9.6    DTC Data Assimilation System Community Support and Testing Activities: Variational, Ensemble and Hybrid

Shao, Hui, National Center for Atmospheric Research, M. Hu, NOAA/ESRL, D. Stark, K. Newman, C. Zhou, X. Y. Huang, NCAR, John Derber, and Michael Lueken, NCEP/EMC

The Developmental Testbed Center (DTC) is a distributed facility to serve as a bridge between research and operations and facilitate the activities of the Numerical Weather Prediction (NWP) community. Over past three years, the DTC has been supporting the Gridpoint Statistical Interpolation (GSI) data assimilation (DA) system for the research community. The DTC has released three versions of the community GSI system and hosted two GSI tutorials and one GSI workshop in Boulder, CO. The DTC provides community support through the DTC GSI webpage and GSI helpdesk. In addition to providing a community resource, the DTC also serves as a bridge among several development groups. For this purpose, the DTC created and maintains the community GSI repository and organizes the GSI review committee.

The DTC is also testing and evaluating DA techniques and systems primarily in regional applications. In addition to testing GSI, the DTC is expanding its horizons to advanced assimilation techniques and systems, including ensemble Kalman Filter (EnKF) and GSI based hybrid variational-ensemble (GSI-Hybrid) data assimilation systems. The DTC staff started collaboration with code developers to investigate and test candidate systems to be supported in the future.

This paper will introduce the ongoing DTC data assimilation community efforts on these various techniques and systems, their current status, and future plans. Some preliminary testing and evaluation results will be presented as well.