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MARS storage issues. Pedro Viterbo European Centre for Medium-Range Weather Forecasts. ELDAS 2 nd Progress Meeting INM, Madrid, 10-11.12.2003. GRIB for MARS archive. General remarks: New Class for ELDAS: Number 8 , Mars mnemonic ‘el’ Different experiment versions identified by EXPVER
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MARS storage issues Pedro Viterbo European Centre for Medium-Range Weather Forecasts ELDAS 2nd Progress Meeting INM, Madrid, 10-11.12.2003
GRIB for MARS archive • General remarks: • New Class for ELDAS: Number 8, Mars mnemonic ‘el’ • Different experiment versions identified by EXPVER final version (EXPVER=1) • Different productions of the same variable (e.g. soil moisture, precipitation) identified by ‘’STREAM’’ • Forcing fields produced outside ECMWF: • TYPE=34 (‘’gridded observations’’) • Data should be saved from N S and W E • Parameter numbers: Code table 128, plus new code table (specific to ELDAS) • Grid 0.2 x 0.2 (or multiplies of it), ELDAS orography • Data producer should: • provide sample routines to read the data • provide data grib coded via ftp fine tuning of grib code (i.e. header changes) can be performed before putting the data into MARS
Precipitation in Mars • Streams (parameter number= 228): • Daily fields (06UTC- 06UTC) derived from gauge data • Daily fields (06UTC- 06UTC) derived from gauge + radar data • Daily precipitation errors ( filled with 24h forecasts) (TYPE=13) • 3-hourly disaggregated fields (based on forecast) • SW+LW radiation: • Bit-mapped • Parameter number: SW:169, LW:175 • 3-hourly
Other forcing fields • Heating rates: • Strange fields for MARS: • Suggestion to store 4 fields: • Delta T • flag • Initial time UTC (HHMM) • Final time UTC (HHMM) • Meteorological background field from ECMWF: • 2T, 2Q/RH, 10U/V, advection , … • 2m-T interpolated and adjusted via lapse-rate to ELDAS orography • 2m-RH no adjustment • Based on t511/60 level data from 12-36 hour forecasts from 12 UTC: • 30 Sep 1999 – 31 Aug 2000: Starting from ERA40 159/60 level initial conditions • 1 Sep 2000 – 19 Nov 2000: 12-36 hour from t511 esuite • 20 Nov 2000 – 31 Dec 2000: Operations • All forecasts with 3-hourly post-processing, to disaggregate precipitation • Spherical harmonics data projected to reduced gaussian grid and then interpolated to 0.2 deg • Based on ECMWF orography
Production output fields • Production output fields from outside ECMWF: • Data source identifier: originating centre • Sub-centre identifier: 98 (ECMWF) • 0.2 x 0.2 grid
Archival for DWD • MARS will NOT archive fields in two representations (rotated lat-lon and lat-lon) • Two possibilities • Archive rotated • DWD will be able to reuse the data in a straightforward manner + • Anyone else will have to go through a transformation to get lat-lon - • MARS utility for re-projection to be developed - • Archive lat-lon • DWD will have to rotate (and rotate/un-rotate will not get back original field) - • (DWD could separately store rotated initial fields in, e.g., ecfs) • Anyone else will use the data directly + • MARS utility to rotate to be developed (?) -