Continuity of the Mass Loss of the World's Glaciers and Ice Caps From the GRACE and GRACE Follow‐On Missions. Issue 9 (30th April 2020)

• Record Type: Journal Article
• Authors: Ciracì, E.; Velicogna, I.; Swenson, S.
• Is Part Of: Geophysical research letters. Volume 47:Issue 9(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-30
• Subjects: gravity -- glacier -- sea level -- climate model -- hydrology -- freshwater; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2019GL086926
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We use time series of time‐variable gravity from the Gravitational Recovery and Climate Experiment (GRACE) and GRACE Follow‐On (GRACE‐FO) missions to evaluate the mass balance of the world's glaciers and ice caps (GIC) for the time period April 2002 to September 2019, excluding Antarctica and Greenland peripheral glaciers. We demonstrate continuity of the mass balance record across the GRACE/GRACE‐FO data gap using independent data from the GMAO Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2) reanalysis. We report an average mass loss of 281.5 ± 30 Gt/yr, an acceleration of 50 ± 20 Gt/yr per decade, and a 13‐mm cumulative sea level rise for the analyzed period. Seven regions dominate the mass loss, with the largest share from the Arctic: Alaska (72.5 ± 8 Gt/yr), Canadian Arctic Archipelago (73.0 ± 9 Gt/yr), Southern Andes (30.4 ± 13 Gt/yr), High Mountain Asia (HMA) (28.8 ± 11 Gt/yr), Russian Arctic (20.2 ± 6 Gt/yr), Iceland (15.9 ± 4 Gt/yr), and Svalbard (12.1 ± 4 Gt/yr). At the regional level, the analysis of acceleration is complicated by a strong interannual to decadal variability in mass balance that is well reproduced by the GRACE‐calibrated MERRA‐2 data. Plain Language Summary: We employ data from two consecutive spaceborne missions, Gravitational Recovery and Climate Experiment (GRACE) and GRACE Follow‐On (GRACE‐FO), that track changes in the gravity field of the Earth to quantify the mass loss of all of the GIC outside Greenland and Antarctica. We demonstrate data continuity across the 1 yr and a half data gap between the two missions using independent data from the NASA Global Modeling and Assimilation Office's Modern‐Era Retrospective Analysis for Research and Applications, Version 2 (MERRA‐2) reanalysis. We report an average mass loss of 281.5 Gt/yr, or 13 mm of sea level rise equivalent in 17.33 yr. The observational record reveals an acceleration in the rate of melt of glaciers and ice caps equivalent to adding an extra 0.14‐mm sea level rise every decade. Key Points: We demonstrate data continuity of the GRACE and GRACE‐FO missions for the world's glaciers and ice caps mass balance using independent data We report an acceleration in mass loss from the glaciers and ice caps during the GRACE/GRACE‐FO time period Glaciers and ice caps contributed 281.5‐Gt/yr mass loss over the last 17.33 yr or 13 mm of global sea level rise