Mother Nature treated hurricane researchers to a rare light show as they flew the last mission of the most ambitious hurricane study campaign in the Atlantic Ocean. Rarely seen lightning fields and purple sprites were detected in the eye of the hurricane by the ER-2 pilot as he flew more than 19.8 km (65,000 ft) above the Atlantic.
The third Convection and Moisture Experiment (CAMEX-3) officially ends today, although that's not the end of the program. With an extensive collection of data, the scientists and their colleagues will be busy analyzing what they recorded and extracting a better understanding of how hurricanes form and energize as they move across the ocean.
Ironically, the team may have to pack quickly and evacuate, with no time for lengthy farewells (the group photos were already done Saturday) because Georges is threatening Patrick Air Force Base on Florida's east coast, where the CAMEX-3 team is based. The evacuation of the Florida Keys has already been ordered.
The hurricane's farewell gift - the lightning and sprites - are a recently discovered phenomenon that NASA's Global Hydrology and Climate Center, coordinator of CAMEX-3, has been studying. Red sprites and blue jets, as they are known, were seen by high-altitude pilots and Space Shuttle crews in the 1980s, perhaps earlier, but most observers were unsure of what they saw and did not report the events. Sprites and jets are very faint and can be recorded only with cameras using image intensifiers.
Observations from the Shuttle in 1989-91 and aircraft videotapes of sprites in 1993 confirmed their existence. The exact cause remains a mystery, although they appear to be a part of the global electrical circuit.
Tuesday's Georges synoptic/water vapor inflow flight was a success. The hurricane had already made landfall over Hispaniola and was impacting the mountains there. Although Tuesday was the DC-8 Airborne Laboratory's las
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Contact: John Horack
john.horack@msfc.nasa.gov
(256) 544-1872
NASA/Marshall Space Flight Center--Space Sciences Laboratory
23-Sep-1998