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module soil_m |
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IMPLICIT NONE |
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contains |
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SUBROUTINE soil(dtime, nisurf, knon, snow, tsurf, tsoil, soilcap, soilflux) |
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|
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! From LMDZ4/libf/phylmd/soil.F, version 1.1.1.1 2004/05/19 |
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|
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! Author: Frederic Hourdin 30/01/92 |
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|
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! Object: computation of the soil temperature evolution, the |
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! surfacic heat capacity "Soilcap" and the surface conduction flux |
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|
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! Method: implicit time integration |
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|
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! Consecutive ground temperatures are related by: |
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! T(k+1) = C(k) + D(k)*T(k) (1) |
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! the coefficients C and D are computed at the t-dt time-step. |
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! Routine structure: |
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! 1) new temperatures are computed using (1) |
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! 2) C and D coefficients are computed from the new temperature |
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! profile for the t+dt time-step |
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! 3) the coefficients A and B are computed where the diffusive |
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! fluxes at the t+dt time-step is given by |
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! Fdiff = A + B Ts(t+dt) |
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! or Fdiff = F0 + Soilcap (Ts(t+dt)-Ts(t))/dt |
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! with F0 = A + B (Ts(t)) |
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! Soilcap = B*dt |
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|
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USE dimens_m, only: |
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USE indicesol |
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USE dimphy |
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USE dimsoil |
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USE suphec_m |
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|
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! Interface: |
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! ---------- |
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|
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! Arguments: |
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! ---------- |
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! dtime physical timestep (s) |
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! indice sub-surface index |
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! snow(klon, nbsrf) snow |
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! tsurf(knon) surface temperature at time-step t (K) |
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! tsoil(klon, nsoilmx) temperature inside the ground (K) |
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! soilcap(klon) surfacic specific heat (W*m-2*s*K-1) |
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! soilflux(klon) surface diffusive flux from ground (Wm-2) |
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|
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! declarations: |
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! ------------- |
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|
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! ----------------------------------------------------------------------- |
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! arguments |
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! --------- |
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|
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REAL dtime |
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INTEGER nisurf, knon |
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REAL tsurf(knon), tsoil(klon, nsoilmx), snow(klon) |
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REAL soilcap(klon), soilflux(klon) |
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|
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! ----------------------------------------------------------------------- |
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! local arrays |
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! ------------ |
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|
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INTEGER ig, jk |
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! $$$ REAL zdz2(nsoilmx), z1(klon) |
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REAL zdz2(nsoilmx), z1(klon, nbsrf) |
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REAL min_period, dalph_soil |
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REAL ztherm_i(klon) |
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|
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! local saved variables: |
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! ---------------------- |
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REAL dz1(nsoilmx), dz2(nsoilmx) |
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! $$$ REAL zc(klon, nsoilmx), zd(klon, nsoilmx) |
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REAL zc(klon, nsoilmx, nbsrf), zd(klon, nsoilmx, nbsrf) |
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REAL lambda |
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SAVE dz1, dz2, zc, zd, lambda |
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LOGICAL firstsurf(nbsrf) |
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SAVE firstsurf |
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REAL isol, isno, iice |
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SAVE isol, isno, iice |
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|
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DATA firstsurf/.TRUE., .TRUE., .TRUE., .TRUE./ |
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|
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DATA isol, isno, iice/2000., 2000., 2000./ |
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|
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! ----------------------------------------------------------------------- |
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! Depthts: |
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! -------- |
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|
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REAL rk, fz1, rk1, rk2 |
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|
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soilflux(:) = 0. |
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! calcul de l'inertie thermique a partir de la variable rnat. |
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! on initialise a iice meme au-dessus d'un point de mer au cas |
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! ou le point de mer devienne point de glace au pas suivant |
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! on corrige si on a un point de terre avec ou sans glace |
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|
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IF (nisurf==is_sic) THEN |
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DO ig = 1, knon |
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ztherm_i(ig) = iice |
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IF (snow(ig)>0.0) ztherm_i(ig) = isno |
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END DO |
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ELSE IF (nisurf==is_lic) THEN |
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DO ig = 1, knon |
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ztherm_i(ig) = iice |
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IF (snow(ig)>0.0) ztherm_i(ig) = isno |
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END DO |
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ELSE IF (nisurf==is_ter) THEN |
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DO ig = 1, knon |
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ztherm_i(ig) = isol |
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IF (snow(ig)>0.0) ztherm_i(ig) = isno |
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END DO |
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ELSE IF (nisurf==is_oce) THEN |
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DO ig = 1, knon |
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ztherm_i(ig) = iice |
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END DO |
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ELSE |
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PRINT *, 'valeur d indice non prevue', nisurf |
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STOP 1 |
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END IF |
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|
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IF (firstsurf(nisurf)) THEN |
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|
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! ----------------------------------------------------------------------- |
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! ground levels |
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! grnd=z/l where l is the skin depth of the diurnal cycle: |
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! -------------------------------------------------------- |
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|
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min_period = 1800. ! en secondes |
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dalph_soil = 2. ! rapport entre les epaisseurs de 2 couches succ. |
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|
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OPEN (99, FILE='soil.def', STATUS='old', FORM='formatted', ERR=9999) |
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READ (99, *) min_period |
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READ (99, *) dalph_soil |
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PRINT *, 'Discretization for the soil model' |
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PRINT *, 'First level e-folding depth', min_period, ' dalph', & |
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dalph_soil |
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CLOSE (99) |
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9999 CONTINUE |
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|
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! la premiere couche represente un dixieme de cycle diurne |
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fz1 = sqrt(min_period/3.14) |
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|
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DO jk = 1, nsoilmx |
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rk1 = jk |
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rk2 = jk - 1 |
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dz2(jk) = fz(rk1) - fz(rk2) |
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END DO |
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DO jk = 1, nsoilmx - 1 |
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rk1 = jk + .5 |
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rk2 = jk - .5 |
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dz1(jk) = 1./(fz(rk1)-fz(rk2)) |
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END DO |
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lambda = fz(.5)*dz1(1) |
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PRINT *, 'full layers, intermediate layers (seconds)' |
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DO jk = 1, nsoilmx |
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rk = jk |
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rk1 = jk + .5 |
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rk2 = jk - .5 |
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PRINT *, 'fz=', fz(rk1)*fz(rk2)*3.14, fz(rk)*fz(rk)*3.14 |
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END DO |
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! PB |
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firstsurf(nisurf) = .FALSE. |
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|
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! Initialisations: |
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! ---------------- |
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|
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ELSE |
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! ----------------------------------------------------------------------- |
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! Computation of the soil temperatures using the Cgrd and Dgrd |
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! coefficient computed at the previous time-step: |
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! ----------------------------------------------- |
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|
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! surface temperature |
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DO ig = 1, knon |
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tsoil(ig, 1) = (lambda*zc(ig, 1, nisurf)+tsurf(ig))/(lambda*(1.-zd(ig, 1, & |
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nisurf))+1.) |
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END DO |
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|
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! other temperatures |
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DO jk = 1, nsoilmx - 1 |
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DO ig = 1, knon |
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tsoil(ig, jk+1) = zc(ig, jk, nisurf) + zd(ig, jk, nisurf)*tsoil(ig, & |
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jk) |
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END DO |
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END DO |
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|
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END IF |
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! ----------------------------------------------------------------------- |
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! Computation of the Cgrd and Dgrd coefficient for the next step: |
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! --------------------------------------------------------------- |
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|
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! $$$ PB ajout pour cas glace de mer |
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IF (nisurf==is_sic) THEN |
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DO ig = 1, knon |
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tsoil(ig, nsoilmx) = rtt - 1.8 |
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END DO |
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END IF |
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|
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DO jk = 1, nsoilmx |
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zdz2(jk) = dz2(jk)/dtime |
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END DO |
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|
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DO ig = 1, knon |
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z1(ig, nisurf) = zdz2(nsoilmx) + dz1(nsoilmx-1) |
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zc(ig, nsoilmx-1, nisurf) = zdz2(nsoilmx)*tsoil(ig, nsoilmx)/ & |
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z1(ig, nisurf) |
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zd(ig, nsoilmx-1, nisurf) = dz1(nsoilmx-1)/z1(ig, nisurf) |
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END DO |
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|
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DO jk = nsoilmx - 1, 2, -1 |
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DO ig = 1, knon |
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z1(ig, nisurf) = 1./(zdz2(jk)+dz1(jk-1)+dz1(jk)*(1.-zd(ig, jk, nisurf))) |
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zc(ig, jk-1, nisurf) = (tsoil(ig, jk)*zdz2(jk)+dz1(jk)*zc(ig, jk, nisurf) & |
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)*z1(ig, nisurf) |
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zd(ig, jk-1, nisurf) = dz1(jk-1)*z1(ig, nisurf) |
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END DO |
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END DO |
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|
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! ----------------------------------------------------------------------- |
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! computation of the surface diffusive flux from ground and |
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! calorific capacity of the ground: |
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! --------------------------------- |
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|
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DO ig = 1, knon |
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soilflux(ig) = ztherm_i(ig)*dz1(1)*(zc(ig, 1, nisurf)+(zd(ig, 1, & |
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nisurf)-1.)*tsoil(ig, 1)) |
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soilcap(ig) = ztherm_i(ig)*(dz2(1)+dtime*(1.-zd(ig, 1, nisurf))*dz1(1)) |
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z1(ig, nisurf) = lambda*(1.-zd(ig, 1, nisurf)) + 1. |
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soilcap(ig) = soilcap(ig)/z1(ig, nisurf) |
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soilflux(ig) = soilflux(ig) + soilcap(ig)*(tsoil(ig, 1)*z1(ig, nisurf)- & |
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lambda*zc(ig, 1, nisurf)-tsurf(ig))/dtime |
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END DO |
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|
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contains |
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|
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real function fz(rk) |
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real rk |
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fz = fz1*(dalph_soil**rk-1.)/(dalph_soil-1.) |
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end function fz |
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END SUBROUTINE soil |
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end module soil_m |