• The ATL09 nighttime calibration of the attenuated, calibrated backscatter profiles from approximately 1 Dec 2024 to 20 Nov 2025 is poor due to hard limits on the minimum values used to compute the calibration and on the minimum value of the calibration itself. For more information, refer to the Known Issues document.

ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics, Version 7
Data set id:
ATL09
DOI: 10.5067/ATLAS/ATL09.007
This is the most recent version of these data.
Version Summary
Addition of a new L3A cloud folding algorithm to better detect and flag instances when clouds above 15 km are folded down to the lower few km of the profile; Detection and flagging of layers that are wholly below ground and thus folded; Detection and flagging of folded layers that straddle ground; Setting the layer_attr parameter to a value of 11 when a layer is determined to be folded from above 15 km; Changes to the structure of the layer detection algorithm (DDA) to enable execution of N passes of the DDA; Improved thin layer detection.

Overview

ATL09 contains calibrated, attenuated backscatter profiles (CAB), layer-integrated attenuated backscatter, blowing snow, and other parameters including cloud and aerosol layer height and atmospheric characteristics. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the ICESat-2 observatory.
Parameter(s):
CLOUD PROPERTIES
LIDAR BACKSCATTER
Platform(s):
ICESat-2
Sensor(s):
ATLAS
Data Format(s):
HDF5
Temporal Coverage:
  • 13 October 2018 to present
Temporal Resolution:
  • 91 day
Spatial Resolution:
  • Not Specified
Spatial Reference System(s):
  • WGS 84
    EPSG:4326
Spatial Coverage:
  • Northern latitude
    88
    Southern latitude
    -88
    Eastern longitude
    180
    Western longitude
    -180
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

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