limited |
| 55 |
_RL t0 ! virtual temperature (K) |
| 56 |
_RL deltap ! potential temperature diff (K) |
| 57 |
_RL delq ! specific humidity difference |
| 58 |
_RL stable |
| 59 |
_RL rdn |
| 60 |
_RL ustar |
| 61 |
_RL tstar |
| 62 |
_RL qstar |
| 63 |
_RL huol |
| 64 |
_RL htol |
| 65 |
_RL hqol |
| 66 |
_RL xsq |
| 67 |
_RL x |
| 68 |
_RL re |
| 69 |
_RL rh |
| 70 |
_RL tau |
| 71 |
_RL psimh |
| 72 |
_RL psixh |
| 73 |
_RL rd |
| 74 |
_RL uzn |
| 75 |
_RL shn |
| 76 |
_RL aln |
| 77 |
_RL cdalton |
| 78 |
_RL dflhdT ! derivative of latent heat with respect to T |
| 79 |
_RL dfshdT ! derivative of sensible heat with respect to T |
| 80 |
_RL dflwupdT ! derivative of long wave with respect to T |
| 81 |
_RL mixratio |
| 82 |
_RL ea |
| 83 |
_RL psim_fac |
| 84 |
_RL umin |
| 85 |
integer niter_bulk, iter |
| 86 |
|
| 87 |
#ifdef ALLOW_BULKFORMULA |
| 88 |
|
| 89 |
c --- external functions --- |
| 90 |
_RL exf_BulkCdn |
| 91 |
external exf_BulkCdn |
| 92 |
_RL exf_BulkqSat |
| 93 |
external exf_BulkqSat |
| 94 |
_RL exf_BulkRhn |
| 95 |
external exf_BulkRhn |
| 96 |
|
| 97 |
c -- compute turbulent surface fluxes |
| 98 |
ht = 2.d0 |
| 99 |
hq = 2.d0 |
| 100 |
hu = 10.d0 |
| 101 |
zref = 10.d0 |
| 102 |
aln = log(ht/zref) |
| 103 |
niter_bulk = 2 |
| 104 |
cdalton = 0.0346000 |
| 105 |
czol = hu*xkar*gravity |
| 106 |
psim_fac=5.d0 |
| 107 |
umin=5.d-1 |
| 108 |
c |
| 109 |
Tsf=Tsf_in+Tf0kel |
| 110 |
c Wind speed |
| 111 |
if (us.eq.0) then |
| 112 |
us = sqrt(uw*uw + vw*vw) |
| 113 |
endif |
| 114 |
usm = max(us,umin) |
| 115 |
cQQQ try to limit drag |
| 116 |
cQQ usm = min(usm,5.d0) |
| 117 |
c |
| 118 |
t0 = Ta*(1.d0 + humid_fac*Qa) |
| 119 |
ssq = saltsat*exf_BulkqSat(Tsf)/rhoa |
| 120 |
cBB debugging |
| 121 |
cBB print*,'ice, ssq', qcoef, ssq |
| 122 |
c |
| 123 |
deltap = ta - tsf + gamma_blk*ht |
| 124 |
delq = Qa - ssq |
| 125 |
stable = 5.d-1 + sign(5.d-1, deltap) |
| 126 |
rdn=sqrt(exf_BulkCdn(usm)) |
| 127 |
ustar=rdn*usm |
| 128 |
tstar=exf_BulkRhn(stable)*deltap |
| 129 |
qstar=cdalton*delq |
| 130 |
c |
| 131 |
c interation with psi-functions to find transfer coefficients |
| 132 |
do iter=1,niter_bulk |
| 133 |
huol = czol*(tstar/t0 + |
| 134 |
& qstar/(1.d0/humid_fac+Qa))/ |
| 135 |
& ustar**2 |
| 136 |
huol = max(huol,-100.d0) |
| 137 |
huol = min(huol, 100.d0) |
| 138 |
stable = .5d0+ sign(.5d0, huol) |
| 139 |
htol = huol*ht/hu |
| 140 |
hqol = huol*hq/hu |
| 141 |
|
| 142 |
c Evaluate all stability functions assuming hq = ht. |
| 143 |
xsq = max(sqrt(abs(1.d0 - 16.*huol)),1.d0) |
| 144 |
x = sqrt(xsq) |
| 145 |
psimh = -psim_fac*huol*stable + |
| 146 |
& (1.d0 - stable)* |
| 147 |
& log((1.d0 + x*(2.d0 + x))* |
| 148 |
& (1.d0 + xsq)/8.d0) - 2.d0*atan(x) + |
| 149 |
& pi*.5d0 |
| 150 |
xsq = max(sqrt(abs(1.d0 - 16.*htol)),1.d0) |
| 151 |
psixh = -psim_fac*htol*stable + (1.d0 - stable)* |
| 152 |
& 2.d0*log((1.d0 + xsq)/2.d0) |
| 153 |
|
| 154 |
c Shift wind speed using old coefficient |
| 155 |
ccc rd = rdn/(1.d0 + rdn/xkar* |
| 156 |
ccc & (log(hu/zref) - psimh) ) |
| 157 |
rd = rdn/(1.d0 - rdn/xkar*psimh ) |
| 158 |
shn = us*rd/rdn |
| 159 |
uzn = max(shn, umin) |
| 160 |
|
| 161 |
c Update the transfer coefficients at 10 meters and neutral stability. |
| 162 |
|
| 163 |
rdn = sqrt(exf_BulkCdn(uzn)) |
| 164 |
|
| 165 |
c Shift all coefficients to the measurement height and stability. |
| 166 |
c rd = rdn/(1.d0 + rdn/xkar*(log(hu/zref) - psimh)) |
| 167 |
rd = rdn/(1.d0 - rdn/xkar*psimh) |
| 168 |
rh = exf_BulkRhn(stable)/(1.d0 + |
| 169 |
& exf_BulkRhn(stable)/ |
| 170 |
& xkar*(aln - psixh)) |
| 171 |
re = cdalton/(1.d0 + cdalton/xkar*(aln - psixh)) |
| 172 |
|
| 173 |
c Update ustar, tstar, qstar using updated, shifted coefficients. |
| 174 |
ustar = rd*usm |
| 175 |
qstar = re*delq |
| 176 |
tstar = rh*deltap |
| 177 |
enddo |
| 178 |
c |
| 179 |
tau = rhoa*ustar**2 |
| 180 |
tau = tau*us/usm |
| 181 |
fsha = cpair*tau*tstar/ustar |
| 182 |
flha = Lvap *tau*qstar/ustar |
| 183 |
evp = tau*qstar/ustar |
| 184 |
c |
| 185 |
|
| 186 |
c up long wave radiation |
| 187 |
mixratio=Qa/(1-Qa) |
| 188 |
ea=p0*mixratio/(0.62197+mixratio) |
| 189 |
flwup=-0.985*stefan*tsf**4 |
| 190 |
& *(0.39-0.05*sqrt(ea)) |
| 191 |
& *(1-0.6*nc**2) |
| 192 |
#ifdef ALLOW_TSEAICE |
| 193 |
if (iceornot.eq.1) then |
| 194 |
c derivatives with respect to Tsf |
| 195 |
dflhdT = -(Lvap*tau*re*ssq/ustar)/(tsf**2) |
| 196 |
dfshdT = -cpair*tau*rh/ustar |
| 197 |
dflwupdT=-4.*0.985*stefan*tsf**3 |
| 198 |
& *(0.39-0.05*sqrt(ea)) |
| 199 |
c total derivative with respect to surface temperature |
| 200 |
df0dT=dflwupdT+dfshdT+dflhdT |
| 201 |
cBB |
| 202 |
cBB print*,'derivatives:',df0dT,dflwupdT,dfshdT,dflhdT |
| 203 |
endif |
| 204 |
#endif /*ALLOW_TSEAICE*/ |
| 205 |
c |
| 206 |
c wind stress at center points |
| 207 |
if (.NOT.windread) then |
| 208 |
ust = rhoa*exf_BulkCdn(usm)*us*uw |
| 209 |
vst = rhoa*exf_BulkCdn(usm)*us*vw |
| 210 |
endif |
| 211 |
#endif /*ALLOW_BULKFORMULA*/ |
| 212 |
ssq=deltap |
| 213 |
|
| 214 |
return |
| 215 |
end |
Parent Directory
| 
Revision Log
| 
Revision Graph