March 27, 2007 Using H*Wind to Improve Satellite-Based Wind Measurements in Tropical Cyclones John Allard Faculty Advisor: Dr. Christopher C. Hennon Introduction The experimental Real Time Hurricane Wind Analysis System (H*Wind) was developed by the Hurricane Research Division of the National Oceanic and Atmospheric Administration H*Wind is state of the art in processing tropical cyclone wind observation platforms into a common standard framework. H*Wind is being used to support research and a wide variety of applications including wave and storm surge modeling disaster assessment, and analyses of available data An H*Wind analysis is primarily used to produce accurate data which aids in documenting and responding to a hurricane disaster. Examples of observation platforms found in the H*Wind database include but are not limited to satellites, aircraft reconnaissance, ship observations, GPS dropsondes, and buoys. Their measurements produce valuable data in determining correct wind estimates. Our research focuses on data produced by NASA’s QuikSCAT satellite. QuikSCAT is a polar orbiting satellite that measures open ocean wind vectors and is particularly useful with tropical cyclone winds. Applications QuikSCAT’s wind retrieval capabilities are limited. Erroneous measurements arising from these limitations are due to the contamination of very heavy rain associated with tropical cyclones. H*Wind is currently being used to improve wind retrieval capabilities of QuikSCAT and other observation platforms. The above image shows Quikscat’s global morning passes from 3/22/2007. Method A time of interest is determined by the researcher, such as the time of a QuikSCAT pass for a particular tropical cyclone. A time interval is chosen in H*Wind’s database to encompass the time of interest (usually three hours prior to and after). H*Wind will display an array of wind observations from every available platform as vectors showing wind magnitude and direction. The researcher determines which data is relevant toward their particular application. Example: Data from flight level is eliminated if surface winds are needed. Quality control (QC) is performed by the researcher to eliminate poor data H*Wind will now perform an objective analysis on the chosen data and results are found in the analysis output. Conclusion Together, QC and objective analyses improve the forecaster’s or researcher’s ability to accurately determine open ocean wind speeds found in tropical cyclones. The use of H*Wind will aid in the development of new algorithms for the improvement of wind retrievals from NASA’s QuikSCAT satellite. H*Wind supports a UNCA grant from NASA to improve open-ocean wind vector retrievals. Example of an analysis output, Hurricane Katrina prior to landfall, 28 Aug 2005 Maximum surface wind speeds: 141 kts Figure A A good example of observations displayed as wind vectors. Notice the types of platforms chosen after QC. Flagged Data represents eliminated poor data points. Figure B Notice how the H*Wind analysis smoothes data into a comprehenive wind field. Senior Symposium Hurricane Rita Hurricane Katrina