Tuesday, 24 January 2012
Severe Storm Identification with the Advanced Microwave Sounding Unit (AMSU)
Hall E (New Orleans Convention Center )
Previous work by Cecil (2009, 2011) and Cecil and Blankenship (2011, in press) have demonstrated a strong relationship between the occurrence of hail and the microwave brightness temperatures primarily at 37 GHz. These studies were performed with the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and the Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sensors. NOAA and EUMETSAT have been operating the Advanced Microwave Sounding Unit (AMSU-A and -B) and the Microwave Humidity Sounder (MHS) on several operational satellites since 1998: NOAA-15 through NOAA-19 and MetOP-A. With multiple satellites in operation since 2000, the AMSUIMHS sensors provide near global coverage every 4 hours, thus, offering a much greater sampling of the diurnal cycle than TRMM or AMSR-E. With similar observation frequencies near 30 GHz and additionally three at the 183 GHz water vapor band, the potential to detect strong convection associated with severe storms on a more comprehensive time and space scale exists. Preliminary studies have indicated a strong signature at these channels associated with large hail episodes over the United States (e.g., the Vivian, SD July 2010 record sized hail stone produced some of the coldest AMSU/MHS temperatures ever witnessed). In this study, we develop an AMSU-based climatology of hail occurrence over the continental U.S and compare it with the results found by Cecil et al. The climatology is developed based on AMSU brightness temperatures correlated with severe storm reports generated by the Storm Prediction Center. Case study examples will also be presented. The performance of the hail detection will also be discussed in context with the potential development of a geostationary based microwave sensor.