[Wrf-users] RADT and nesting in WRF ARW

[Eric Altshuler]

Hello,

When running a nested simulation in WRF ARW, is it better to use one value of RADT (number of minutes between radiation calls) for all domains, or should each domain have its own value of RADT according to its horizontal resolution? For example, if I have the following domain configuration:

Domain 1 (coarse mesh) 36km
Domain 2 (parent is domain 1) 12km
Domain 3 (parent is domain 2) 4km

should the RADT setting in namelist.input be:

RADT = 36, 36, 36

or should it be:

RADT = 36, 12, 4

The various WRF docs give conflicting information on what the proper setting of RADT is in the case of nested simulations.

Any comments would be appreciated.

Best regards,

Eric L. Altshuler
Assistant Research Scientist
Center for Ocean-Land-Atmosphere Studies
4041 Powder Mill Road, Suite 302
Calverton, MD 20705-3106
USA

E-mail: ela at cola.iges.org
Phone: (301) 902-1257
Fax: (301) 595-9793