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module cdrag_m |
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|
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IMPLICIT NONE |
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|
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contains |
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|
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SUBROUTINE cdrag(nsrf, speed, t, q, zgeop, psol, ts, qsurf, rugos, pcfm, & |
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pcfh, pref) |
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|
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! From LMDZ4/libf/phylmd/clcdrag.F90 and |
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! LMDZ4/libf/phylmd/coefcdrag.F90, version 1.1.1.1, 2004/05/19 |
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! 12:53:07 |
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|
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! Objet : calcul des drag coefficients au sol pour le moment et |
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! les flux de chaleur sensible et latente et calcul de la pression |
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! au niveau de reference. |
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|
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! I. Musat, 01 Jul 2002 |
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|
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use clesphys, only: f_cdrag_oce, f_cdrag_ter |
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use indicesol, only: is_oce |
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use nr_util, only: assert_eq |
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use SUPHEC_M, only: rcpd, rd, retv, rg |
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USE yoethf_m, ONLY: rvtmp2 |
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|
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INTEGER, intent(in):: nsrf ! indice pour le type de surface |
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|
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REAL, intent(in):: speed(:) ! (knon) |
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! norm of the wind at the first model level |
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|
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REAL, intent(in):: t(:) ! (knon) |
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! temperature de l'air au 1er niveau du modele |
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|
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REAL, intent(in):: q(:) ! (knon) ! humidite de l'air au 1er niveau du modele |
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|
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REAL, intent(in):: zgeop(:) ! (knon) |
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! g\'eopotentiel au 1er niveau du mod\`ele |
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|
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REAL, intent(in) :: psol(:) ! (knon) pression au sol |
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REAL, intent(in):: ts(:) ! (knon) temperature de l'air a la surface |
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REAL, intent(in):: qsurf(:) ! (knon) humidite de l'air a la surface |
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REAL, intent(in):: rugos(:) ! (knon) rugosit\'e |
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REAL, intent(out):: pcfm(:) ! (knon) drag coefficient pour le moment |
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|
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REAL, intent(out):: pcfh(:) ! (knon) |
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! drag coefficient pour les flux de chaleur latente et sensible |
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|
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REAL, intent(out), optional:: pref(:) ! (knon) pression au niveau zgeop/RG |
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|
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! Local: |
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REAL, PARAMETER:: ckap=0.40, cb=5.0, cc=5.0, cd=5.0, cepdu2=0.1**2 |
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INTEGER i, knon |
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REAL zdu2, ztsolv, ztvd, zscf, zucf, zcr, friv, frih |
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REAL zcfm1, zcfh1, zcfm2, zcfh2 |
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real zcdn ! drag coefficient neutre |
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|
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REAL zri |
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! nb. Richardson entre la surface et la couche zgeop/RG |
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! nombre de Richardson entre la surface et le niveau de reference (zri) |
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|
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!------------------------------------------------------------------------- |
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|
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knon = assert_eq([size(speed), size(t), size(q), size(zgeop), size(ts), & |
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size(qsurf), size(rugos), size(pcfm), size(pcfh), size(pcfm)], & |
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"cdrag knon") |
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|
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DO i = 1, knon |
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zdu2 = max(cepdu2, speed(i)**2) |
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ztsolv = ts(i) * (1. + RETV * max(qsurf(i), 0.)) |
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ztvd = (t(i)+zgeop(i)/RCPD/(1.+RVTMP2*q(i))) *(1.+RETV*q(i)) |
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zri = zgeop(i)*(ztvd-ztsolv)/(zdu2*ztvd) |
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zcdn = (ckap/log(1.+zgeop(i)/(RG*rugos(i))))**2 |
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|
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IF (zri > 0.) THEN |
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! Situation stable. Pour eviter les inconsistances dans les cas |
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! tres stables on limite zri a 20. cf Hess et al. (1995). |
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zri = min(20., zri) |
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zscf = SQRT(1.+cd*ABS(zri)) |
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friv = max(1. / (1.+2.*CB*zri/ zscf), 0.1) |
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zcfm1 = zcdn * friv |
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frih = max(1./ (1.+3.*CB*zri*zscf), 0.1) |
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zcfh1 = f_cdrag_ter * zcdn * frih |
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IF (nsrf == is_oce) zcfh1 = f_cdrag_oce * zcdn * frih |
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pcfm(i) = zcfm1 |
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pcfh(i) = zcfh1 |
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ELSE |
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! situation instable |
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zucf = 1./(1.+3.0*cb*cc*zcdn*SQRT(ABS(zri) & |
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*(1.0+zgeop(i)/(RG*rugos(i))))) |
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zcfm2 = zcdn*max((1.-2.0*cb*zri*zucf), 0.1) |
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zcfh2 = f_cdrag_ter * zcdn*max((1.-3.0*cb*zri*zucf), 0.1) |
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pcfm(i) = zcfm2 |
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pcfh(i) = zcfh2 |
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|
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! pcfh sur l'ocean cf. Miller et al. (1992) |
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zcr = (0.0016/(zcdn*SQRT(zdu2)))*ABS(ztvd-ztsolv)**(1./3.) |
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IF (nsrf == is_oce) pcfh(i) = f_cdrag_oce * zcdn & |
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* (1. + zcr**1.25)**(1. / 1.25) |
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ENDIF |
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END DO |
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|
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if (present(pref)) & |
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pref = exp(log(psol) - zgeop / (RD * t * (1. + RETV * max(q, 0.)))) |
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|
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END SUBROUTINE cdrag |
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|
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end module cdrag_m |