A multiscale four-dimensional data assimilation system applied in the San Joaquin Valley during SARMAP. Part I: modeling design and basic performance characteristics

This paper presents results of numerical simulations made with a high-resolution multiscale four-dimensional data assimilation system applied over California during two episodes associated with high ozone concentrations in the San Joaquin Valley. The model used here is the nonhydrostatic Pennsylvania State University - National Center for Atmospheric Research Mesoscale Model (MM5). The focus of the paper is the objective validation of the regional (mesoalpha scale) meteorological results. The multiscale data assimilation approach produces highly reliable simulations of the wind, temperature, mixed-layer depth, and moisture, each of which is vital to air quality modeling and a host of other mesoscale applications. -from Authors