摘要：The recent availability of freely and openly availablesatellite remote sensing products has enabled the implementation of globalsurface water monitoring at a level not previously possible. Here we presenta global set of satellite-derived time series of surface water storagevariations for lakes and reservoirs for a period that covers the satellitealtimetry era. Our goals are to promote the use of satellite-derived productsfor the study of large inland water bodies and to set the stage for theexpected availability of products from the Surface Water and OceanTopography (SWOT) mission, which will vastly expand the spatial coverage ofsuch products, expected from 2021 on. Our general strategy is to estimateglobal surface water storage changes (ΔV) in large lakes andreservoirs using a combination of paired water surface elevation (WSE) andwater surface area (WSA) extent products. Specifically, we use data producedby multiple satellite altimetry missions (TOPEX/Poseidon, Jason-1, Jason-2,Jason-3, and Envisat) from 1992 on, with surface extent estimated fromTerra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) from 2000on. We leverage relationships between elevation and surface area (i.e.,hypsometry) to produce estimates of ΔV even during periods wheneither of the variables was not available. This approach is successfulprovided that there are strong relationships between the two variablesduring an overlapping period. Our target is to produce time series ofΔV as well as of WSE and WSA for a set of 347 lakes and reservoirsglobally for the 1992–2018 period. The data sets presented and theirrespective algorithm theoretical basis documents are publicly available anddistributed via the Physical Oceanography Distributed Active Archive Center (PO DAAC; https://podaac.jpl.nasa.gov/, last access: 13 May 2020) of NASA's Jet Propulsion Laboratory.Specifically, the WSE data set is available at https://doi.org/10.5067/UCLRS-GREV2 (Birkett et al., 2019), the WSA dataset is available at https://doi.org/10.5067/UCLRS-AREV2(Khandelwal and Kumar, 2019), and the ΔV data set is available athttps://doi.org/10.5067/UCLRS-STOV2 (Tortini et al., 2019). Therecords we describe represent the most complete global surface water timeseries available from the launch of TOPEX/Poseidon in 1992 (beginning of thesatellite altimetry era) to the near present. The production of long-term,consistent, and calibrated records of surface water cycle variables such as inthe data set presented here is of fundamental importance to baseline futureSWOT products.
