Assimilation of Surface Meteorological Observations in COAMPS NAVDAS and COAMPS-AR

Conventional meteorological surface stations typically offer complete observations of temperature, dew point, winds, and pressure with high temporal frequency within the planetary boundary layer. The density of these stations continues to increase, as government agencies, private businesses, and individuals deploy new and expand existing mesonets. Assimilating these observations into the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPSŪ) NRL Atmospheric Variational Data Assimilation System (NAVDAS; 3DVar system) has shown statistically significant positive impact to forecasts of 2-m air temperature and 2-m dewpoint temperature out to lead times of 12 hours in data withholding tests. This presentation will highlight results of these tests using the 3DVar system, as well as compare impacts of these observations on NRL's 4DVar system as well (COAMPS-Accelerated Representer [AR]). Impact of these observations will be measured using data withholding and adjoint sensitivity tests.