| M.D. King Earth Sciences Directorate Goddard Space Flight Center Greenbelt, Maryland 20771 301-286-7208 Internet: king@climate.gsfc.nasa.gov |
S.C. Tsay Laboratory for Atmospheres Goddard Space Flight Center Greenbelt, Maryland 20771 301-286-9710 Internet: tsay@climate.gsfc.nasa.gov |
The MODIS Airborne Simulator (MAS) is a recently developed spectrometer designed to meet the scientific requirements for airborne remote sensing of clouds, aerosols, water vapor and land. The MAS onboard the NASA ER-2 aircraft was designed for simulating measurements to be obtained in the late 1990s from the Moderate Resolution Imaging Spectroradiometer (MODIS), a satellite spectroradiometer being developed for the Earth Observing System (EOS). During the ASTEX campaign, conducted from Terceira, Azores in June 1992, the MAS obtained many multispectral images of marine stratocumulus clouds in the eastern Atlantic.
An interesting case for cloud microphysics and radiation interaction occurred
on June 17. Imagery obtained on this day was selected and analyzed to derive
the effective radius and optical thickness of these clouds by using two of the
MAS visible and near-infrared channels (0.665 and 2.142 um). Color images of
these results will be presented to demonstrate the spatial distribution of
these clouds, which apparently formed in different air mass regimes. The
marginal and joint probability density functions of optical thickness and
effective radius will be presented and discussed to better understand
quantitatively the statistics of these clouds. Future developments of MAS as
well as our cloud retrieval scheme will also be outlined.