Kahn, Leonard [faculty advisor, Department of Physics]




Extratropical Cyclones; QuikSCAT; Hurricane Force


Since June 1999, NASA’s Quick Scatterometer Spacecraft (QuikSCAT) has been providing forecasters at the Ocean Prediction Center (OPC) with Near-Real-Time (N.R.T.) surface wind speed and direction data over the world’s oceans. QuikSCAT has allowed forecasters to better predict potential hazards such as storm surges and issue warnings when necessary. Over the past decade, QuikSCAT has received a number of upgrades which improved the forecasters’ abilities to predict the weather more accurately and issue warnings, accordingly. Improvements included the availability of the QuikSCAT data within the forecasters’ workstations starting in October 2001, the introduction of higher resolution satellite data in May 2004, and an improved wind algorithm/rain flag in October 2006. These improvements resulted in an increasing trend in the number of hurricane force extratropical cyclones in each cyclone season, which is not necessarily accurate. Now with four accessible sets of QuikSCAT data (N.R.T. and Science-level 12.5-kilometer and 25-km), the OPC must determine which data set best accurately represents current wind conditions. The goal of the research provided herein is to provide both a quantitative and qualitative analysis of hurricane force extratropical cyclones in the Pacific Ocean. First, using the 12.5-km Science-level data, the number of cyclone events for given storm seasons (September - May) will be determined. Secondly, a comparison of the four QuikSCAT data sets will be made by providing a case-by-case analysis of hurricane force extratropical cyclones. From these two studies, the data of hurricane force extratropical cyclone events for years prior to the implementation of the higher resolution QuikSCAT data and the improved wind algorithm/rain flag can be normalized and forecasters can determine which data set, or combination of data sets, most accurately represents current wind conditions. With the failure of the QuikSCAT satellite in November 2009, the information taken from this research will be valuable for the design and launch of a future satellite.