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Recent DAS Modifications

GEOS - 5

Several improvements have been made to the GEOS-5 system over the past few months and have been included in the latest upgrade designated 'GEOS-5 V2.0'. The following is a summary of the improvements made for GEOS-5 V2.0:

Updates to the GCM:

1) A bug in cloudnew.F90 related to the use of the wind shear pdf was corrected.

2) Updates were made in cloudnew.F90 to allow a) thicker cold low-level cloud and b) lower limits on RH in re-evaporation.

3) Lowered the upper limit on RADQL and RADQI to 1 g/kg from 40 g/kg.

4) A bug in MOIST was fixed to pressure weight DTDTFRIC.

5) TROPP_THERMAL, TROPP_EPV, and TROPP_BLENDED options were implemented for Tropopause Pressure.

6) The bounds for the relative humidity ramp for mass flux in RAS were changed from [0.6,0.8] to [0.5,0.65].

7) The temperature perturbation in convective boundary layers was capped at 2ºK over the ocean and 4ºK over the landnd.

8) Corrections were made to ALBEDO and SLRSFC calculations in GEOS_SolarGridComp.F90 and sorad.F. The LANDICEALBEDO was changed to 0.775 (from 0.8).

9) The historical CO2 record is used.

10) A gravity wave drag heating correction based on energy conversion from waves (rather than mean flow) was implemented.

11) Modifications were made to thermal capacity of ice to allow diurnal cycle of surface temperature over land and sea ice.

Updates to the Analysis:

1) The satellite bias correction was turned off for AMSU-A channel 14 and SSU channel 3.

2) CRTM coefficients for AMSU and MSU, all channels for NOAA-8 and SSU channels for NOAA-11 were updated.

3) A bug was fixed in the quality control of microwave instruments.

There is also one change to the GEOS-5 file specification document. This change is to correct a documentation error in the unit specification for the RH. In the file spec document, RH in product tavg3d_dyn_v is defined as having units of 'percent'. In fact, RH in this product is provided as a fraction between 0 and 1.

For more details on GEOS-5 data products, please refer to new version of the GEOS-5 File Specification for the GEOS-5.2.0 release. Previous versions of this document are available as well: GEOS-5 File Specification Version 1.0 (The older VERSION 0.1 is retained for your reference.) All the data products are generated at 1/2 degree (lat) by 2/3 degree (lon) horizontal spatial resolution. Click on the following links to view C programs referenced in the Specification: readdata.c and readdata_eos.c

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GMAO Website Curator: Kaushal Patel
Responsible NASA Official: Steven Pawson
Last Modified: 2008-10-29 EDT