scholarly journals Mass-balance characteristics of arctic glaciers

2005 ◽  
Vol 42 ◽  
pp. 225-229 ◽  
Author(s):  
Roger J. Braithwaite
Keyword(s):  
Mass Balance ◽  
Interannual Variability ◽  
Temperature Variability ◽  
The Arctic ◽  
Annual Precipitation ◽  
Northern Eurasia ◽  
Ice Caps ◽  
Mountain Glaciers ◽  
Arctic Alaska ◽  
Low Sensitivity

AbstractA survey of available mass-balance data shows that glaciers on arctic islands, i.e. mountain glaciers and ice caps in northern Canada, Greenland, Svalbard and the Eurasian islands, share mass-balance characteristics of low annual amplitude and small interannual variability. By contrast, glaciers around the Arctic (e.g. in Alaska, Iceland, mainland Scandinavia and northern Eurasia) can have exceptionally large annual amplitude and interannual variability but otherwise share characteristics with glaciers in lower latitudes. The arctic island glaciers occur in areas with low annual precipitation and high annual temperature variability, i.e. in dry-cold or continental regions. Most glaciers surrounding the Arctic (Alaska, Iceland and Scandinavia) occur in areas with high annual precipitation and low annual temperature variability, i.e. in wet-warm or maritime regions. Earlier mass-balance modelling showed that arctic island glaciers have low sensitivity to temperature changes consistent with their low mass-balance amplitude. However, very large changes in mass balance could occur on arctic island glaciers if the sea ice surrounding the arctic islands were reduced so that the climate of the arctic islands becomes more maritime.

Climate Extremes of the 2019/2020 Winter in Northern Eurasia: Contributions by the Climate Trend and Interannual Variability Related to the Arctic Oscillation

2021 ◽  
pp. 5-16
Author(s):  
V. N. Kryjov ◽  
Keyword(s):  
Interannual Variability ◽  
Arctic Oscillation ◽  
Global Climate ◽  
Linear Trend ◽  
Climate Extremes ◽  
The Arctic ◽  
Northern Eurasia ◽  
Climate Trend ◽  
Temperature And Precipitation ◽  
The Arctic Oscillation

The 2019/2020 wintertime (December–March) anomalies of sea level pressure, temperature, and precipitation are analyzed. The contribution of the 40-year linear trend in these parameters associated with global climate change and of the interannual variability associated with the Arctic Oscillation (AO) is assessed. In the 2019/2020 winter, extreme zonal circulation was observed. The mean wintertime AO index was 2.20, which ranked two for the whole observation period (started in the early 20th century) and was outperformed only by the wintertime index of 1988/1989. It is shown that the main contribution to the 2019/2020 wintertime anomalies was provided by the AO. A noticeable contribution of the trend was observed only in the Arctic. Extreme anomalies over Northern Eurasia were mainly associated with the AO rather than the trend. However, the AO-related anomalies, particularly air temperature anomalies, were developing against the background of the trend-induced increased mean level.

scholarly journals The mass balance of McCall Glacier, Brooks Range, Alaska, U.S.A.; its regional relevance and implications for climate change in the Arctic

1998 ◽  
Vol 44 (147) ◽  
pp. 333-351 ◽  
Author(s):  
B.T. Rabus ◽  
K. A. Echelmeyer
Keyword(s):  
Mass Balance ◽  
The Arctic ◽  
Balance Model ◽  
Mass Balances ◽  
Arctic Alaska ◽  
Low Mass ◽  
Length Changes ◽  
Arctic Glacier ◽  
Long Term Trend

AbstractMcCall Glacier has the only long-term mass-balance record in Arctic-Alaska. Average annual balances over the periods 1958–72 and 1972–93 were –15 and –33cm, respectively; recent annual balances (1993–96) are about –60 cm, and the mass-balance gradient has increased. For an Arctic glacier, with its low mass-exchange rate, this marks a significant negative trend.Recently acquired elevation profiles of McCall Glacier and ten other glaciers within a 30 km radius were compared with topographic maps made in 1956 or 1973. Most of these glaciers had average annual mass balances between –25 and –33 cm, while McCall Glacier averaged –28 cm for 1956–93, indicating that it is representative of the region. In contrast, changes in terminus position for the different glaciers vary markedly. Thus, mass-balance trends in this region cannot be estimated from fractional length changes at time-scales of a few decades.We developed a simple degree-day/accumulation mass-balance model for McCall Glacier. The model was tested using precipitation and radiosonde temperatures from weather stations at Inuvik, Canada, and Barrow, Kaktovik and Fairbanks, Alaska, and was calibrated with the measured balances. The Inuvik data reproduce all measured mass balances of McCall Glacier well and also reproduce the long-term trend towards more negative balances. Data from the other stations do not produce satisfactory model results. We speculate that the Arctic Front, oriented east–west in this region, causes the differences in model results.

scholarly journals Relationships between interannual variability of glacier mass balance and climate

1999 ◽  
Vol 45 (151) ◽  
pp. 456-462 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Yu Zhang
Keyword(s):  
Standard Deviation ◽  
Mass Balance ◽  
Interannual Variability ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
The Arctic ◽  
Glacier Mass Balance ◽  
Strongly Correlated ◽  
Calculated Mass ◽  
The Difference

AbstractThe interannual variability of glacier mass balance is expressed by the standard deviation of net balance, which varies from about ±0.1 to ±1.4 m a−1for a sample of 115 glaciers with at least 5 years of record. The standard deviation of net balance is strongly correlated with the mass-balance amplitude (half the difference between winter and summer balances) for 60 glaciers, so the amplitude can be estimated from net balance standard deviation for the other 55 glaciers where winter and summer balances are unavailable. The observed and calculated mass-balance amplitudes for the 115 glaciers show contrasts between the Arctic and lower latitudes, and between maritime and continental regions. The interannual variability of mass balance means that balances must be measured for at least a few years to determine a statistically reliable mean balance for any glacier. The net balance of the Greenland ice sheet is still not accurately known, but its standard deviation is here estimated to be about ±0.24 m a−1, in agreement with other Arctic glaciers. Mass-balance variability of this magnitude implies that the ice sheet can thicken or thin by several metres over 20–30 years without giving statistically significant evidence of non-zero balance under present climate.

scholarly journals Positive mass balance during the late 20th century on Austfonna, Svalbard, revealed using satellite radar interferometry

2007 ◽  
Vol 46 ◽  
pp. 117-122 ◽  
Author(s):  
Suzanne Bevan ◽  
Adrian Luckman ◽  
Tavi Murray ◽  
Helena Sykes ◽  
Jack Kohler
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Radar Interferometry ◽  
The Arctic ◽  
Late 20Th Century ◽  
Ice Caps ◽  
Ice Cap ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Increasing Temperature

AbstractDetermining whether increasing temperature or precipitation will dominate the cryospheric response to climate change is key to forecasting future sea-level rise. The volume of ice contained in the ice caps and glaciers of the Arctic archipelago of Svalbard is small compared with that of the Greenland or Antarctic ice sheets, but is likely to be affected much more rapidly in the short term by climate change. This study investigates the mass balance of Austfonna, Svalbard’s largest ice cap. Equilibrium-line fluxes for the whole ice cap, and for individual drainage basins, were estimated by combining surface velocities measured using satellite radar interferometry with ice thicknesses derived from radio-echo sounding. These fluxes were compared with balance fluxes to reveal that during the 1990s the total mass balance of the accumulation zone was (5.6±2.0)×108m3 a–1. Three basins in the quiescent phase of their surge cycles contributed 75% of this accumulation. The remaining volume may be attributable either to as yet unidentified surge-type glaciers, or to increased precipitation. This result emphasizes the importance of considering the surge dynamics of glaciers when attempting to draw any conclusions on climate change based on snapshot observations of the cryosphere.

scholarly journals Relationships between interannual variability of glacier mass balance and climate

1999 ◽  
Vol 45 (151) ◽  
pp. 456-462 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Yu Zhang
Keyword(s):  
Standard Deviation ◽  
Mass Balance ◽  
Interannual Variability ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
The Arctic ◽  
Glacier Mass Balance ◽  
Strongly Correlated ◽  
Calculated Mass ◽  
The Difference

AbstractThe interannual variability of glacier mass balance is expressed by the standard deviation of net balance, which varies from about ±0.1 to ±1.4 m a−1 for a sample of 115 glaciers with at least 5 years of record. The standard deviation of net balance is strongly correlated with the mass-balance amplitude (half the difference between winter and summer balances) for 60 glaciers, so the amplitude can be estimated from net balance standard deviation for the other 55 glaciers where winter and summer balances are unavailable. The observed and calculated mass-balance amplitudes for the 115 glaciers show contrasts between the Arctic and lower latitudes, and between maritime and continental regions. The interannual variability of mass balance means that balances must be measured for at least a few years to determine a statistically reliable mean balance for any glacier. The net balance of the Greenland ice sheet is still not accurately known, but its standard deviation is here estimated to be about ±0.24 m a−1, in agreement with other Arctic glaciers. Mass-balance variability of this magnitude implies that the ice sheet can thicken or thin by several metres over 20–30 years without giving statistically significant evidence of non-zero balance under present climate.

The Mass Balance of Circum-Arctic Glaciers and Recent Climate Change

1997 ◽  
Vol 48 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Julian A. Dowdeswell ◽  
Jon Ove Hagen ◽  
Helgi Björnsson ◽  
Andrey F. Glazovsky ◽  
William D. Harrison ◽  
...  
Keyword(s):  
Mass Balance ◽  
Ice Age ◽  
The Arctic ◽  
Surface Mass Balance ◽  
Mass Balances ◽  
Negative Mass ◽  
Surface Mass ◽  
Ice Caps ◽  
Recent Climate ◽  
Arctic Ice

The sum of winter accumulation and summer losses of mass from glaciers and ice sheets (net surface mass balance) varies with changing climate. In the Arctic, glaciers and ice caps, excluding the Greenland Ice Sheet, cover about 275,000 km2of both the widely glacierized archipelagos of the Canadian, Norwegian, and Russian High Arctic and the area north of about 60°N in Alaska, Iceland, and Scandinavia. Since the 1940s, surface mass balance time-series of varying length have been acquired from more than 40 Arctic ice caps and glaciers. Most Arctic glaciers have experienced predominantly negative net surface mass balance over the past few decades. There is no uniform recent trend in mass balance for the entire Arctic, although some regional trends occur. Examples are the increasingly negative mass balances for northern Alaska, due to higher summer temperatures, and increasingly positive mass balances for maritime Scandinavia and Iceland, due to increased winter precipitation. The negative mass balance of most Arctic glaciers may be a response to a step-like warming in the early twentieth century at the termination of the cold Little Ice Age. Arctic ice masses outside Greenland are at present contributing about 0.13 mm yr−1to global sea-level rise.

scholarly journals Static mass-balance sensitivity of Arctic glaciers and ice caps using a degree-day approach

2005 ◽  
Vol 42 ◽  
pp. 217-224 ◽  
Author(s):  
Mattias De Woul ◽  
Regine Hock
Keyword(s):  
Mass Balance ◽  
Temperature Increase ◽  
The Arctic ◽  
Balance Model ◽  
Ice Caps ◽  
Degree Day ◽  
Ice Cap ◽  
Temperature And Precipitation ◽  
Air Temperatures ◽  
Global Sea Level

AbstractFuture climate warming is predicted to be more pronounced in the Arctic where approximately two-thirds of all small glaciers on Earth are located. A simple mass-balance model was applied to 42 glaciers and ice caps north of 60° N to estimate mass-balance sensitivities to a hypothetical climate perturbation. The model is based on daily temperature and precipitation data from climate stations in the vicinity of each glacier and ice cap. A regression analysis was made using a degree-day approach where the annual sum of positive daily air temperatures was correlated to measured summer mass balance, and the total annual snow precipitation was correlated to measured winter mass balance. The net mass-balance sensitivity to a hypothetical temperature increase of +1 K ranged from -0.2 to -2.0 m a-1, and an assumed increase in precipitation of +10% changed the mass balance by <+0.1 to +0.4 m a-1, thus on average offsetting the effect of a temperature increase by approximately 20%. Maritime glaciers showed considerably higher mass-balance sensitivities than continental glaciers, in agreement with similar previous studies. The highest sensitivities were found in Iceland, exceeding those reported in previous studies. Extrapolating our results, glaciers and ice caps north of 60° N are estimated to contribute ∼0.6 mm a–1 K–1 to global sea-level rise. Our results highlight the value of long-term mass-balance records and meteorological records in remote areas.

Reconstruction of Holocene glacier fluctuations at Kongsbreen based on sediments deposited in lake Sarsvatnet, Ossian Sarsfjellet, Svalbard

2020 ◽  
Author(s):  
Eivind W. N. Støren ◽  
Ane Brun Bjerkås ◽  
Jostein Bakke ◽  
Henriette Linge ◽  
William D`Andrea ◽  
...  
Keyword(s):  
Time Perspective ◽  
Ct Scanning ◽  
Radiometric Dating ◽  
The Arctic ◽  
Ice Caps ◽  
Mountain Glaciers ◽  
Temperature And Precipitation ◽  
Climate Indicators ◽  
Seismic Surveying ◽  
Two Parameters

&lt;p&gt;The Arctic is warming twice as fast as the global average, and the melting of mountain glaciers and ice caps has accelerated over the last two decades accompanied by reduced sea ice in the Arctic Ocean. Here we combine sedimentological and geochemical approaches to reconstruct changes in glacier extent at the marine terminating glacier Kongsbreen in order to put present-day climate changes into a longer time perspective. Glaciers are highly sensitive climate indicators as they rapidly respond to variations in summer temperature and precipitation, two parameters that are closely linked to atmospheric dynamics. This climate response is recorded by variations in glacier extent and moraine formation and by variations in glacial erosion and hence sedimentation rates in distal glacier-fed lakes. Lake Sarsvatnet is a threshold-lake that only receive glacial derived sediments when the surface of Kongsbreen crosses a local threshold. When the catchment is ice-free, lake sedimentation rate is lower and dominated by material weathered from the immediate proximity and organic-rich sediments. Based on seismic surveying seven coring sites were selected in three different sub-basins in lake Sarsvatnet. Laboratory analyses, including geochemical measurement by XRF scanning and XRD, CT scanning, grain size and measurements of magnetic proxies, were preformed in order to fingerprint the inorganic sediments. Chronological control is based on radiometric dating (&lt;sup&gt;14&lt;/sup&gt;C, &lt;sup&gt;210&lt;/sup&gt;Pb, and &lt;sup&gt;10&lt;/sup&gt;Be). Erratics (n=3, 125-306 m a.s.l.) indicate ice-free conditions since 13.0&amp;#177;1.1 ka (2&amp;#963;), overlapping with the oldest organic material found in the lake which is 11 860&amp;#177;80 cal. yr BP. Until around 7400 cal. yr BP lake Sarsvatnet is dominated by organic sedimentation. From around 7400 &amp;#8211; 6900 cal. yr BP there is evidence for glacial input into the lake indicating the expansion of Kongsbreen and corresponding to the decline in temperature after the HTM. In the following millennia, and entering the Neoglacial period, there is evidence for mulitiple (~20) decadal to centennial-scale periods of glacier expansion, the most recent dated to AD 1650 marking the onset of glacier build-up towards the LIA maximum. This indicate that the Kongsbreen glacier had short lived expansion periods reaching LIA-like extension already during the middle Holocene, as well as multiple times during the Neoglacial.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Mass change of Arctic ice caps and glaciers: implications of regionalizing elevation changes

2013 ◽  
Vol 7 (6) ◽  
pp. 5889-5920 ◽  
Author(s):  
J. Nilsson ◽  
L. Sandberg Sørensen ◽  
V. R. Barletta ◽  
R. Forsberg
Keyword(s):  
Mass Balance ◽  
Satellite Altimetry ◽  
Mass Change ◽  
The Arctic ◽  
Elevation Change ◽  
Ice Caps ◽  
Annual Variability ◽  
Change Pattern ◽  
Elevation Changes ◽  
Arctic Ice

Abstract. Recent studies have determined mass changes of Arctic ice caps and glaciers from satellite altimetry. Determining regional mass balance of ice caps and glaciers using this technique is inherently difficult due to their size and geometry. Furthermore these studies have mostly relied on one method or the same types of methods to determine the regional mass balance, by extrapolating elevation changes using their relation to elevation. This makes the estimation of mass balance heavily dependent on the method used to regionalize the elevation changes. Left without consideration large discrepancies can arise in the mass change estimates and the interpretation of them. In this study we use Ice, Cloud, and land Elevation Satellite (ICESat) derived elevation changes from 2003–2009 and determine the impact of different regionalizing schemes on the mass change estimates of the Arctic ice caps and glaciers. Four different methods, based on interpolation and extrapolation of the elevation changes were used to quantify this effect on the regional mass changes. Secondly, a statistical criteria was developed to determine the optimum method for each region in order to derive robust mass changes and reduce the need of external validation data. In this study we found that the range or spread of the estimated mass changes, for the different regions, was highly correlated to the inter-annual variability of the elevation changes, driven by the different climatic conditions of the regions. Regions affected by a maritime climate show a large range in estimated values, on average 1.5–2 times larger than the predicted errors. For regions in a continental regime the opposite was observed, and the range of the values lies well inside the error estimates. We also found that the extrapolation methods tend on average to produce more negative values than the interpolation methods and that our four methods do not fully reproduce the original histogram. Instead, they produce more negative distributions than the original which may indicate that previous and these current estimates using ICESat observations might be overestimate by as much as 4–19%, depending on region. This should therefore be taken into account when deriving regional mass balance from satellite altimetry in regions which show high inter-annual variability of elevation changes. In these regions several different independent methods should be used to capture the elevation change pattern and then analyzed to determine the most suitable method. For regions in a continental climate regime, and with low variability of elevation changes, a single method may be sufficient to capture the regional elevation change pattern and hence mass balance.

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