DOI: 10.5061/dryad.h70rxwdj5
title: Greenland mass trends from airborne and satellite altimetry during 2011–2020

description: 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.
description: 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. <em>Sci.
 Adv.</em> <strong>2</strong>, 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.2005.07.027