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Data Set ID:

GLAS/ICESat L2 Global Planetary Boundary Layer and Elevated Aerosol Layer Heights, Version 33

The Geoscience Laser Altimeter System (GLAS) instrument on the Ice, Cloud, and Land Elevation Satellite (ICESat) provides global measurements of polar ice sheet elevation to discern changes in ice volume (mass balance) over time. Secondary objectives of GLAS are to measure sea ice roughness and thickness, cloud and atmospheric properties, land topography, vegetation canopy heights, ocean surface topography, and surface reflectivity.

GLAS has a 1064 nm laser channel for surface altimetry and dense cloud heights, and a 532 nm lidar channel for the vertical distribution of clouds and aerosols.

Level-2 planetary boundary layer (PBL) and elevated aerosol layer heights data (GLA08) contains PBL heights, ground detection heights, and top and bottom heights of elevated aerosols from -1.5 km to 20.5 km (4 sec sampling rate) and from 20.5 km to 41 km (20 sec sampling rate).

Each data granule has an associated browse product that users can quickly view to determine the general quality of the data in the granule. Browse products consist of image plots of key parameters and statistics. Data are in scaled integer binary format, big-endian (Unix) byte order, and are available via FTP.

Version Summary:

For information about Version 33, see the NSIDC ICESat Description of Data Releases page.

Geographic Coverage

  • Aerosols > Aerosol Particle Properties
  • Altitude > Planetary Boundary Layer Height
Spatial Coverage:
  • N: 86, S: -86, E: 180, W: -180

Spatial Resolution:
  • 60 m to 70 m x 60 m to 70 m
Temporal Coverage:
  • 20 February 2003 to 11 October 2009
Temporal Resolution: 1288 minute
Data Format(s):
  • Binary
Platform(s) ICESAT
Version: V33
Data Contributor(s): H. Zwally, Robert Schutz, Steve Palm, William Hart, Dennis Hlavka, James Spinhirne, Ellsworth Welton
Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Zwally, H. J., R. Schutz, W. Hart, D. Hlavka, and S. Palm. 2011. GLAS/ICESat L2 Global Planetary Boundary Layer and Elevated Aerosol Layer Heights, Version 33. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: http://dx.doi.org/10.5067/ICESAT/GLAS/DATA221. [Date Accessed].
No technical references available for this data set.


Since two different algorithms are used in GLA08 (GLAH08) and GLA09 (GLAH09), are the aerosol layers different between the two products?

GLA09 (GLAH09) should not contain elevated aerosol layers, only cloud heights. If the GLA09 (GLAH09) algorithm detects a layer in the data, a cloud/aerosol discrimination routine is called. If the layer is considered cloud, then it is output to GLA09 (GLAH09). If it is... read more

GLA08 and GLA09 were originally designed to use only the 532 nm profiles from GLA07; however, these two products use the 1064 nm channel data in addition to 532 nm. Where do the 1064 nm layers come from, and do the 532 nm and 1064 nm algorithms differ?

The GLAS science team added the 1064 nm-based layer detection just a few months before ICESat launched, because they discovered potentially serious problems in the 532 nm channel. The initial design of the software only used the 532 nm channel because of its superior data quality; however, when... read more