FILE FORMAT CONVERSION

(summary of the e-mail exchange within Meteo-France given at the 14th Aladin workshop, Innsbruck by Maria Derkova)

FORMAT: FA vs. GRIB vs. NETCDF

volumetry is an essential point

compacting facilities needed for:

storage

I/O (memory/disc access)

exchange of real-time data (mesoNH: 64 bits/value, ARPEGE/ALADIN 16/18 bits/value)

NETCDF:

no compacting

no I/O control => pb on parallel platforms

easy to use (USA, ECMWF demeter project - but not for storage)

GRIB:

generally OK

but not unified enough (parameter ID center dependent)

FA:

not perfect

but widely used in our community

"portable"

compacting possible

convertors to other formats shall be developed

maintenance issue to be considered

link with HIRLAM cooperation to be kept in minds

EXTERNALISED SURFACE SCHEME

two output files - upper air (FA)

- surface (LFI)

difficult to handle in operational practice, but probably possible to merge

problem of the ascending compactibility with ALADIN !

content of the file to be archived can be revisited

what to do with fields which are not reals ?

PROGRID (GRIBEUSE)

MF operational sequence reads:

historical FA files -> lat/lon fullpos -> progrid -> BDAP, SYNERGY

shall fullpos and progrid be merged to avoid duplication of the work in case of new fields in Arome ?

progrid has been recently improved: documented grib and usage of gribex(including the dolby technique of ecmwf) is now possible

2004-07-15T13:14:32