Development of the ensemble Kalman filter system for hurricane data assimilation at NOAA/AOML/HRD: Preliminary evaluation using environmental and vortex-scale dropwindsonde data

The Hurricane Research Division (HRD) at NOAA's Atlantic Oceanographic and Meteorological Laboratory (AOML) routinely conducts flight missions into hurricanes to collect synoptic-scale surveillance (by the G-IV aircraft) and high-resolution inner-core (by the P-3 aircraft) data, including flight-level, dropsonde, surface wind speed, and Doppler radar observations. Currently, while the synoptic-scale surveillance data are assimilated by most operational centers, due to lack of sufficient resolution and sophisticated data assimilation tools, the utilization of the high-resolution data for the initialization of hurricane forecast models is limited at best.

The HRD has recently committed to the development of a state-of-the-art ensemble Kalman filter (EnKF) data assimilation system to utilize the high-resolution inner-core data obtained from flight missions, as part of NOAA's Hurricane Intensity Improvement Program (HFIP). Within this development effort, assimilation of dropwindsonde observations is considered as one of the higher-priority tasks, as dropwindsondes provide very valuable information on overall tropical cyclone structure throughout the depth of the troposphere. In this talk, a brief report on the overall progress of the EnKF system and recent results using environmental and vortex-scale dropwindsonde data will be presented.