Tuesday 15h April 2006, 11.00 AM
Laboratoire de Météorologie Dynamique / Jussieu
Meeting room nr. 313, corridor 45-55, 3rd floor
4 place de Jussieu
75252 PARIS CEDEX 05

Seminar: Data Assimilation at NRL
by Benjamin RUSTON, Naval Research Laboratory, Monterey

Abstract

The Naval Research Laboratory Marine Meteorology Division in Monterey California is responsible for development and research into the Navy Operational Global Atmospheric Prediction System (NOGAPS) and Coupled Ocean Atmosphere Prediction System (COAMPS) forecasting systems. The data assimilation section utilizes the currently operational NRL Atmospheric Variational Data Assimilation System (NAVDAS), a three-dimensional system, and has begun testing the forecast impacts of radiances using the four-dimensional NAVDAS-AR. New developments in the system include the addition of winds and TPW from WindSat and SSMIS, and QuikScat scatterometer wind vectors. The presentation will focus on the ongoing research which includes assimilation of SSMIS, AIRS, and the ATOVS suite over land. The calibration anomalies of the SSMIS have been largely identified and either mitigated or flagged in the latest pre-processor developed jointly by NRL and the Met Office. The AIRS assimilation experiments have included analysis provided by the adjoints of NOGAPS and NAVDAS, which are used to find the gradient of the forecast error cost function with respect to the observation vector. This allows observation sensitivity for each channel to be found, and has been a helpful tool in channel selection and quality control. Lastly, a combined microwave/infrared one-dimensional preprocessor has been developed for the ATOVS suite which provides estimates of the land surface temperature and spectral emissivity for the three-dimensional system. This work has also led to collaboration and intercomparison between methods and databases. To close there will be an introductory look into an NWP-SAF project providing information and web links to sources of emissivity information suitable for input to RTTOV, both in the IR and MW.

For more information: B. RUSTON (B. Ruston email)

Link to presentation: to be added

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