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Overview

AIRS

The effectiveness of the assimilation of moisture channels from AIRS will be investigated using the GEOS-5 data assimilation system. A new transmittance algorithm that is included in beta-test mode in the JCSDA Community Radiative Transfer Model (CRTM) that is included with the GSI will be tested. This new transmittance algorithm is expected to improve the AIRS assimilation. The tests will compare the results using the current algorithm with those using the new algorithm.

The assessment metrics will be the root mean square of the innovations (i.e., the observations minus the GEOS-5 background from a 3-9-hour forecast from the previous meteorological analysis); the anomaly correlation score for the 5-day forecast of the 500 hPa height over the Northern and Southern Hemispheres; and the impact (reduction in error in a 24-hour forecast) on a global energy norm that is available through the current GEOS-5 software.

MLS

As a step toward assimilating MLS radiance data in the GSI analysis, we will couple the JPL MLS software into the GMAO.s GSI software. The JPL MLS software is the forward model in the MLS Level 2 software that has to be coupled with the GEOS-5 observation operator to calculate a synthetic brightness temperature from the model using the JPL software. This synthetic observation has to be compared with the MLS satellite brightness temperature in order to calculate the innovation (i.e., the difference between the observation and the model forecast satellite brightness temperature). The correctness of the implementation will be tested by calculation of innovations and comparing the statistics of the innovations with those from other radiance data in the upper troposphere.

Progress and Results

  August 2010

  April 2010

  AIRS September 2010 Final Report

  MLS September 2010 Final Report

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