Evaluating the Impact of Hurricane Observations from the Unmanned Coyote Aircraft in Observing System Simulation Experiments

During recent reconnaissance missions into Hurricane Edouard (2014), NOAA conducted the first-ever air-deployed UAS experiments into a tropical cyclone environment. On September 16^th 2014, Sensintel’s 13-lb, 5-ft-wingspan Coyote UAS was released into Major Hurricane Edouard’s eye. NOAA’s P-3 crewed aircraft launched the UAS and provided in-flight command, control and data delivery support for the Coyote. At an approximate altitude of 2900 ft, the UAS penetrated Edouard’s western eyewall and recorded platform record-breaking winds of 100 kt as it proceeded to ‘orbit’ this high-wind region during its historic 28-minute inaugural mission. Positive impacts from assimilating these observations in a vortex-scale data assimilation system have been presented in previous meetings. Yet, Coyote datasets from actual hurricane missions remain very limited in sample size and naturally reflect current technological capabilities.

Observing System Simulation Experiments (OSSEs) offer the most suitable methodology to investigate optimization of sampling strategies with a current observing platform and potential impacts of its future technological advancements. In this presentation, we will discuss the results of such an investigation with the Coyote UAS platform, for which observations will be simulated from the Nolan et al. (2013) nature run (NRH1) and assimilated using NOAA’s HWRF and HEDAS modeling and data assimilation systems. Specifically, our investigation focuses on how to optimize Coyote UAS sampling strategies for model initialization in the presence of other aircraft and satellites observing the same tropical cyclone. Considerations for future expansion alternatives will also be presented including, but not limited to, longer battery life that allows for longer flight times, advances in current sensors that allow for more frequent in-situ sampling of the vortex, and/or addition of new sensors that allow for measurement of additional characteristics of the vortex.