WORKING GROUP 4: 3D-VAR Data Assimilation

1. Representatives:

• NCEP: John Derber (lead).
• NCAR: Dale Barker, Yong-Run Guo, Wei Huang, Syed Rizvi, and Qingnong Xiao.
• AFWA/The Aerospace Corporation: Michael McAtee.
• FSL: Stanley Benjamin, Dezso Devenyi.
• CAPS: Jidong Gao, Ming Xue.
• CIMSS/U. of Wisconsin: Bob Aune.

2. Overview of area of focus, objectives and strategies

The WRF data assimilation community is developing 3D- variational (3D-Var) data assimilation tools for the WRF model.  The analysis system must be able to properly resolve all variables and scales of importance of the assimilation system.  This formidable problem will be addressed incrementally by analyzing scales and variables, which we currently know how to do and developing techniques to perform the analysis at smaller scales and with additional analysis variables.

NCAR/MMM develops and supports the WRF Variational Data Assimilation (WRF-Var) System. To find out more about WRF-Var, please visit the WRF-Var web-page (see link below).

2. Links, Documentation

• The WRF-Var Homepage – Learn about the WRF-Var system .
• WRF_Var Tutorial – an introduction to running WRF-Var (Dale Barker).
• Description of Wan-Shu Wu's isotropic but inhomogeneous formulation of background error covariance (cv_options=3) (Wu et al 2002).