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C $Header: /u/gcmpack/MITgcm/pkg/cheapaml/cheapaml_coare3_flux.F,v 1.2 2011/02/24 16:11:41 wienders Exp $ |
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C $Name: $ |
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|
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#include "CHEAPAML_OPTIONS.h" |
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|
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C !ROUTINE: CHEAPAML_COARE3_flux |
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C !INTERFACE: |
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subroutine cheapaml_COARE3_flux |
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&(i,j,bi,bj,hf,ef,evap,Rnl,ssqt,q100) |
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c |
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implicit none |
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "CHEAPAML.h" |
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#include "DYNVARS.h" |
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|
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integer iter,i,j,bi,bj,nits |
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_RL hf,ef,evap,tau,L,psu,pst,Bf |
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_RL CD,usr,tsr,qsr,q100,ssqt,ttas,essqt |
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_RL zo,zot,zoq,RR,zL,pt,ttt,tta |
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_RL Rnl,es,twopi,cwave,lwave |
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ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc |
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c various constants |
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c |
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_RL u,ts,q,zi,qs,tsw |
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_RL psiu,psit,zot10,Ct10,CC,Ribu |
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_RL Du,Wg,Dt,Dq,u10,zo10,Cd10,Ch10 |
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_RL xBeta,visa,Ribcu,QaR |
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_RL Ct,zetu,L10,Tas,ta,charn |
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c |
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c |
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c Constants and coefficients (Stull 1988 p640). |
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xBeta=1.2 !Given as 1.25 in Fairall et al.(1996) |
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twopi=2. _d 0*pi |
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visa=1.326 _d -5 |
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c default relative humidity |
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QaR=0.8 _d 0 |
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|
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c sea surface temperature without skin correction |
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ts=theta(i,j,1,bi,bj) |
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tsw=ts |
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Tas=Tair(i,j,bi,bj) |
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|
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|
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c net upward long wave |
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Rnl= 0.97*(stefan*(tsw+Celsius2K)**4) !Net longwave (up = +). |
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c |
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c Teten''s returns air svp es in mb |
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es = (1.0007+3.46e-6*p0)*6.1121*dexp(17.502*tsw/(240.97+tsw)) !mb |
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es=es*0.98 !reduced for salinity Kraus 1972 p. 46 |
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qs=.62197*es/(p0-0.378*es) !convert from mb to spec. humidity kg/kg |
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tta=Tas+Celsius2K |
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ttas=tta+gamma_blk*zt |
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ttt=tta-(cheapaml_h - zt)*gamma_blk |
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pt=p0*(1-gamma_blk*cheapaml_h/ttas)**(gravity/gamma_blk/gasR) |
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essqt = (1.0007+3.46e-6*pt)*6.1121*dexp(17.502*tas/(240.97+tas)) !mb |
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ssqt = .62197*essqt/(pt-0.378*essqt) !convert from mb to spec. humidity kg/kg |
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|
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if (useFreshWaterFlux)then |
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q=qair(i,j,bi,bj) |
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else |
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q=QaR*ssqt |
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endif |
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|
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|
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c Wave parameters |
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cwave=gravity*wavesp(i,j,bi,bj)/twopi |
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lwave=cwave*wavesp(i,j,bi,bj) |
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c |
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c Initial guesses |
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zo=0.0001 |
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Wg=0.5 !Gustiness factor initial guess |
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c |
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c Air-sea differences - includes warm layer in Dt and Dq |
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u=(uwind(i,j,bi,bj)-uVel(i,j,1,bi,bj))**2+ |
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&(vwind(i,j,bi,bj)-vVel(i,j,1,bi,bj))**2 |
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u=dsqrt(u) |
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Du=(u**2.+Wg**2.)**.5 !include gustiness in wind spd. difference |
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Dt=tsw-Tas-gamma_blk*zt !potential temperature difference. |
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Dq=qs-q |
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c |
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c **************** neutral coefficients ****************** |
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c |
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u10=Du*dlog(10. _d 0/zo)/dlog(zu/zo) |
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usr=0.035*u10 |
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zo10=0.011*usr*usr/gravity+0.11*visa/usr |
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Cd10=(xkar/dlog(10. _d 0/zo10))**2 |
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Ch10=0.00115 _d 0 |
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Ct10=Ch10/sqrt(Cd10) |
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zot10=10._d 0/dexp(xkar/Ct10) |
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Cd=(xkar/dlog(zu/zo10))**2 |
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|
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c standard coare3 boundary layer height |
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zi=600. _d 0 |
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|
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c |
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c ************* Grachev and Fairall (JAM, 1997) ********** |
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c |
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ta=Tas+Celsius2K |
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Ct=xkar/dlog(zt/zot10) ! Temperature transfer coefficient |
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CC=xkar*Ct/Cd ! z/L vs Rib linear coefficient |
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Ribcu=-zu/(zi*0.004 _d 0*xBeta**3) ! Saturation or plateau Rib |
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Ribu=-gravity*zu*(Dt+0.61 _d 0*ta*Dq)/(ta*Du**2) |
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if (Ribu.lt.0. _d 0) then |
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zetu=CC*Ribu/(1. _d 0+Ribu/Ribcu) ! Unstable G and F |
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else |
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zetu=CC*Ribu*(1. _d 0 +27. _d 0/9. _d 0*Ribu/CC) ! Stable |
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endif |
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L10=zu/zetu ! MO length |
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if (zetu.gt.50. _d 0) then |
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nits=1 |
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else |
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nits=3 ! number of iterations |
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endif |
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c |
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c First guess M-O stability dependent scaling params.(u*,t*,q*) to estimate zo and z/L |
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c |
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usr= Du*xkar/(dlog(zu/zo10)-psiu(zu/L10)) |
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tsr=-(Dt)*xkar/(dlog(zt/zot10)-psit(zt/L10)) |
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qsr=-(Dq)*xkar/(dlog(zq/zot10)-psit(zq/L10)) |
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c |
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charn=0.011 _d 0 !then modify Charnock for high wind speeds Chris s data |
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if(Du.gt.10. _d 0) charn=0.011 _d 0 |
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& +(0.018-0.011)*(Du-10.)/(18.0-10.0) |
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if(Du.gt.18. _d 0) charn=0.018 _d 0 |
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c |
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c **** Iterate across u*(t*,q*),zo(zot,zoq) and z/L including cool skin **** |
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c |
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do iter=1,nits |
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if(WAVEMODEL.eq.'Smith') then |
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zo=charn*usr*usr/gravity + 0.11 _d 0*visa/usr !after Smith 1988 |
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else if(WAVEMODEL.eq.'Oost') then |
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zo=(50./twopi)*lwave*(usr/cwave)**4.5 _d 0+0.11*visa/usr !Oost et al. |
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else if(WAVEMODEL.eq.'TayYel') then |
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zo=1200. _d 0*wavesh(i,j,bi,bj)*(wavesh(i,j,bi,bj)/lwave)**4.5 |
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& +0.11 _d 0*visa/usr !Taylor and Yelland |
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endif |
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rr=zo*usr/visa |
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c |
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c *** zoq and zot fitted to results from several ETL cruises ************ |
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c |
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zoq=min(1.15 _d -4,5.5 _d -5/rr**0.6 _d 0) |
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zot=zoq |
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c |
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zL=xkar*gravity*zu*(tsr*(1.+0.61*q)+0.61*ta*qsr) |
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& /(ta*usr*usr*(1. _d 0+0.61 _d 0*q)) |
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L=zu/zL |
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psu=psiu(zu/L) |
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pst=psit(zt/L) |
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usr=Du*xkar/(dlog(zu/zo)-psiu(zu/L)) |
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tsr=-(Dt)*xkar/(dlog(zt/zot)-psit(zt/L)) |
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qsr=-(Dq)*xkar/(dlog(zq/zoq)-psit(zq/L)) |
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Bf=-gravity/ta*usr*(tsr+0.61 _d 0*ta*qsr) |
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if (Bf.gt.0. _d 0) then |
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Wg=xBeta*(Bf*zi)**.333 _d 0 |
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else |
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Wg=0.2 _d 0 |
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endif |
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Du=sqrt(u**2.+Wg**2.) !include gustiness in wind spd. |
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enddo |
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|
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c compute surface fluxes and other parameters |
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tau=rhoa*usr*usr*u/Du !stress N/m2 |
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hf=-cpair*rhoa*usr*tsr !sensible W/m2 |
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ef=-lath*rhoa*usr*qsr !latent W/m2 |
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evap=-rhoa*usr*qsr |
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if(.NOT.useStressOption)THEN |
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ustress(i,j,bi,bj)=tau*(uwind(i,j,bi,bj)-uVel(i,j,1,bi,bj))/u |
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vstress(i,j,bi,bj)=tau*(vwind(i,j,bi,bj)-vVel(i,j,1,bi,bj))/u |
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endif |
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q100=qs+qsr*(dlog(100. _d 0/zoq)-psit(100. _d 0/L)) |
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c |
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return |
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end |
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c |
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c------------------------------------------------------------------ |
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function psiu(zL) |
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c |
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c psiu and psit evaluate stability function for wind speed and scalars |
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c matching Kansas and free convection forms with weighting f |
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c convective form follows Fairall et al (1996) with profile constants |
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c from Grachev et al (2000) BLM |
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c stable form from Beljaars and Holtslag (1991) |
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c |
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implicit none |
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_RL zL,x,y,psik,psic,f,psiu,c |
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if(zL.lt.0.0) then |
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x=(1.-15.*zL)**.25 !Kansas unstable |
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psik=2.*dlog((1.+x)/2.)+dlog((1.+x*x)/2.)-2.*atan(x)+2.*atan(1.) |
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y=(1.-10.15*zL)**.3333 !Convective |
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psic=1.5*dlog((1.+y+y*y)/3.)-sqrt(3.)*atan((1.+2.*y)/sqrt(3.)) |
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& +4.*atan(1.)/sqrt(3.) |
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f=zL*zL/(1.+zL*zL) |
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psiu=(1.-f)*psik+f*psic |
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else |
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c=min(50.,0.35*zL) !Stable |
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psiu=-((1.+1.*zL)**1.+.6667*(zL-14.28)/dexp(c)+8.525) |
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endif |
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return |
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end |
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c-------------------------------------------------------------- |
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function psit(zL) |
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|
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implicit none |
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_RL zL,x,y,psik,psic,f,psit,c |
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if(zL.lt.0.0) then |
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x=(1.-15.*zL)**.5 !Kansas unstable |
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psik=2.*dlog((1.+x)/2.) |
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y=(1.-34.15*zL)**.3333 !Convective |
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psic=1.5*dlog((1.+y+y*y)/3.)-sqrt(3.)*atan((1.+2.*y)/sqrt(3.)) |
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& +4.*atan(1.)/sqrt(3.) |
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f=zL*zL/(1.+zL*zL) |
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psit=(1.-f)*psik+f*psic |
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else |
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c=min(50.,0.35*zL) !Stable |
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psit=-((1.+2.*zL/3.)**1.5+.6667*(zL-14.28)/dexp(c)+8.525) |
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endif |
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return |
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end |
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|
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c------------------------------------------------------------- |
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