On the Application of Microwave Satellite Data to Assess Changes in Storminess over the Pacific Ocean

This study analyzes 25 years of Special Sensor Microwave Imager (SSM/I) retrievals of rain rate and wind speed to assess changes in storminess over the open water of the Pacific Ocean. Storminess is characterized by combining trends in both the statistically-derived 95th percentile exceedance frequencies of rain rate and wind speed (i.e., extremes), and is computed annually and seasonally, with further partitioning done by phase of the El Niño Southern Oscillation (ENSO) index and the Pacific Decadal Oscillation (PDO) index. The resulting storminess map resembles a traffic light, with red, yellow, and green shading, providing a quick look at those areas which are essentially most “at risk” due to the recent trends in extremes of heavy rains and strong winds. The presentation will highlight three main foci: 1) the storminess maps, showing the most prone regions of the Pacific to extreme rain and wind; 2) how the trends in rain and wind shift within varying teleconnection states; and 3) challenges with putting this information into the island context for use by decision-makers.