Changeset 5470 for LMDZ6/trunk/libf/phylmd/physiq_mod.F90

Timestamp:

Jan 11, 2025, 9:36:52 PM (3 days ago)

Author:

evignon

Message:

raffinement de la condition pour ne pas activer la param d'orographie sous maille
sur les terrains pentus non montagneux tels que les calottes. On raisonne désormais sur un proxy
du nombre de montagnes sous-maille. Travail de Valentin et Etienne

File:

• LMDZ6/trunk/libf/phylmd/physiq_mod.F90 (modified) (6 diffs)

LMDZ6/trunk/libf/phylmd/physiq_mod.F90

@@ -1019 +1019 @@
 
     REAL picefra(klon,klev)
-    REAL zrel_oro(klon)
+    REAL nm_oro(klon)
     !IM cf. AM 081204 END
     !
@@ -4841 +4841 @@
     ! a l'echelle sous-maille:
     !
+
+    ! calculation of nm_oro
+    DO i=1,klon
+          ! nm_oro is a proxy for the number of subgrid scale mountains
+          ! -> condition on nm_oro can deactivate the lifting on tilted planar terrains
+          !    such as ice sheets (work by V. Wiener)
+          ! in such a case, the SSO scheme should activate only where nm_oro>0 i.e. by setting
+          ! nm_oro_t=0.
+          nm_oro(i)=zsig(i)*sqrt(cell_area(i)*(pctsrf(i,is_ter)+pctsrf(i,is_lic)))/(4.*MAX(zstd(i),1.e-8))-1.
+    ENDDO
+
     IF (prt_level .GE.10) THEN
        print *,' call orography ? ', ok_orodr
@@ -4851 +4862 @@
        DO i=1,klon
           itest(i)=0
-          zrel_oro(i)=zstd(i)/(max(zsig(i),1.E-8)*sqrt(cell_area(i)))
-          !zrel_oro: relative mountain height wrt relief explained by mean slope
-          ! -> condition on zrel_oro can deactivate the drag on tilted planar terrains
-          !    such as ice sheets (work by V. Wiener)
           ! zpmm_orodr_t and zstd_orodr_t are activation thresholds set by F. Lott to
           ! earn computation time but they are not physical.
-          IF (((zpic(i)-zmea(i)).GT.zpmm_orodr_t).AND.(zstd(i).GT.zstd_orodr_t).AND.(zrel_oro(i).LE.zrel_oro_t)) THEN
+          IF (((zpic(i)-zmea(i)).GT.zpmm_orodr_t).AND.(zstd(i).GT.zstd_orodr_t).AND.(nm_oro(i).GT.nm_oro_t)) THEN
              itest(i)=1
              igwd=igwd+1
@@ -4906 +4913 @@
        DO i=1,klon
           itest(i)=0
-          !zrel_oro: relative mountain height wrt relief explained by mean slope
-          ! -> condition on zrel_oro can deactivate the lifting on tilted planar terrains
-          !    such as ice sheets (work by V. Wiener)
-          zrel_oro(i)=zstd(i)/(max(zsig(i),1.E-8)*sqrt(cell_area(i)))
-          IF (((zpic(i)-zmea(i)).GT.zpmm_orolf_t).AND.(zrel_oro(i).LE.zrel_oro_t)) THEN
+          IF (((zpic(i)-zmea(i)).GT.zpmm_orolf_t).AND.(nm_oro(i).GT.nm_oro_t)) THEN
              itest(i)=1
              igwd=igwd+1
@@ -5151 +5154 @@
 ! car on peut s'attendre a ce que les petites echelles produisent aussi de la TKE
 ! Mais attention, cela ne va pas dans le sens de la conservation de l'energie!
-          IF ((zstd(i).GT.1.0) .AND.(zrel_oro(i).LE.zrel_oro_t)) THEN
+          IF ((zstd(i).GT.1.0) .AND.(nm_oro(i).GT.nm_oro_t)) THEN
              itest(i)=1
              igwd=igwd+1
@@ -5163 +5166 @@
        DO i=1,klon
           itest(i)=0
-        IF (((zpic(i)-zmea(i)).GT.zpmm_orodr_t).AND.(zstd(i).GT.zstd_orodr_t).AND.(zrel_oro(i).LE.zrel_oro_t)) THEN
+        IF (((zpic(i)-zmea(i)).GT.zpmm_orodr_t).AND.(zstd(i).GT.zstd_orodr_t).AND.(nm_oro(i).GT.nm_oro_t)) THEN
              itest(i)=1
              igwd=igwd+1