Greenland mass trends from airborne and satellite altimetry during 2011–2020

We use satellite and airborne altimetry to estimate annual mass changes of the Greenland Ice Sheet. We estimate ice loss corresponding to a sea-level rise of 6.9±0.4 millimeters from April 2011 to April 2020, with the highest annual ice loss rate of 1.4 mm/yr sea-level equivalent from April 2019 to April 2020. On a regional scale, our annual mass loss timeseries reveals 10-15 m/yr dynamic thickening at the terminus of Jakobshavn Isbræ from April 2016 to April 2018, followed by a return to dynamic thinning. We observe contrasting patterns of mass loss acceleration in different basins across the ice sheet. Our gridded satellite altimetry data and surface mass balance (SMB), along with corrections due to firn compaction are available for download. Here, we provide: (1) Annual (April to April) elevation change rates of the Greenland Ice Sheet from April 2011 to April 2020 from CryoSat-2, ICESat-2 and NASA's ATM flights. 1x1 km grid. (2) Annual (April to April) elevation change rates due to SMB anomalies. 1x1 km grid. (3) Ice-sheet wide annual corrections due to firn compaction.Funding provided by: Danmarks Frie ForskningsfondCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004836Award Number: 1026-00085BFunding provided by: H2020 European Research CouncilAward Number: 694188 (GlobalMass)We have used radar altimetry data from ESA's Earth Explorer CryoSat-2 mission (Wingham et al., 2006) to estimate annual mass changes of the GrIS from April 2011 to April 2020. We supplemented CryoSat-2 data with laser altimetry observations from NASA's Operation IceBridge Airborne Topographic Mapper (ATM) flights from April 2011 to April 2019 (Studinger et al., 2020). NASA ended its Operation IceBridge measurement over Greenland in spring 2019, so to fill the gap in laser altimetry data, we used Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) data from April 2019 to April 2020. We applied corrections for the Earth's immediate elastic response to contemporary ice mass changes and a correction for glacial isostatic adjustment (GIA) using a recent model entitled "GNET-GIA" (Khan et al., 2016). We converted the observed ice volume changes to mass changes and considered firn compaction obtained using the Regional Atmospheric Climate Model (RACMO2.3p2) (Ligtenberg et al., 2018). Khan, S. A. et al. (2016). Geodetic measurements reveal similarities between post-Last Glacial Maximum and present-day mass loss from the Greenland ice sheet. Sci. Adv. 2, e1600931, https://doi.org/10.1126/sciadv.1600931 Ligtenberg, S. R. M., Kuipers Munneke, P., Noël, B. P. Y., and van den Broeke, M. R. (2018). Brief communication: Improved simulation of the present-day Greenland firn layer (1960–2016), The Cryosphere, 12, 1643–1649, https://doi.org/10.5194/tc-12-1643-2018. Studinger, M. (2014), updated 2020. IceBridge ATM L2 Icessn Elevation, Slope, and Roughness, Version 2. [2011-2019]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center, https://doi.org/10.5067/CPRXXK3F39RV Wingham, D. J., Francis, C. R., Baker, S., Bouzinac, C., Brockley, D., et al. (2006). CryoSat: A mission to 705 determine the fluctuations in Earth's land and marine ice fields. In M. Singh, RP and Shea (Ed.), Natural Hazards and Oceanographic processes from satellite data, 37, pp. 841–871. Elsevier science ltd. https://doi.org/10.1016/j.asr.2005.07.02