| Autor: |
Michael D. Desch, William M. Farrell, Richard J. Blakeslee, Richard A. Goldberg, Jeffrey C. Bailey, J. G. Houser, Douglas M. Mach |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Atmospheric Research. 76:386-401 |
| ISSN: |
0169-8095 |
| DOI: |
10.1016/j.atmosres.2004.11.039 |
| Popis: |
The Altus Cumulus Electrification Study (ACES) was conducted during the month of August, 2002 in an area near Key West, Florida. One of the goals of this uninhabited aerial vehicle (UAV) study was to collect time resolved optical pulse data from thunderstorms. During the month long campaign, we acquired 5294 lightning generated optical pulses. Most of these observations were made while close to the top of the storms. We divided our data into two amplitude groups based on prior NASA U2 aircraft optical data and our pulse characteristics. The group of large pulses with radiance greater than 2.1 mW /sq m sr had mean and median 10 - 10% optical pulse widths of 765 and 735 microns respectively, the 50-50% pulse widths of 396 and 355 microns respectively, and 10-90% rise times of 290 and 260 microns. These values are very similar to the previous U2 based optical results The other group of pulses consisting of slightly more than a quarter of the total pulses observed had radiances less than the minimum values detected in the U2 study. The small pulses were narrower than the large pulses with 5040% mean and median values of 198 and 160 ps respectively. Only 12 % of the flashes contained only small pulses, minimizing the impact of this data on the estimates of detection efficiencies of the orbital instruments, the Lightning Imaging Sensor and Optical Transient Detector. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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