HR: 10:25h
AN: AE41B-01 INVITED     [PDF]
TI: New Space Shuttle Observations of Transient Luminous Events During the MEIDEX
AU: * Yair, Y
EM: yoavya@openu.ac.il
AF: The Open University of Israel, 16 Klausner St., Tel-Aviv, 61392 Israel
AU: Price, C
EM: cprice@flash.tau.ac.il
AF: Tel-Aviv University, Haim Levanon Rd., Tel-Aviv, 69978 Israel
AU: Israelevitch, P
EM: peter@luna.tau.ac.il
AF: Tel-Aviv University, Haim Levanon Rd., Tel-Aviv, 69978 Israel
AU: Devir, A
EM: iardad@iard.org.il
AF: Tel-Aviv University, Haim Levanon Rd., Tel-Aviv, 69978 Israel
AU: Moalem, M
EM: meir_moalem@yahoo.com
AF: IAF, Space Branch, Tel-Aviv, 61909 Israel
AU: Ziv, B
EM: baruchz@openu.ac.il
AF: The Open University of Israel, 16 Klausner St., Tel-Aviv, 61392 Israel
AU: Levin, Z
EM: zev@hail.tau.ac.il
AF: Tel-Aviv University, Haim Levanon Rd., Tel-Aviv, 69978 Israel
AU: Joseph, J
EM: yoya@luna.tau.ac.il
AF: Tel-Aviv University, Haim Levanon Rd., Tel-Aviv, 69978 Israel
AB: The Mediterranean Israeli Dust Experiment (MEIDEX) was conducted on-board the space shuttle Columbia during its last mission in January 2003. Nocturnal observations with a multispectral CCD video camera were targeted above thunderstorms near the Earth's limb, with the aim or recording Transient Luminous Events (TLEs) in the mesosphere. Most of our nighttime observations were conducted in the SE-Pacific (Australia and Papua-New Guinea), equatorial Africa, the southern Indian Ocean and South America. Relevant inputs and information on the active storms during a specific orbit were uplinked to the crew daily. The necessary shuttle attitude maneuvers were deduced based on the use of (almost) real-time IR satellite images and VLF lightning location data that were available on the Internet. In order to enhance the probability of success of each observation, the astronauts were instructed to visually observe lightning activity (easily discernable from the shuttle) and to direct the gimbaled camera toward these regions. A total of more than 8 hours of video obtained during the MEIDEX was saved, and it includes a considerable amount of new sprite data. Most events were captured at ranges 1600-1900 km from the shuttle, using the red filter (665nm). The results suggest the occurrence rate of sprites and elves over oceanic and continental storms may be higher than earlier estimates. Strong enhancements of the brightness of the airglow layer above lightning flashes were observed, with lateral dimensions on the order of 400-500 km. It is assumed that these may be Elves observed edge-on, though it may also be a new type of airglow enhancement. The calculated brightness of these events is in the range 2.2-8.8 MR. This phenomena seems to be widespread and is probably a manifestation of the interaction between lightning EMP and QE fields and the lower nocturnal ionosphere. A unique observation from space of the Congo basin in Africa caught a chain of events where in the span of less than 2 minutes two meteors penetrated above a thunderstorm, that immediately afterwards generated several Sprites and Elves in the same atmospheric volume. This seems to confirm earlier observations and theoretical work on the role of meteors in mesospheric TLE generation. International, multiple-station ground-based ELF-VLF data obtained during the mission is used for geo-location of the parent flashes of the optically visible TELs.
DE: 0310 Airglow and aurora
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting