• NSIDC DAAC is currently upgrading our data ingest process for NASA Earthdata Cloud. During this transition, users may notice temporary interruptions in data availability or notice small data gaps. All gaps will be resolved as quickly as possible. During this upgrade jpeg browse imagery will also not be available for preview in Earthdata search. Please reach out to NSIDC User Services with any questions or concerns.

  • ICESat-2 data sets ATL03 V5, ATL06 V5, ATL07 V5, ATL08 V5, ATL10 V5, ATL12 V5, and ATL13 V5 contain a geolocation error that results in a mean across-track position error of 1.5 m (up to 8 m) beginning 24 October 2021. On average, the resulting height errors are small (< 1 cm), and the mean along-track position error is 0.5 m (up to 4 m).

  • The NSIDC DAAC is retiring access to its legacy, on-premises data archive and transitioning to the NASA Earthdata Cloud as the primary data archive. View planned retirement dates here.

ATLAS/ICESat-2 L3A Sea Ice Freeboard, Version 5
Data set id:
ATL10
DOI: 10.5067/ATLAS/ATL10.005
There is a more recent version of these data.
Version Summary
Changes for this version include:

  • The ATL10 QA check for insufficient output failure was updated. The code now checks for the number of valid freeboard ice segments and number of valid, un-interpolated, reference surfaces. Previously, the total number of freeboard ice segments written (valid and invalid) were counted, and the number of reference surfaces was not considered. A new controllable parameter, min_refsurf_count, was added to control the minimum reference surface count threshold (l3a_fb_cont_mod).

  • The description of the reference surface interpolation flag has been updated to match the procedure in the atlas_l3a_fb code A controllable parameter used in the reference surface interpolation flag was also added to replace a hard coded value (max pad time).

  • The height segment inverted barometer variable was moved to the geophysical group from the height segments group (it was already in the geophysical group in ATL07).

  • The computation of the reference surface height has been updated to better match the description in the ATBD (essentially a minor bug fix).

  • The MMS, Geoid, and the two free-to-mean parameters have been calculated at the reference surface-scale (e.g. 10 km, weighted by lead group size) and added to ATL10.

  • The along track distance has been calculated at the beam reference surface and lead group scale.

  • The reference surface time and location has been updated to be set to the center of the reference surface. Previously, the location was found by simply averaging data from all the segments within the 10 km sections which caused some odd behavior (skewed locations towards the sides of the sections). The reference surface lat/lon/time is now determined using interpolation. For reference surfaces set where there are no sea ice segments for a given beam, a filling procedure is used to estimate the reference surface lat/lon. The filling procedure uses a distance routine to find the lat/lon for a point a given distance from a known point, in a known direction.

  • The new PODPPD flag, and updated segment_type flag, are read from ATL07 and used in filtering which sea ice segments are used in freeboard processing. Now, if there is a calibration scan maneuver occurring, the freeboard segment in ATL10 is invalidated. A new pointing angle variable is also calculated (from the co_elev variables) and is used to further filter the freeboard segments (currently default of 1 degree from nadir).

  • An error in the computation of reference surface sigma values let to missing sigma variables for individual freeboard segments. The error was corrected by simply interpolating from nearby reference surface sigma values. Future work will look to update this approach. Note: The missing reference surface sigmas were only present for reference surfaces with an interpolation flag value of 3. Reference surfaces where the height is interpolated also uses an interpolated sigma value. The value of sigma for an interpolated reference surface may be re-visited in the future.

  • Modified the integration test scripts to generate browse products and check for the presence of default 1 and default 2 plots.

  • The ATLAS browse plot for ATL10 reference surface and freeboard heights has been corrected.

  • New parameters of mean ocean sea level pressure dynamic inverted barometer effect from ATL07 and written to ATL10. The new parameters are: /ancillary_data/freeboard_estimation/mean_ocean_slp: Mean ocean sea level pressure computed in ATL07 and /gtx/freeboard_beam_segment/geophysical/height_segment_dynib: Dynamic inverted barometer effect computed in ATL07.These are not currently applied to the heights but could be in future releases.
In this section
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Overview

This data set (ATL10) contains estimates of sea ice freeboard, calculated using three different approaches. Sea ice leads used to establish the reference sea surface and descriptive statistics used in the height estimates are also provided. The data were acquired by the Advanced Topographic Laser Altimeter System (ATLAS) instrument on board the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) observatory.
Parameter(s):
FREEBOARD
Platform(s):
ICESat-2
Sensor(s):
ATLAS
Data Format(s):
HDF5
Temporal Coverage:
  • 14 October 2018 to 12 October 2022
Temporal Resolution:
  • 91 day
Spatial Resolution:
  • Not Specified
Spatial Reference System(s):
  • WGS 84
    EPSG:4326
Spatial Coverage:
  • N:
    90
    S:
    -90
    E:
    180
    W:
    -180
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

Data Access & Tools

This data set has been retired. There is a more recent version of these data.

Documentation

Help Articles

General Questions & FAQs

FAQs About NSIDC DAAC's Earthdata Cloud Migration
This article covers frequently asked questions about the NASA NSIDC DAAC's Earthdata cloud migration project and what it means to data users.
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What subsetting and reformatting services are available for ICESat-2 data?
This short article describes the customization services available for ICESat-2 data using Earthdata Search.
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When will the legacy, on-premises archive be retired?
The NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) is migrating its primary data access from its legacy, on-premises archive to the NASA Earthdata Cloud.
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How to Articles

Filter and order from a data set web page using the Data Access Tool
Many NSIDC DAAC data sets can be accessed using NSIDC DAAC's Data Access Tool. This tool provides the ability to search and filter data with spatial and temporal constraints using a map-based interface.Users have the option to:
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How do I convert an HDF5/HDF-EOS5 file into binary format?
To convert HDF5 files into binary format you will need to use the h5dump utility, which is part of the HDF5 distribution available from the HDF Group. How you install HDF5 depends on your operating system.
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How to use OpenAltimetry for ICESat-2 data products
Learn the basic steps for using OpenAltimetry to browse and download ICESat-2 data products.
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NASA Earthdata Cloud Data Access Guide
The NASA Earthdata Cloud is the NASA cloud-based archive of Earth observations. It is hosted by Amazon Web Services (AWS). Learn how to find and access NSIDC DAAC data directly in the cloud.
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Search, order, and customize NSIDC DAAC data with NASA Earthdata Search
This article highlights the NSIDC DAAC data sets available with customization options and outlines a workflow for searching, ordering, and customizing data in NASA Earthdata Search. This approach is ideal for users who want to download data to their local machine.
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