DOI: 10.5281/zenodo.4489055
title: Global Water Body Levels Derived from ICESat-2

description: This dataset contains water level records derived from ICESat-2 for 227,386 lakes spanning Oct 14, 2018 to July 16, 2020. These records have been updated to reflect an error in the calculation of lake area in the previous version which led to an overestimation of lake area at high latitudes. For details on how this correction was performed, please see the 2023 Addenda to Cooley et al (2021). A complete description of the method used to derive water level from ICESat-2 can be found in Cooley et al (2021), but is briefly summarized below: We create a conservative water mask modified from the Global Surface Water Occurrence (GSWO) product (Pekel et al., 2016); We intersect ATL08 mean terrain height returns with this water mask, requiring water bodies to receive at least three ICESat-2 point observations on the same day to be included in the analysis; We filter observations based on the mean standard deviation of returns, among other factors; We aggregate observations to monthly timesteps; We calculate seasonal variability in water level as the maximum minus the minimum monthly water level over the 22-month period. This dataset contains: <strong>ICESat2_lake_variability_v2_updated.shp</strong>: A shapefile containing lake points and summary statistics (i.e. height variability, storage variability, etc) <em>*updated to include corrected lake area and storage values</em> <strong>ICESat2_lake_height_time_series_v2_updated.csv</strong>: A csv file of the monthly water height time series used to calculate the global lake level variability <em>*updated to include corrected lake area values</em> <strong>265 water mask GeoTiffs</strong>: Water masks created from GSWO which we intersect with ICESat-2 data to produce the water level time series <em>*unchanged from previous version</em> <strong>ICESat2_mask_reference_v2_updated.csv</strong> – A csv file which lists the corresponding water mask for each water body in the dataset <em>*updated to include corrected lake area values</em> <strong>USGS_height_validation_v2_updated.csv </strong>– A csv file containing the height comparison between ICESat-2 and USGS gauges used for validation and uncertainty analyses <em>*updated to include corrected lake area values</em> <strong>USGS_range_validation_ v2_updated</strong>.<strong>csv </strong>– A csv file containing the range comparison between ICESat-2 and USGS gauges used for validation and uncertainty analyses <em>*updated to include corrected lake area values</em> <strong>California_storage_validation_v2_updated.csv </strong>– A csv file containing the storage comparison between ICESat-2 and California Department of Water Resource gauges used for validation and uncertainty analyses <em>*updated to include corrected lake area and storage values</em> See the README file for a more detailed description of this dataset. Anyone wishing to use this dataset should cite Cooley et al. 2021) and contact Sarah Cooley at scooley2@uoregon.edu with a description of the work and any questions so that we may offer guidance in regards to the best usage of our dataset. Cooley, S.W., Ryan, J.C., and Smith, L.C., (2021), Human alteration of global surface water storage variability, <em>Nature, </em>https://doi.org/10.1038/s41586-021-03262-3