Radiative transfer schemes : Différence entre versions

Version du 24 avril 2023 à 12:50

There are different radiative schemes that can be used in LMDZ:

the "legacy" (oldest) radiative scheme: available regardless of the makelmdz options used. May be selected using the iflag_rrtm=0 option in physiq.def. Note that this schemes also requires using 2 bands in the SW (Short Wave, i.e. visible wavelengths), i.e. setting NSW=2 in physiq.def
RRTM, selected with iflag_rrtm=1 (and requiring that NSW=6), which is available if the GCM has been compiled with the -rad rrtm option (see WhatIs: The makelmdz fcm script).
ECRAD (implementation is ongoing at the time of writing this) , selected with iflag_rrtm=2, which is available if the GCM has been compiled with the -rad ecrad option.

ECRad has three sub-options for the treatment of clouds:

McICA : Monte Carlo Independent Column Approximation. Assez rapide, comme si on faisait des sondages, on tire une dizaine de sous-colonnes.
triple cloud : trois colonnes par maille : ciel clair, nuageux compact, nuageux intermédiraire. Le plus proche de RRTM.
triple cloud avec Spartacus : effet 3D des nuages, multiplie par 5 le temps d'exécution du rayonnement.

ECRad also has two sub-options for the treatment of the gas phase:

@@ Ligne 1 : / Ligne 1 : @@
 There are different radiative schemes that can be used in LMDZ:
-* the "legacy" (oldest) radiative scheme: always available. May be selected using the '''iflag_rrtm=0''' option in physiq.def. Note that this schemes also requires using 2 bands in the SW (Short Wave, i.e. visible wavelengths), i.e. setting '''NSW=2''' in physiq.def
+* the "legacy" (oldest) radiative scheme: available regardless of the makelmdz options used. May be selected using the '''iflag_rrtm=0''' option in physiq.def. Note that this schemes also requires using 2 bands in the SW (Short Wave, i.e. visible wavelengths), i.e. setting '''NSW=2''' in physiq.def
 * RRTM, selected with '''iflag_rrtm=1''' (and requiring that '''NSW=6'''), which is available if the GCM has been compiled with the '''-rad rrtm''' option (see  [[WhatIs: The makelmdz fcm script]]).
 * ECRAD (implementation is ongoing at the time of writing this) , selected with '''iflag_rrtm=2''', which is available if the GCM has been compiled with the '''-rad ecrad''' option.