Assimilation of UAS Observations from Trident Warrior 2013 into COAMPS NAVDAS

The Trident Warrior 2013 field experiment tested several new observation platforms, including a ScanEagle Unmanned Aerial System (UAS) of off the coast of Norfolk, VA. Seven UAS flights, each of several hours in duration, were launched over the course of four days from the R/V Knorr during July 2014. The ScanEagle UAS collected 1 Hz observations of flight level air temperature, specific humidity, wind speed and direction, and pressure from the surface up to 1500 m ASL which were assimilated into the NRL Atmospheric Variational Data Assimilation System (NAVDAS) in real-time to support Coupled Ocean-Atmosphere Mesoscale Prediction SystemŽ (COAMPS) forecasts. This presentation details the modifications made to NAVDAS to assimilate this data, including the implementation of the observation decoder, changes to the observation thinning method, and implementation of a First Guess at Appropriate Time (FGAT) interpolation routine, as well as the procedures used to quality control the data. Single observation experiments with the UAS data, as well as comparison of analyses with and without the UAS data will also be presented.