Use of Global Hawk Observations in Combination with Satellite Observations for Optimal Tropical Cyclone Analyses and Forecasts

Sensing Hazards with Operational Unmanned Technology (SHOUT) is a NOAA multi-year program to deploy the unmanned Global Hawk (GH) aircraft to observe high-impact weather and mitigate potential future gaps in satellite observations. The GH aircraft is equipped with GPS dropswindsondes and a suite of remote sensing instruments that are capable of sampling both the environment and inner core of tropical cyclones (TCs). This study will focus on the use of GH observations to complement satellite observations to improve and optimize TC analyses and forecasts.

While the GH has the capability to remain airborne for up to 24 hours and thus sample TCs for much longer durations than traditional manned reconnaissance aircraft, global and regional data assimilation systems in their current operational configurations still only assimilate data in 6-h windows, which, in many situations, may not provide sufficient coverage of the TC inner core and its surrounding environment. Therefore, the presence of any satellite instruments sampling the TC and the coverage of these satellite observations could still have substantial impact on TC forecasts, even when TCs are sampled by the GH. Our preliminary results indicate that aircraft observations have the potential to complement satellite observations in significant ways; for example, combining high-resolution thermodynamic observations from the GH with satellite infrared-based retrievals in the TC environment provide more accurate analyses and forecasts. We will present further examples of such use of observations from several instruments on the GH in combination with satellite observations. We will also present preliminary results related to using observations from the High Altitude MMIC Sounding Radiometer (HAMSR) cros-track microwave sounder, which will be operating on the GH during the 2016 hurricane season.