3.1
Building the next generation global atmospheric data assimilation system at the National Centers for Environmental Prediction
Stephen Lord, NOAA/NWS/NCEP/EMC, Camp Springs, MD; and J. C. Derber and Z. Toth
The National Centers for Environmental Prediction, Environmental Modeling Center (NCEP/EMC) is constructing its Next-Generation Atmospheric Data Assimilation System (NGADAS). To gain maximum flexibility, and ensure that continuous progress is made over the multi-year lifetime of this project, EMC has adopted a strategy consisting of three closely related efforts. The first effort is to continue an evolutionary path based on the successful Spectral Statistical Interpolation (SSI) system which has been continually improved in operations over the past 15 years. A new analysis code, the Gridpoint Statistical Interpolation (GSI) system, has been developed by EMC over the past 3 years and has several advantages, making it a powerful and flexible candidate for the NGADAS. Moreover, it is applicable to both global and regional domains, thereby achieving one of the strategic goals of the NGADAS. The second effort, in collaboration with NASA's Global Modeling and Analysis Office (GMAO) consists of a 4-Dimensional Variational (4DVAR) approach, which incorporates the GSI as a fundamental component. Since the GSI is common between the EMC and GMAO efforts, considerable planning and collaboration have produced a viable code management strategy across the participating organizations, thereby achieving a second strategic goal of providing a community-wide support. The third effort, in collaboration with investigators from THe Observing system Research and Predictability EXperiment (THORPEX), is to develop and test an Ensemble Data Assimilation (EnsDA) system using NCEP's global forecast model. EnsDA systems are relatively new but early results have been very encouraging. Progress and schedule for the NGADAS project will be discussed. .
Session 3, Assimilation of Observations (Ocean, Atmosphere, and Land Surface) into Models
Tuesday, 16 January 2007, 8:30 AM-4:00 PM, 212B
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