G-RSM Output and GRIB format


PWAT (kpds5=54) is precipitable water. The unit is kg/m^2.
In RSM PWAT is written out at two different stages in the code. The two fields should be practically the same. We will remove one of them from the code in the future.

PRATE (kpds5=59) is precipitation rate. The unit is kg/m^2/s. In order to get the total precipitation you have to multiply it by the forecast duration. I don't think total precipitation is a standard output in the current G-RSM.

HGTsfc (kpds5=7) is surface height or topography (m).

Omega: The unit of omega in r_pgb or pgb is Pa/sec. The corresponding code is src/fcst/omega.F (not omegas.F). I also checked that an instantaneous value can be 3~6 Pa/s (100~200 hPa/h) in both GSM and RSM, but in long term average, it converges about appropriate range. In a high resolution experiment, such as 10km, the omega value tends to be very large due to steeper topography. (contributed by Kei)



In order to translate variable names, see:
libs/etc/grib1.kpds5.vsn22
libs/etc/grib1.kpds6.vsn21
These tables are used with libs/etc/grmap .

When using wgrib or grib2ctl, the following table from NCAR is used:
http://dss.ucar.edu/datasets/ds090.0/docs/variablelists/all-vars-file



In order to convert GRIB to netCDF try this tool lats4d:

http://gmao.gsfc.nasa.gov/software/lats4d/



- Comparison of forecasts provided by Sai Ming