A study of data selection and quality control and their impact in the North Pacific

The Navy Operational Global Atmospheric Prediction System (NOGAPS) has at times suffered from relatively large forecast errors over North America that can be traced back to analysis errors in sensitive areas of the atmosphere over the North Pacific. Under these conditions, even very small analysis errors rapidly amplify and expand. Although the exact cause of these errors is unknown, this research will investigate the possible role of the data quality control and selection procedures in minimizing these errors. In particular, the satellite wind and aircraft data will be examined for their possible contribution to analysis errors in the North Pacific region. The newly developed Naval Atmospheric Variational Data Assimilation System (NAVDAS) will be the vehicle to study specific cases identified as highly sensitive by the NOGAPS singular vector diagnostics. In the data assimilation system, the analysis is performed using a three-dimensional variational analysis coupled to NOGAPS, a global spectral model. Much of the data assimilation system is dedicated to the processing, display, and quality control of the various data. A brief overview of the newly developed system and some validation results will be included in this presentation.