The maximum number of thunderstorms in the United States occur in Central Florida. The cloud-ground lightning from these storms is responsible for extensive damage to life and property. The lightning from these storms is also responsible for delays and cancellations of space shuttle launch attempts at the Kennedy Space Center (KSC) and the 45th Space Wing unmanned launches at Cape Canaveral launch facilities. For these and other reasons accurate forecasting of cloud-ground lightning is of crucial importance. The second phase of NASA's Tropical Rainfall Measuring Mission Texas and Florida Underflights project (TEFLUN-B) was conducted between 1st August and 30th September, 1998. The S-band dual-polarization radar (S-Pol) belonging to the National Center for Atmospheric Research (NCAR) was part of the surface based facilities during this project, and was located at Melbourne, Florida. This provided an excellent opportunity to observe Florida thunderstorms with the help of a dual-polarization radar. This project aims at developing cloud-ground lightning forecasting signatures by analyzing S-Pol data for 10 thunderstorms that occurred over the Kennedy Space Center. Time-height trends of reflectivity, ice and graupel-hail as well as electric potential trends for these storms are taken into consideration while developing the forecasting signatures. This thesis proposes that a 35dBZ echo at the -5[degree]C temperature level is the best indicator of imminent CG lightning with a POD of 90%, an FAR of 10% and a CSI of 81.8%. An electric potential level of approximately 1000 V/m also indicates the onset of cloud-ground lightning. An analysis of the microphysical structure of the thunderstorms reveals that the presence of graupel-hail at the -10[degree]C temperature level is necessary in order for cloud-ground lightning to occur.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-1147 |
| Date | 01 January 2004 |
| Creators | Ramakrishnan, Kartik |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
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