TAU Trends in Research June 1999

Israeli Astronaut to Study Desert Storms from Space

The first Israeli astronaut, Ilan Ramon (backup Itzhak Mayo) is tentatively scheduled to fly on board the U.S. Space Shuttle Colombia in October 2000 or in the Spring of 2001. He will conduct an experiment designed by TAU atmospheric scientists Profs. Zev Levin, Joachim Joseph and Yuri Mekler and their colleagues. The experiment, which was approved for the mission by both the Israel Space Agency and NASA, will simultaneously measure aspects of dust storms over the Mediterranean Sea from space and from a research airplane flying through the storms below. A network of ground-based stations throughout the Mediterranean area and synoptic forecasts of dust plume occurrence will provide additional supporting information.

Spectroscopic analysis of desert aerosols

The project seeks to optimize and intercalibrate the primary current methods for the remote detection and investigation of desert aerosols. This will allow integrating all available sources of information on aerosols into one common database. The idea is to simulate the two current major NASA satellite systems capable of sensing aerosols, TOMS and MODIS, in one shuttle-borne instrument to observe a single atmospheric volume containing desert aerosols. The simultaneous airplane and ground-based measurements, should provide an absolute calibration for future observations of dust storms and thus contribute decisively to future investigations of the geographical variation of the optical, physical and chemical properties of desert aerosols, including the location and temporal variation of their sources, sinks and transport.

This Mediterranean Israeli Dust Experiment (MEIDEX) includes measurements of light scattering by desert aerosol particles in six different wavelength intervals, from the near ultraviolet (UV) to the solar infrared (IR). The wavelengths include two used by TOMS as well as four of those installed on MODIS. The payload consists of one gimbal-mounted CCD radiometric camera, functioning in the UV, visible and IR. The camera will observe a volume of atmosphere containing desert aerosol over both land and sea, illuminated by solar radiation.

The supporting ground-based and airborne measurements include optical observations, directly sampled aerosol-size spectra, and the chemical analysis of dust samples. Since all observations will be over the Mediterranean Sea, the research airplane will fly out from the island of Crete. Good regional and local weather forecasts of approaching dust events are important for increasing the observations of dust plume events. For this purpose, the researchers are developing numerical simulations of dust transport in the atmosphere to help forecast dust plume occurrences and to better determine their evolution and trajectories. Such models and experiments should also improve our understanding of atmosphere-aerosol interactions.

For further information please contact:

Prof. Zev Levin
Department of Geophysics and Planetary Sciences
Tel Aviv University
Ramat Aviv, Tel Aviv 69978
ISRAEL

Tel/Fax:	972-3-640-8274
E-Mail:	zev@hail.tau.ac.il