The Relationship of Lightning Activity with Microwave Brightness Temperatures and Spaceborne Radar Reflectivity Profiles in the Central and Eastern Mediterranean

Abstract

In this paper, the relationship of lightning activity in the central and eastern Mediterranean with the 85-GHz polarization-corrected temperature (PCT) and radar reflectivity provided by the Tropical Rainfall Measuring Mission (TRMM) satellite is investigated. Lightning observations were mainly provided by the Met Office?s Arrival Time Difference system as well as by the TRMM Lightning Imaging Sensor. The studied period spans from September 2003 to April 2004 and focuses on the events with the most important lightning activity. It was found that 50% of the cases with flashes have PCTs lower than 225 K, while only 3% of the ?no lightning? cases have PCTs below this value. Further, if PCT is used as a proxy for the presence of lightning, the value of 217 K gives the best statistical scores for the presence of at least one observed flash. In addition, the ratio of cloud-to-ground lightning to total lightning activity has higher values for the ?colder? PCT values and decreases as PCT increases. In addition, the mean and maximum reflectivity profiles with collocated lightning are from 3 to 10 dB and from 6 to 15 dB, respectively, higher than that without lightning. Further, a reflectivity profile with values greater than 53 dBZ in the low levels (below 3 km), of ?45 dBZ at 5 km and 40 dBZ at 7 km is associated with a probability of 80% for lightning occurrence.