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Description

ATL09QL is the Quick Look (QL) version of ATL09 with an expedited latency of 3‒5 days. QL data are based on the same algorithms that generate the standard products but do not undergo the same rigorous quality checks; thus, they should be used with caution. Once final files are available, the corresponding QL files are removed. ATL09QL 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.

Version Description

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.

Product Summary

Platforms
ICESat-2
Instruments
ATLAS
Projects
LANCE ,
SNWG
Spatial Extent

N: 88 S: -88 E: 180 W: -180

Spatial Resolution
280 Meters
Spatial Reference System(s)
WGS 84 (EPSG:4326)
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
ORBIT
Temporal Extent
2026-01-30 to Present
Temporal Resolution
91 Day
Concept ID
C3566183507-NSIDC_CPRD
Data State
ACTIVE
Number of Files/Granules
1274
Processing Level
3
Published
Science Keywords
Cloud Properties ,
Lidar Backscatter

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Palm, S. P., Y. Yang, U. C. Herzfeld, D. Hancock, K. A. Barbieri, J. Wimert, & ICESat-2 Science Team. (2025). ATLAS/ICESat-2 L3A Calibrated Backscatter Profiles and Atmospheric Layer Characteristics Quick Look, Version 7 [Dataset]. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/ATLAS/ATL09QL.007 Date Accessed: 2026-08-03

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

DATA PRODUCT SPECIFICATION

GENERAL DOCUMENTATION