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Lenaerts JTM, Medley B, van den Broeke MR, Wouters B. Observing and Modeling Ice Sheet Surface Mass Balance. REVIEWS OF GEOPHYSICS (WASHINGTON, D.C. : 1985) 2019; 57:376-420. [PMID: 31598609 PMCID: PMC6774314 DOI: 10.1029/2018rg000622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/17/2019] [Accepted: 03/19/2019] [Indexed: 06/10/2023]
Abstract
Surface mass balance (SMB) provides mass input to the surface of the Antarctic and Greenland Ice Sheets and therefore comprises an important control on ice sheet mass balance and resulting contribution to global sea level change. As ice sheet SMB varies highly across multiple scales of space (meters to hundreds of kilometers) and time (hourly to decadal), it is notoriously challenging to observe and represent in models. In addition, SMB consists of multiple components, all of which depend on complex interactions between the atmosphere and the snow/ice surface, large-scale atmospheric circulation and ocean conditions, and ice sheet topography. In this review, we present the state-of-the-art knowledge and recent advances in ice sheet SMB observations and models, highlight current shortcomings, and propose future directions. Novel observational methods allow mapping SMB across larger areas, longer time periods, and/or at very high (subdaily) temporal frequency. As a recent observational breakthrough, cosmic ray counters provide direct estimates of SMB, circumventing the need for accurate snow density observations upon which many other techniques rely. Regional atmospheric climate models have drastically improved their simulation of ice sheet SMB in the last decade, thanks to the inclusion or improved representation of essential processes (e.g., clouds, blowing snow, and snow albedo), and by enhancing horizontal resolution (5-30 km). Future modeling efforts are required in improving Earth system models to match regional atmospheric climate model performance in simulating ice sheet SMB, and in reinforcing the efforts in developing statistical and dynamic downscaling to represent smaller-scale SMB processes.
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Affiliation(s)
- Jan T. M. Lenaerts
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderCOUSA
| | - Brooke Medley
- Cryospheric Sciences LaboratoryNASA GSFCGoddardMDUSA
| | | | - Bert Wouters
- Institute for Marine and Atmospheric ResearchUtrecht UniversityUtrechtThe Netherlands
- Faculty of Civil Engineering and GeosciencesDelft University of TechnologyDelftThe Netherlands
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Khan SA, Aschwanden A, Bjørk AA, Wahr J, Kjeldsen KK, Kjær KH. Greenland ice sheet mass balance: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2015; 78:046801. [PMID: 25811969 DOI: 10.1088/0034-4885/78/4/046801] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance and to ice discharge, which are forced by internal or external (atmospheric/oceanic/basal) fluctuations. Regardless of the measurement method, observations over the last two decades show an increase in ice loss rate, associated with speeding up of glaciers and enhanced melting. However, both ice discharge and melt-induced mass losses exhibit rapid short-term fluctuations that, when extrapolated into the future, could yield erroneous long-term trends. In this paper we review the GrIS mass loss over more than a century by combining satellite altimetry, airborne altimetry, interferometry, aerial photographs and gravimetry data sets together with modelling studies. We revisit the mass loss of different sectors and show that they manifest quite different sensitivities to atmospheric and oceanic forcing. In addition, we discuss recent progress in constructing coupled ice-ocean-atmosphere models required to project realistic future sea-level changes.
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Affiliation(s)
- Shfaqat A Khan
- DTU Space-National Space Institute, Technical University of Denmark, Department of Geodesy, Kgs. Lyngby, Denmark
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Hakuba MZ, Folini D, Wild M, Schär C. Impact of Greenland's topographic height on precipitation and snow accumulation in idealized simulations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017052] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Humphrey NF, Harper JT, Pfeffer WT. Thermal tracking of meltwater retention in Greenland's accumulation area. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jf002083] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Stibal M, Telling J, Cook J, Mak KM, Hodson A, Anesio AM. Environmental controls on microbial abundance and activity on the greenland ice sheet: a multivariate analysis approach. MICROBIAL ECOLOGY 2012; 63:74-84. [PMID: 21898102 DOI: 10.1007/s00248-011-9935-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 08/22/2011] [Indexed: 05/06/2023]
Abstract
Microbes in supraglacial ecosystems have been proposed to be significant contributors to regional and possibly global carbon cycling, and quantifying the biogeochemical cycling of carbon in glacial ecosystems is of great significance for global carbon flow estimations. Here we present data on microbial abundance and productivity, collected along a transect across the ablation zone of the Greenland ice sheet (GrIS) in summer 2010. We analyse the relationships between the physical, chemical and biological variables using multivariate statistical analysis. Concentrations of debris-bound nutrients increased with distance from the ice sheet margin, as did both cell numbers and activity rates before reaching a peak (photosynthesis) or a plateau (respiration, abundance) between 10 and 20 km from the margin. The results of productivity measurements suggest an overall net autotrophy on the GrIS and support the proposed role of ice sheet ecosystems in carbon cycling as regional sinks of CO(2) and places of production of organic matter that can be a potential source of nutrients for downstream ecosystems. Principal component analysis based on chemical and biological data revealed three clusters of sites, corresponding to three 'glacier ecological zones', confirmed by a redundancy analysis (RDA) using physical data as predictors. RDA using data from the largest 'bare ice zone' showed that glacier surface slope, a proxy for melt water flow, accounted for most of the variation in the data. Variation in the chemical data was fully explainable by the determined physical variables. Abundance of phototrophic microbes and their proportion in the community were identified as significant controls of the carbon cycling-related microbial processes.
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Affiliation(s)
- Marek Stibal
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK.
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Hanna E, Huybrechts P, Cappelen J, Steffen K, Bales RC, Burgess E, McConnell JR, Peder Steffensen J, Van den Broeke M, Wake L, Bigg G, Griffiths M, Savas D. Greenland Ice Sheet surface mass balance 1870 to 2010 based on Twentieth Century Reanalysis, and links with global climate forcing. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016387] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Petersen L, Pellicciotti F. Spatial and temporal variability of air temperature on a melting glacier: Atmospheric controls, extrapolation methods and their effect on melt modeling, Juncal Norte Glacier, Chile. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd015842] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Committed sea-level rise for the next century from Greenland ice sheet dynamics during the past decade. Proc Natl Acad Sci U S A 2011; 108:8978-83. [PMID: 21576500 DOI: 10.1073/pnas.1017313108] [Citation(s) in RCA: 176] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We use a three-dimensional, higher-order ice flow model and a realistic initial condition to simulate dynamic perturbations to the Greenland ice sheet during the last decade and to assess their contribution to sea level by 2100. Starting from our initial condition, we apply a time series of observationally constrained dynamic perturbations at the marine termini of Greenland's three largest outlet glaciers, Jakobshavn Isbræ, Helheim Glacier, and Kangerdlugssuaq Glacier. The initial and long-term diffusive thinning within each glacier catchment is then integrated spatially and temporally to calculate a minimum sea-level contribution of approximately 1 ± 0.4 mm from these three glaciers by 2100. Based on scaling arguments, we extend our modeling to all of Greenland and estimate a minimum dynamic sea-level contribution of approximately 6 ± 2 mm by 2100. This estimate of committed sea-level rise is a minimum because it ignores mass loss due to future changes in ice sheet dynamics or surface mass balance. Importantly, > 75% of this value is from the long-term, diffusive response of the ice sheet, suggesting that the majority of sea-level rise from Greenland dynamics during the past decade is yet to come. Assuming similar and recurring forcing in future decades and a self-similar ice dynamical response, we estimate an upper bound of 45 mm of sea-level rise from Greenland dynamics by 2100. These estimates are constrained by recent observations of dynamic mass loss in Greenland and by realistic model behavior that accounts for both the long-term cumulative mass loss and its decay following episodic boundary forcing.
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Observed Mass Balance of Mountain Glaciers and Greenland Ice Sheet in the 20th Century and the Present Trends. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/978-94-007-2063-3_15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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Andersen ML, Larsen TB, Nettles M, Elosegui P, van As D, Hamilton GS, Stearns LA, Davis JL, Ahlstrøm AP, de Juan J, Ekström G, Stenseng L, Khan SA, Forsberg R, Dahl-Jensen D. Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jf001760] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Murray T, Scharrer K, James TD, Dye SR, Hanna E, Booth AD, Selmes N, Luckman A, Hughes ALC, Cook S, Huybrechts P. Ocean regulation hypothesis for glacier dynamics in southeast Greenland and implications for ice sheet mass changes. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jf001522] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rye CJ, Arnold NS, Willis IC, Kohler J. Modeling the surface mass balance of a high Arctic glacier using the ERA-40 reanalysis. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jf001364] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cameron J. Rye
- Scott Polar Research Institute; University of Cambridge; Cambridge UK
| | - Neil S. Arnold
- Scott Polar Research Institute; University of Cambridge; Cambridge UK
| | - Ian C. Willis
- Scott Polar Research Institute; University of Cambridge; Cambridge UK
| | - Jack Kohler
- Norwegian Polar Institute; Polar Environmental Centre; Tromsø Norway
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Burgess EW, Forster RR, Box JE, Mosley-Thompson E, Bromwich DH, Bales RC, Smith LC. A spatially calibrated model of annual accumulation rate on the Greenland Ice Sheet (1958-2007). ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jf001293] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Evan W. Burgess
- Department of Geography; University of Utah; Salt Lake City Utah USA
| | | | - Jason E. Box
- Department of Geography; Ohio State University; Columbus Ohio USA
- Byrd Polar Research Center; Ohio State University; Columbus Ohio USA
| | - Ellen Mosley-Thompson
- Department of Geography; Ohio State University; Columbus Ohio USA
- Byrd Polar Research Center; Ohio State University; Columbus Ohio USA
| | - David H. Bromwich
- Department of Geography; Ohio State University; Columbus Ohio USA
- Byrd Polar Research Center; Ohio State University; Columbus Ohio USA
| | - Roger C. Bales
- Sierra Nevada Research Institute; University of California; Merced California USA
| | - Laurence C. Smith
- Department of Geography; University of California; Los Angeles California USA
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Hood E, Fellman J, Spencer RGM, Hernes PJ, Edwards R, D'Amore D, Scott D. Glaciers as a source of ancient and labile organic matter to the marine environment. Nature 2010; 462:1044-7. [PMID: 20033045 DOI: 10.1038/nature08580] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 10/02/2009] [Indexed: 11/09/2022]
Abstract
Riverine organic matter supports of the order of one-fifth of estuarine metabolism. Coastal ecosystems are therefore sensitive to alteration of both the quantity and lability of terrigenous dissolved organic matter (DOM) delivered by rivers. The lability of DOM is thought to vary with age, with younger, relatively unaltered organic matter being more easily metabolized by aquatic heterotrophs than older, heavily modified material. This view is developed exclusively from work in watersheds where terrestrial plant and soil sources dominate streamwater DOM. Here we characterize streamwater DOM from 11 coastal watersheds on the Gulf of Alaska that vary widely in glacier coverage (0-64 per cent). In contrast to non-glacial rivers, we find that the bioavailability of DOM to marine microorganisms is significantly correlated with increasing (14)C age. Moreover, the most heavily glaciated watersheds are the source of the oldest ( approximately 4 kyr (14)C age) and most labile (66 per cent bioavailable) DOM. These glacial watersheds have extreme runoff rates, in part because they are subject to some of the highest rates of glacier volume loss on Earth. We estimate the cumulative flux of dissolved organic carbon derived from glaciers contributing runoff to the Gulf of Alaska at 0.13 +/- 0.01 Tg yr(-1) (1 Tg = 10(12) g), of which approximately 0.10 Tg is highly labile. This indicates that glacial runoff is a quantitatively important source of labile reduced carbon to marine ecosystems. Moreover, because glaciers and ice sheets represent the second largest reservoir of water in the global hydrologic system, our findings indicate that climatically driven changes in glacier volume could alter the age, quantity and reactivity of DOM entering coastal oceans.
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Affiliation(s)
- Eran Hood
- Environmental Science and Geography Program, University of Alaska Southeast, Juneau, Alaska 99801, USA.
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Bingham RG, Hubbard AL, Nienow PW, Sharp MJ. An investigation into the mechanisms controlling seasonal speedup events at a High Arctic glacier. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jf000832] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Sodemann H, Schwierz C, Wernli H. Interannual variability of Greenland winter precipitation sources: Lagrangian moisture diagnostic and North Atlantic Oscillation influence. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd008503] [Citation(s) in RCA: 217] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Luthcke SB, Zwally HJ, Abdalati W, Rowlands DD, Ray RD, Nerem RS, Lemoine FG, McCarthy JJ, Chinn DS. Recent Greenland Ice Mass Loss by Drainage System from Satellite Gravity Observations. Science 2006; 314:1286-9. [PMID: 17053112 DOI: 10.1126/science.1130776] [Citation(s) in RCA: 308] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Mass changes of the Greenland Ice Sheet resolved by drainage system regions were derived from a local mass concentration analysis of NASA-Deutsches Zentrum für Luftund Raumfahrt Gravity Recovery and Climate Experiment (GRACE mission) observations. From 2003 to 2005, the ice sheet lost 101 +/- 16 gigaton/year, with a gain of 54 gigaton/year above 2000 meters and a loss of 155 gigaton/year at lower elevations. The lower elevations show a large seasonal cycle, with mass losses during summer melting followed by gains from fall through spring. The overall rate of loss reflects a considerable change in trend (-113 +/- 17 gigaton/year) from a near balance during the 1990s but is smaller than some other recent estimates.
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Affiliation(s)
- S B Luthcke
- Planetary Geodynamics Laboratory, Code 698, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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Gregory JM, Huybrechts P. Ice-sheet contributions to future sea-level change. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2006; 364:1709-31. [PMID: 16782607 DOI: 10.1098/rsta.2006.1796] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Accurate simulation of ice-sheet surface mass balance requires higher spatial resolution than is afforded by typical atmosphere-ocean general circulation models (AOGCMs), owing, in particular, to the need to resolve the narrow and steep margins where the majority of precipitation and ablation occurs. We have developed a method for calculating mass-balance changes by combining ice-sheet average time-series from AOGCM projections for future centuries, both with information from high-resolution climate models run for short periods and with a 20km ice-sheet mass-balance model. Antarctica contributes negatively to sea level on account of increased accumulation, while Greenland contributes positively because ablation increases more rapidly. The uncertainty in the results is about 20% for Antarctica and 35% for Greenland. Changes in ice-sheet topography and dynamics are not included, but we discuss their possible effects. For an annual- and area-average warming exceeding 4.5+/-0.9K in Greenland and 3.1+/-0.8K in the global average, the net surface mass balance of the Greenland ice sheet becomes negative, in which case it is likely that the ice sheet would eventually be eliminated, raising global-average sea level by 7m.
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Affiliation(s)
- J M Gregory
- University of Reading, Department of Meteorology, Centre for Global Atmospheric Modelling, UK
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Affiliation(s)
- Julian A Dowdeswell
- Scott Polar Research Institute, University of Cambridge, Cambridge CB2 1ER, UK.
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Bougamont M, Bamber JL, Greuell W. A surface mass balance model for the Greenland Ice Sheet. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jf000348] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marion Bougamont
- School of Geographical Sciences; University of Bristol; Bristol UK
| | | | - Wouter Greuell
- Institute for Marine and Atmospheric Research Utrecht (IMAU); Utrecht University; Utrecht Netherlands
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Abstract
Future sea-level rise is an important issue related to the continuing buildup of atmospheric greenhouse gas concentrations. The Greenland and Antarctic ice sheets, with the potential to raise sea level approximately 70 meters if completely melted, dominate uncertainties in projected sea-level change. Freshwater fluxes from these ice sheets also may affect oceanic circulation, contributing to climate change. Observational and modeling advances have reduced many uncertainties related to ice-sheet behavior, but recently detected, rapid ice-marginal changes contributing to sea-level rise may indicate greater ice-sheet sensitivity to warming than previously considered.
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Affiliation(s)
- Richard B Alley
- Department of Geosciences and Earth and Environmental Systems Institute, Pennsylvania State University, Deike Building, University Park, PA 16802, USA.
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Johannessen OM, Khvorostovsky K, Miles MW, Bobylev LP. Recent ice-sheet growth in the interior of Greenland. Science 2005; 310:1013-6. [PMID: 16239440 DOI: 10.1126/science.1115356] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A continuous data set of Greenland Ice Sheet altimeter height from European Remote Sensing satellites (ERS-1 and ERS-2), 1992 to 2003, has been analyzed. An increase of 6.4 +/- 0.2 centimeters per year (cm/year) is found in the vast interior areas above 1500 meters, in contrast to previous reports of high-elevation balance. Below 1500 meters, the elevation-change rate is -2.0 +/- 0.9 cm/year, in qualitative agreement with reported thinning in the ice-sheet margins. Averaged over the study area, the increase is 5.4 +/- 0.2 cm/year, or approximately 60 cm over 11 years, or approximately 54 cm when corrected for isostatic uplift. Winter elevation changes are shown to be linked to the North Atlantic Oscillation.
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Affiliation(s)
- Ola M Johannessen
- Mohn-Sverdrup Center for Global Ocean Studies and Operational Oceanography, Nansen Environmental and Remote Sensing Center, Bergen, 5006, Norway.
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