ICESat-2 land ice products resolve Greenland and Antarctic ice-sheet height changes on seasonal to multiyear time scales

Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine

NASA’s ICESat-2 mission was launched in 2018, carrying a photon-counting laser altimeter, with a primary objective of measuring height changes across Earth’s surface. ICESat-2 has provided measurements of ice surface height between 88º N and S, repeated four times per year, with high vertical accuracy and along-track spatial resolution. Its accuracy and coverage has enabled near-complete recovery of height changes across the ice sheets, capturing subtle changes in the interior, and rapid changes along the dynamic margins with steep slopes and the floating peripheral ice shelves. The ICESat-2 Science Team has developed a suite of algorithms that produce along-track and gridded land ice height products at various levels of processing, all freely available at the National Snow and Ice Data Center. Here, we describe three higher-level land-ice data products derived from ATL06 and their underlying algorithms: along-track height change (ATL11), digital elevation model (ATL14) and gridded surface height change (ATL15). We demonstrate the suitability of each data product for studying different ice sheet regions. We then show height changes for Greenland and Antarctica from ATL15 during the first 6 years of the ICESat-2 mission (October 2018–December 2024), illustrating how ICESat-2 measurements can distinguish the multi-year trends from seasonal fluctuations.