MEIDEX –MEDITERRANEAN ISRAELI DUST EXPERIMENT FOR

THE FIRST ISRAELI ASTRONAUT FLIGHT

• An experiment on board the shuttle within the Hitchhiker program• Under an agreement between NASA and ISA (Israeli Space Agency)

WHY STUDY DUST STORMS?• Desert dust particles are a major component of natural aerosols in the atmosphere

• They may help to cool or warm the atmosphere depending on their size and chemical composition

• They affect clouds and precipitation

• They are in the right particle size to affect our health being deposited in the lungs

•They affect mechanical systems (e.g. jet engines, helicopters etc.)

• They reduce the contrast in remote sensing measurements

• They affect biological activity in the Ocean

Desert dust particles Dust storm over the Dead Sea

Dust in Sahara – view from space Desert dust in Tel Aviv

Non-Absorbing Aerosols in the Atmosphere

Major sources and transport routes of the desert dust

The Effects of Dust Particles on Climate

• They affect climate by changing the dolar albedo – direct effect• They affect climate by modifying cloud characteristics – indirect effect• They affect rainfall amounts and intensities (dust + sulfate + organic matter)

Other Existing Experiments for Measuring Dust Aerosols

MODIS – instrument aboard TERRA satellite – was launched in January 2000

TOMS - aboard Earth Probe satellite – uses UV wavelengths – mostly sensitive to dust at higher altitudes

MEIDEX Science TeamPrincipal Investigators:• Prof. Zev Levin• Prof. Joachim JosephAstronauts:• Col. Ilan Ramon• Lt-Col. Itzhak MayoTeam members:• Dr. Adam Devir• Dr. Eliezer Ganor• Prof. Peter Israelevich• Mr. Edmund Klodzh• Prof. Yuri Mekler• Mr. Meir Moalem• Dr. Yoram Noter• Mr. David Shtivelman• Mr. Amit Teller• Dr. Yoav Yair – Project Manager

The team consists of scientists from different disciplines:• Remote sensing of the atmosphere• Radiative transfer • Aerosol measurements and analysis• Modeling of atmospheric processes• Instrumentation for remote sensing and for airborne aerosol sampling

SCIENTIFIC OBJECTIVES

DAYTIME PRIMARY EXPERIMENTS:• Validate TOMS versus MODIS• Sources, Transport, Sinks and Properties of Desert Aerosol over the Mediterranean and Atlantic Ocean• Absolute calibration by ground and airborne measurements

DAYTIME SECONDARY EXPERIMENTS:• Spectral Sea Surface BRDF with emphasis on UV • Construct Visual Slant Visibility Model

NIGHT TIME EXPERIMENT (TERTIARY):• Sprites, Elves and other related phenomena

The Regions of Interest

Preferred Seasons:

• The best season is Spring (March to May) – we are scheduled to fly in spring 2001

• The secondary choice is the Fall (September to November)

STS-107• “Space Lab”- 33 Experiments • Fast Reaction Experiment Enabling Science,

Technology Applications & Research - FREESTAR• Primary Experiment: MEIDEX • Launch: April 4, 2002

MEIDEX on FREESTAR@STS107

Xybion IMC- 201 radiometric CCD camera

• CCD Sensor: 756Hx581V

• Sensitivity ≥10-6fc (~ 0.1 of typical night sky)

• Spectral range: 340-860nm

• 6 bands: 0.34, 0.38, 0.44, 0.56, 0.66, 0.86 nm

• Exposure Times: 50 nsec - 4 msec in 50 nsec steps

WFOV SEKAI White Light video camera

MEIDEX Optical Bench Mount• Cameras are mounted in a 1-axis gimbaled truss

• Gimbal angular range: ± 22.5 Degrees

• Scan direction: ± Y

• FOV Xybion: 16o (68km at the altitude 256km - about 100m/pixel nominal resolution)

• FOV SEKAI: 60o (270 km at the altitude 256 km)

Xybion camera

Upper End Plate w/ Quartz Window

Gimbal Motor & Worm Drive

Worm Gear

SEKAI WFOV Camera

Lower End Plate

Lens & Baffle

Xybion Camera

Avionics Mount Plate w/ electronics

OVERALL MEIDEX CONFIGURATION

1. Wing mounted optical spectrometers (0.1 to 3 m, and 0.3 to 47 m)

2. Isokinetic sampling of aerosol particles on filtered and on EM grids

3. Ram collection of large (>2.5 m) aerosols

4. Two albedometers5. GPS6. Temperature sensors

Airborne Measurements

Flight base: Crete, or Sardinia, or TenerifeRadius: 500 miles

FORECAST

Dust Forecast with the TAU_ETA model and TOMS observations for April 23, 2001

SLANT VISIBILITY“VISIBILITY”: Ability of Human Eye to see a reflecting object through a scattering, absorbing and turbulent atmosphere.Depends on Complex Interaction of Multiple Component System:• Contrast Threshold of Human Eye, • Inherent Spectral Contrast of the Object versus its Background,• Atmospheric Spectral Extinction (x,y,h),• Atmospheric Turbulence (x,y,h),• Geometric Slant Path.IMPOSSIBLE TO CONSTRUCT RELIABLE MODEL BY INFORMATION TRANSFER FROM NON - HUMAN SYSTEMS.Our Experiment:Observation of designated targets along the shuttle footprintas a function of time on a “Yes/No” Basis.Correlation between KNOWN Optical Properties of the Atmosphere and the SUBJECTIVE Detection Capability of the Astronaut’s Eye.

Observations of Sprites• Sprite observation by XYBION camera will be carried our over South America and the Tropics (crucial role of the Astronaut)

• Simultaneous ground observa-tions will be carried out by teams from MIT and from Brazil

• Measurements of VLF waves (in particular Schumann resonances) from TAU Mitzpe Ramon station will be correlated with the space and ground observations

The MEIDEX Data Acquisition Scheme

OPS ORG & DATA FLOW

Surface Obs.AERONET,(GSFC)Huelga, SpainIlurin, Nigeria

Forecast DataNEPC (NOAA)Airport Authority(BG Airport)IAF/MET

FORECASTCENTER

(TAU)

Airport Crew

Plane in Flight

Dust Sat ObsTOMSSEAWIFSMODIS(GSFC)

JSC(Houston)

Shuttle POCC(GSFC)

• Dr. Y. Kaufman and Staff, GSFC - DA’s, Analysis• Dr. B. Holben and Staff, GSFC - AERONET• Dr. E. Hilsenrath and Staff, GSFC -

– Instrument Optical Properties, Calibrations.• Dr. D. Tanre, U. Lille, France - DA’s, CIMEL’s, 6s• Dr. Eric Vermote, UMD, US - Changes in 6s• Dr. R. Pinker, UMD, US - Calibrations in Nigeria• Dr. Victoria Cachorro, U.Valladolid - Calibration Site• Prof. P. Alpert, Dr. S. Krichak, Dr. M. Tsidulko, H. Shafir,

TAU, Dr. B. Ziv, OU - Dust Forecast • Dr. Colin Price, TAU, Prof. Earle Williams, MIT & Many

Others - Sprites & Related Measurements.

Scientific Cooperation