Tropical Cyclone Reconnaissance with the Global Hawk: Operational Thresholds and Characteristics of Convective Systems Over the Tropical Western North Pacific.

摘要

In a tropical cyclone (TC), in situ observations measure storm location, intensity, and structure. These parameters are valuable for initializing numerical models and providing forecasters with current conditions on which to base their forecast. Over the western North Pacific (WPAC), a lack of in situ observations in TCs is hypothesized to be one component that contributes to a recent leveling of forecast skill. In this study, the use of a Global Hawk (GH) unmanned aerial vehicle as an observing platform for TCs over the WPAC is examined. It is hypothesized that the GH can greatly benefit the Department of Defense by reducing the uncertainty in TC track forecasts, which has been mandated by the U.S. Pacific Command as a priority for increasing the area of sea maneuverability A limit to successful GH operations is the ability to operate at altitudes above typical cloud tops of WPAC TCs. A climatology of WPAC TC cloud-top heights and temperatures was examined to relate these parameters to storm characteristics. It is concluded that use of a GH for tropical cyclone reconnaissance in the WPAC is a viable option to provide in situ observations of tropical cyclone characteristics for improved model and operational forecasts.