PDF《GEOS–CHEM:》

will be added in v7C01C02 ? Nested grid does not yet work with GEOSC4 ? New TPCORE has yet to be modified for boundary conditions ? Also, GEOSC4 horizontal grid is

1 x 1.25, not

1 x

1 06 October

2004 GEOS-CHEM: The Agony and the Ecstacy

12 Transition to GEOSC4 Differences in CLOUD CONVECTION ? GEOSC4 cloud convection fields are totally different ? GEOSC3 style CLDMAS and DTRAIN are no longer provided ? GEOSC4 uses the NCAR convection scheme (cf. P Rasch) ? Hack (shallow) convection: HKETA, HKBETA ? Zhang/McFarlane (deep) convection: ZMMU, ZMMD, ZMEU ? Scheme includes both updrafts &

downdrafts ? New GEOSC4 met fields required new convection code ? Convection code had to be stripped out of MATCH model ? We also had to re-install the wet scavenging in cloud updrafts ? Almost all of this work was done by Shiliang Wu

06 October

2004 GEOS-CHEM: The Agony and the Ecstacy

13 Transition to GEOSC4 Differences between GEOSC4 and GEOSC4 ? To complicate matters, there were

2 versions of GEOSC4 ? Version 3: (GMAO: 1.3 r7) was made from

2002 thru Jan

2004 ? Version 4: (GMAO: 1.4 r2) was introduced in Jan

2004 ? GMAO says V4 contains improvements over V3: ? New Land Model ? Improvements to Skin Temperature analysis ? NOAA-17 satellite assimilation ? MODIS cloud track winds assimilation over the poles ? Relative Humidity fix near surface ? Diag wind output stream for stratospheric transport customers http://gmao.gsfc.nasa.gov/operations/recent_mods.php

06 October

2004 GEOS-CHEM: The Agony and the Ecstacy

14 Transition to GEOSC4 Differences between GEOSC4 and GEOSC4 ? An annoyance: the averaging periods for certain fields were different in GEOSC4 V4 than in GEOSC4 V3 ? In GEOSC4 v4, the averaging periods for A6 fields are the same as in the GEOSC1, GEOSCSTRAT, and GEOSC3 ? In GEOSC4 v3, the averaging periods for the A6 fields are shifted

3 hours later than V4. ? A6 fields = 6-hour average fields. ........