HR: 15:15h
AN: A53A-06 [Abstracts]
TI: Applications of GLAS Satellite Lidar Cloud, Aerosol and PBL Measurements at High Spatial Resolution
AU: * Spinhirne, J D
EM: james.spinhirne@nasa.gov
AF: NASA, GSFC 613.1, Greenbelt, MD 20771, United States
AU: Palm, S P
EM: spp@virl.gsfc.nasa.gov
AF: SSAI, GSFC 613.1, Greenbelt, MD 20771, United States
AB:
The Geoscience Laser Altimeter System, GLAS, beginning in 2003, provides space borne lidar observations of
global clouds and aerosol from polar orbit. The measurements in fall 2003 and spring 2004 include highly
sensitive aerosol detection and profiling by photon counting detection at 532 nm wavelength to backscatter cross
section below 10-7 1/m-sr. Data products from the measurements include aerosol optical depth of layers and
the profile of extinction cross section. An analog channel at 1064 nm also gives aerosol profiles, and
measurements include the precise pulse reflectance from the surface. A special data product is the height of the
planetary boundary layer, PBL, from analysis of the signal structure. Over the ocean, we have shown that the
pulse reflectance is a function of wind speed. The satellite lidar data is uniquely accurate for the global height
distributions of scattering layers. However due to the height and speed of the platform, the measurement cannot
be applied to as high a resolution as aircraft or ground based measurements. For GLAS data products, limiting
horizontal resolution can be as low as 176m for cloud heights and as large as 28 km for aerosol optical
thickness. Surface signals over the ocean will allow higher resolution analysis of some parameters. An
application of the GLAS data has been comparison to model cloud or aerosol distribution with the goal of
improving cloud and aerosol parameterizations in GCM's and aerosol transport models. Initial comparisons are
completed. A full description of the GLAS data products and their resolution factors will be presented. Examples
of how the data may be applied to model comparisons, such as ECMWF clouds, PBL height aerosol transport,
and polar blowing snow will be described.
UR: http:glo.gsfc.nasa.gov
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0321 Cloud/radiation interaction
DE: 0394 Instruments and techniques
DE: 3311 Clouds and aerosols
DE: 3329 Mesoscale meteorology
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly