scholarly journals Recent variations in surface mass balance of the Antarctic Peninsula ice sheet

2004 ◽  
Vol 50 (169) ◽  
pp. 257-267 ◽  
Author(s):  
Elizabeth M. Morris ◽  
Robert Mulvaney
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Air Temperature ◽  
Antarctic Peninsula ◽  
Empirical Relation ◽  
Surface Air Temperature ◽  
Climatic Conditions ◽  
Temperature Record ◽  
Surface Mass ◽  
The Antarctic

AbstractOver the period 1972–98 the height of the snow surface at eight Antarctic sites in Palmer Land and on Alexander Island has been measured with respect to fixed points on local nunataks. From these data an empirical relation between height changes over a given period and three key variables has been derived. These variables are (i) the local mean annual surface air temperature, (ii) a regional estimate of energy available for melt over the period (derived from the nearby Rothera air-temperature record) and (iii) a regional estimate of accumulation over the period (derived from the nearby Gomez Nunatak ice-core accumulation record). Using this relation, the contribution of the Antarctic Peninsula to sea-level rise for warming from climatic conditions (averaged over the last 30 years) is estimated to be −0.006 ± 0.002 mm a−1 K−1. If recent warm conditions persist, however, and meltwater can run off to the sea, the contribution to sea-level rise from ablation is calculated to be 0.07 ± 0.02 mm a−1 K−1.

scholarly journals Northern Hemisphere Glacier and Ice Cap Surface Mass Balance and Contribution to Sea Level Rise

2014 ◽  
Vol 27 (15) ◽  
pp. 6051-6073 ◽  
Author(s):  
Sebastian H. Mernild ◽  
Glen E. Liston ◽  
Christopher A. Hiemstra
Keyword(s):  
Mass Balance ◽  
Sea Level Rise ◽  
Sea Level ◽  
Northern Hemisphere ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Greenland Ice Sheet ◽  
Surface Mass Balance ◽  
Time Step ◽  
Surface Mass

Abstract Mass changes and mass contribution to sea level rise from glaciers and ice caps (GIC) are key components of the earth’s changing sea level. GIC surface mass balance (SMB) magnitudes and individual and regional mean conditions and trends (1979–2009) were simulated for all GIC having areas greater or equal to 0.5 km2 in the Northern Hemisphere north of 25°N latitude (excluding the Greenland Ice Sheet). Recent datasets, including the Randolph Glacier Inventory (RGI; v. 2.0), the NOAA Global Land One-km Base Elevation Project (GLOBE), and the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) products, together with recent SnowModel developments, allowed relatively high-resolution (1-km horizontal grid; 3-h time step) simulations of GIC surface air temperature, precipitation, sublimation, evaporation, surface runoff, and SMB. Simulated SMB outputs were calibrated against 1422 direct glaciological annual SMB observations of 78 GIC. The overall GIC mean annual and mean summer air temperature, runoff, and SMB loss increased during the simulation period. The cumulative GIC SMB was negative for all regions. The SMB contribution to sea level rise was largest from Alaska and smallest from the Caucasus. On average, the contribution to sea level rise was 0.51 ± 0.16 mm sea level equivalent (SLE) yr−1 for 1979–2009 and ~40% higher 0.71 ± 0.15 mm SLE yr−1 for the last decade, 1999–2009.

scholarly journals Future sea-level rise from tidewater and ice-shelf tributary glaciers of the Antarctic Peninsula

2016 ◽  
Vol 453 ◽  
pp. 161-170 ◽  
Author(s):  
Clemens Schannwell ◽  
Nicholas E. Barrand ◽  
Valentina Radić
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Antarctic Peninsula ◽  
Ice Shelf ◽  
The Antarctic

scholarly journals Diverging future surface mass balance between the Antarctic ice shelves and grounded ice sheet

2021 ◽  
Vol 15 (3) ◽  
pp. 1215-1236
Author(s):  
Christoph Kittel ◽  
Charles Amory ◽  
Cécile Agosta ◽  
Nicolas C. Jourdain ◽  
Stefan Hofer ◽  
...  
Keyword(s):  
Mass Balance ◽  
Sea Level Rise ◽  
Sea Level ◽  
Ice Sheet ◽  
Surface Mass Balance ◽  
Near Surface ◽  
Surface Mass ◽  
Ice Shelves ◽  
Run Off ◽  
The Antarctic

Abstract. The future surface mass balance (SMB) will influence the ice dynamics and the contribution of the Antarctic ice sheet (AIS) to the sea level rise. Most of recent Antarctic SMB projections were based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5). However, new CMIP6 results have revealed a +1.3 ∘C higher mean Antarctic near-surface temperature than in CMIP5 at the end of the 21st century, enabling estimations of future SMB in warmer climates. Here, we investigate the AIS sensitivity to different warmings with an ensemble of four simulations performed with the polar regional climate model Modèle Atmosphérique Régional (MAR) forced by two CMIP5 and two CMIP6 models over 1981–2100. Statistical extrapolation enables us to expand our results to the whole CMIP5 and CMIP6 ensembles. Our results highlight a contrasting effect on the future grounded ice sheet and the ice shelves. The SMB over grounded ice is projected to increase as a response to stronger snowfall, only partly offset by enhanced meltwater run-off. This leads to a cumulated sea-level-rise mitigation (i.e. an increase in surface mass) of the grounded Antarctic surface by 5.1 ± 1.9 cm sea level equivalent (SLE) in CMIP5-RCP8.5 (Relative Concentration Pathway 8.5) and 6.3 ± 2.0 cm SLE in CMIP6-ssp585 (Shared Socioeconomic Pathways 585). Additionally, the CMIP6 low-emission ssp126 and intermediate-emission ssp245 scenarios project a stabilized surface mass gain, resulting in a lower mitigation to sea level rise than in ssp585. Over the ice shelves, the strong run-off increase associated with higher temperature is projected to decrease the SMB (more strongly in CMIP6-ssp585 compared to CMIP5-RCP8.5). Ice shelves are however predicted to have a close-to-present-equilibrium stable SMB under CMIP6 ssp126 and ssp245 scenarios. Future uncertainties are mainly due to the sensitivity to anthropogenic forcing and the timing of the projected warming. While ice shelves should remain at a close-to-equilibrium stable SMB under the Paris Agreement, MAR projects strong SMB decrease for an Antarctic near-surface warming above +2.5 ∘C compared to 1981–2010 mean temperature, limiting the warming range before potential irreversible damages on the ice shelves. Finally, our results reveal the existence of a potential threshold (+7.5 ∘C) that leads to a lower grounded-SMB increase. This however has to be confirmed in following studies using more extreme or longer future scenarios.

scholarly journals Long-Term Climate Change Commitment and Reversibility: An EMIC Intercomparison

2013 ◽  
Vol 26 (16) ◽  
pp. 5782-5809 ◽  
Author(s):  
Kirsten Zickfeld ◽  
Michael Eby ◽  
Andrew J. Weaver ◽  
Kaitlin Alexander ◽  
Elisabeth Crespin ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
Co2 Emissions ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Meridional Overturning Circulation ◽  
Atmospheric Co2 ◽  
Change Commitment

Abstract This paper summarizes the results of an intercomparison project with Earth System Models of Intermediate Complexity (EMICs) undertaken in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). The focus is on long-term climate projections designed to 1) quantify the climate change commitment of different radiative forcing trajectories and 2) explore the extent to which climate change is reversible on human time scales. All commitment simulations follow the four representative concentration pathways (RCPs) and their extensions to year 2300. Most EMICs simulate substantial surface air temperature and thermosteric sea level rise commitment following stabilization of the atmospheric composition at year-2300 levels. The meridional overturning circulation (MOC) is weakened temporarily and recovers to near-preindustrial values in most models for RCPs 2.6–6.0. The MOC weakening is more persistent for RCP8.5. Elimination of anthropogenic CO2 emissions after 2300 results in slowly decreasing atmospheric CO2 concentrations. At year 3000 atmospheric CO2 is still at more than half its year-2300 level in all EMICs for RCPs 4.5–8.5. Surface air temperature remains constant or decreases slightly and thermosteric sea level rise continues for centuries after elimination of CO2 emissions in all EMICs. Restoration of atmospheric CO2 from RCP to preindustrial levels over 100–1000 years requires large artificial removal of CO2 from the atmosphere and does not result in the simultaneous return to preindustrial climate conditions, as surface air temperature and sea level response exhibit a substantial time lag relative to atmospheric CO2.

An analysis of a 34-year air temperature record from Fossil Bluff (71°S, 68°W), Antarctica

1997 ◽  
Vol 9 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Stephen A. Harangozo ◽  
Steven R. Colwell ◽  
John C. King
Keyword(s):  
Air Temperature ◽  
Antarctic Peninsula ◽  
Surface Air Temperature ◽  
Temperature Record ◽  
West Antarctic ◽  
Air Temperatures ◽  
Marguerite Bay ◽  
First Time ◽  
Snow Temperature

An analysis of a long-term surface air temperature record for Fossil Bluff in the George VI Sound, West Antarctic Peninsula (WAP) documents in detail some important aspects of the climate of this area for the first time. The analysis identifies the close dependency of air temperatures on latitude in the WAP but reveals that the strength of this dependency is greatest in winter. This result along with others leads to the Fossil Bluff climate regime being characterized as ‘continental’ rather than ‘maritime’ as found further north. The WAP as a whole displays large interannual temperature variability but this is greatest in Marguerite Bay rather than the Fossil Bluff area. Evidence is also provided for secular climatic change appearing in summer throughout the WAP over the last few decades. The representativeness of existing Antarctic Peninsula annual air temperature climatologies, based mainly on snow temperature measurements, for the winter and summer periods is also noted.

scholarly journals A complete glacier inventory of the Antarctic Peninsula based on Landsat 7 images from 2000 to 2002 and other preexisting data sets

2017 ◽  
Vol 9 (1) ◽  
pp. 115-131 ◽  
Author(s):  
Jacqueline Huber ◽  
Alison J. Cook ◽  
Frank Paul ◽  
Michael Zemp
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Antarctic Peninsula ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Data Sets ◽  
Rock Outcrops ◽  
Data Set ◽  
Glacier Inventory ◽  
The Antarctic

Abstract. The glaciers on the Antarctic Peninsula (AP) potentially make a large contribution to sea level rise. However, this contribution has been difficult to estimate since no complete glacier inventory (outlines, attributes, separation from the ice sheet) is available. This work fills the gap and presents a new glacier inventory of the AP north of 70° S, based on digitally combining preexisting data sets with geographic information system (GIS) techniques. Rock outcrops have been removed from the glacier basin outlines of Cook et al. (2014) by intersection with the latest layer of the Antarctic Digital Database (Burton-Johnson et al., 2016). Glacier-specific topographic parameters (e.g., mean elevation, slope and aspect) as well as hypsometry have been calculated from the DEM of Cook et al. (2012). We also assigned connectivity levels to all glaciers following the concept by Rastner et al. (2012). Moreover, the bedrock data set of Huss and Farinotti (2014) enabled us to add ice thickness and volume for each glacier. The new inventory is available from the Global Land Ice Measurements from Space (GLIMS) database (doi:10.7265/N5V98602) and consists of 1589 glaciers covering an area of 95 273 km2, slightly more than the 89 720 km2 covered by glaciers surrounding the Greenland Ice Sheet. Hence, compared to the preexisting data set of Cook et al. (2014), this data set covers a smaller area and one glacier less due to the intersection with the rock outcrop data set. The total estimated ice volume is 34 590 km3, of which one-third is below sea level. The hypsometric curve has a bimodal shape due to the unique topography of the AP, which consists mainly of ice caps with outlet glaciers. Most of the glacierized area is located at 200–500 m a.s.l., with a secondary maximum at 1500–1900 m. Approximately 63 % of the area is drained by marine-terminating glaciers, and ice-shelf tributary glaciers cover 35 % of the area. This combination indicates a high sensitivity of the glaciers to climate change for several reasons: (1) only slightly rising equilibrium-line altitudes would expose huge additional areas to ablation, (2) rising ocean temperatures increase melting of marine terminating glaciers, and (3) ice shelves have a buttressing effect on their feeding glaciers and their collapse would alter glacier dynamics and strongly enhance ice loss (Rott et al., 2011). The new inventory should facilitate modeling of the related effects using approaches tailored to glaciers for a more accurate determination of their future evolution and contribution to sea level rise.

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