Regionally Enhanced Global (REG) 4D-Var
Abstract
A regionally enhanced global (REG) data assimilation (DA) method is proposed. The technique blends high-resolution model information from a single or multiple limited-area model domains with global model and observational information to create a regionally enhanced analysis of the global atmospheric state. This single analysis provides initial conditions for both the global and limited-area model forecasts. The potential benefits of the approach for operational data assimilation are (i) reduced development cost, (ii) reduced overall computational cost, (iii) improved limited-area forecast performance from the use of global information about the atmospheric flow, and (iv) improved global forecast performance from the use of more accurate model information in the limited-area domains. The method is tested by an implementation on the U.S. Navy’s four-dimensional variational global data assimilation system and global and limited-area numerical weather prediction models. The results of the monthlong forecast experiments suggest that the REG DA approach has the potential to deliver the desired benefits.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 14, 2018
- Source ID
- 10.1175/mwr-d-17-0228.1
Entities
People
- Adam Brainard
- Craig H Bishop
- David D. Kuhl
- István Szunyogh
- Karl Hoppel
- Michael A. Herrera
- Qingyun Zhao
- Sabrina Rainwater
- Teddy R. Holt
Organizations
- National Academies of Sciences, Engineering, and Medicine
- Office of Naval Research Global
- Texas A&M University
- United States Naval Research Laboratory