Major bug fix for tendencies from NSAS cumulus scheme #71
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…n variables) are wrong as they are divided by dt*stepcu instead of dt. nsas2d and nscv2d are called with dt. As the tendency terms are kept constant during stepcu time steps, they should not be divided by dt*stepcu but by dt. stepcu is defined in phys/module_physics_init.F by: STEPCU = nint(CUDT*60./DT) STEPCU = max(STEPCU,1) The user verified this by playing with time_step and cudt. Any reasonable value of time_step and cudt gives very similar results as soon as stepcu = 1, but results drastically change when stepcu = 2 or higher values.
mkavulich
approved these changes
Dec 16, 2016
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TYPE: bug fix
KEYWORDS: NSAS cumulus scheme, tendencies
SOURCE: Sebastien Masson, LOCEAN - IPSL, Univ. Pierre et Marie Curie, France
DESCRIPTION OF CHANGES:
In module_cu_nsas.F, all cumulus tendency terms (*cuten variables) are wrong as they are divided by dt*stepcu (where stepcu is the number of time steps in CUDT) instead of dt while the deep (nsas2d) and shallow (nscv2d) routines are called with dt. As tendency terms are kept constant during stepcu time steps, they should not be divided by dt*stepcu but by dt.
LIST OF MODIFIED FILES:
phys/module_cu_nsas.F
TESTS CONDUCTED: reg tested. Ran January case, new changes provide more heating and less rainfall. The user verified this by playing with time_step and cudt. Any reasonable value of time_step and cudt gives very similar results when stepcu = 1, but results drastically change when stepcu = 2 or higher values.