scholarly journals Changes in mountain glaciers and ice caps during the 20th century

2006 ◽  
Vol 43 ◽  
pp. 361-368 ◽  
Author(s):  
Atsumu Ohmura
Keyword(s):  
Mass Balance ◽  
20Th Century ◽  
Hydrological Cycle ◽  
Dominant Role ◽  
Climatic Conditions ◽  
Melt Temperature ◽  
Average Mass ◽  
Mountain Glaciers ◽  
The Mean

AbstractThe global mass balance of the glaciers outside Greenland and Antarctica is evaluated based on long-term mass-balance observations on 75 glaciers. The cause of the mass-balance change is investigated by examining winter and summer balances from 34 glaciers. The main finding is a common development in mass-balance changes shared by a number of glaciers separated by large distances and climatic conditions. The average mass balance for the second half of the 20th century was negative at –270 to –280 mma−1. The negative mass balance was found to be intensified at –10mm a−2. Increasing summer melt plays a dominant role in determining the long-term trend in mass balance. During the same period the mean winter mass balance increased slightly, indicating an acceleration (3 mma−2) of the hydrological cycle. On some Scandinavian glaciers the mean mass balance was not only positive but its tendency was accelerating. This trend is due to the strong precipitation increase in the last four decades. The melt/temperature relationships for the two warmer periods in the 20th century, one centred around the 1940s and the other ongoing, are different. Reduced melt in the modern warm period, in comparison with the earlier warm phase of the 1940s, is caused by the global dimming which reduced the solar radiation at the Earth’s surface during the second half of the 20th century.

Recent changes of McCall Glacier, Alaska

1995 ◽  
Vol 21 ◽  
pp. 231-239 ◽  
Author(s):  
Bernhard Rabus ◽  
Keith Echelmeyer ◽  
Dennis Trabant ◽  
Carl Benson
Keyword(s):  
Climate Change ◽  
Exchange Rate ◽  
Mass Balance ◽  
Volume Loss ◽  
Average Mass ◽  
Ice Surface ◽  
Low Mass ◽  
The Mean ◽  
Alaskan Arctic ◽  
Drop Rate

Detailed surveys of McCall Glacier in the Alaskan Arctic reveal changes from 1972 to 1993. The ice surface dropped everywhere, by amounts ranging from about 3 m in the highest cirques tq more than 42 m near the present terminus. The total volume loss was 3.5+ 0.2 x 10' m(, resulting in an average mass balance of 0.33 + 0.01 in a . l he terminus has retreated by about 285 m at a rale of 12_.5 ma \ Results from photogrammetry for an earlier period, 1958-71, were I.16x 10'm3 and 0.13 ma for volume change and mass balance, respectively; the mean terminus retreat rate was then 5.7 m a . The changes have to be seen in the context of McCall Glacier’s low mass-exchange rate; annual accumulation and ablation, averaged over the years 1969 72 were only +0.16 and 0.3 m a '. Cross-profiles in the ablation area, surveyed at intervals of a few years, show an increased drop rate since the late 1970s. 7 he volume-ehange data suggest a climate warming in the early 1970s. Enhanced thinning of the lower ablation region and accelerated terminus retreat seem to lag this climate change by not more than 10 years, This indicates a reaction time of McCall Glacier that is considerably shorter than its theoretic response time of about 50 70 years.

scholarly journals Mass balance of Trambau Glacier, Rolwaling region, Nepal Himalaya: in-situ observations, long-term reconstruction and mass-balance sensitivity

2019 ◽  
Vol 65 (252) ◽  
pp. 605-616 ◽  
Author(s):  
SOJIRO SUNAKO ◽  
KOJI FUJITA ◽  
AKIKO SAKAI ◽  
RIJAN B. KAYASTHA
Keyword(s):  
Mass Balance ◽  
High Elevation ◽  
Climatic Conditions ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Balance Study ◽  
Nepal Himalaya ◽  
In Situ Data

ABSTRACTWe conducted a mass-balance study of debris-free Trambau Glacier in the Rolwaling region, Nepal Himalaya, which is accessible to 6000 m a.s.l., to better understand mass-balance processes and the effect of precipitation on these processes on high-elevation Himalayan glaciers. Continuous in situ meteorological and mass-balance observations that spanned the three melt seasons from May 2016 are reported. An energy- and mass-balance model is also applied to evaluate its performance and sensitivity to various climatic conditions. Glacier-wide mass balances ranging from −0.34 ± 0.38 m w.e. in 2016 to −0.82 ± 0.53 m w.e. in 2017/18 are obtained by combining the observations with model results for the areas above the highest stake. The estimated long-term glacier mass balance, which is reconstructed using the ERA-Interim data calibrated with in situ data, is −0.65 ± 0.39 m w.e. a−1for the 1980–2018 period. A significant correlation with annual precipitation (r= 0.77,p< 0.001) is observed, whereas there is no discernible correlation with summer mean air temperature. The results indicate the continuous mass loss of Trambau Glacier over the last four decades, which contrasts with the neighbouring Mera Glacier in balance.

scholarly journals Decay of a long-term monitored glacier: Careser Glacier (Ortles-Cevedale, European Alps)

2013 ◽  
Vol 7 (6) ◽  
pp. 1819-1838 ◽  
Author(s):  
L. Carturan ◽  
C. Baroni ◽  
M. Becker ◽  
A. Bellin ◽  
O. Cainelli ◽  
...  
Keyword(s):  
Mass Loss ◽  
Mass Balance ◽  
Mass Loss Rate ◽  
Regional Scale ◽  
European Alps ◽  
Systematic Observation ◽  
Average Mass ◽  
Observation Series ◽  
The 19Th Century

Abstract. The continuation of valuable, long-term glacier observation series is threatened by the accelerated mass loss which currently affects a large portion of so-called "benchmark" glaciers. In this work we present the evolution of the Careser Glacier, from the beginning of systematic observation at the end of the 19th century to its current condition in 2012. In addition to having one of the longest and richest observation records among the Italian glaciers, Careser is unique in the Italian Alps for its 46 yr mass balance series that started in 1967. In the present study, variations in the length, area and volume of the glacier since 1897 are examined, updating and validating the series of direct mass balance observations and adding to the mass balance record into the past using the geodetic method. The glacier is currently strongly out of balance and in rapid decay; its average mass loss rate over the last 3 decades was 1.5 m water equivalent per year, increasing to 2.0 m water equivalent per year in the last decade. Although these rates are not representative at a regional scale, year-to-year variations in mass balance show an unexpected increase in correlation with other glaciers in the Alps, during the last 3 decades. If mass loss continues at this pace, the glacier will disappear within a few decades, putting an end to this unique observation series.

scholarly journals Reconstruction of the Historical (1750–2020) Mass Balance of Bordu, Kara-Batkak and Sary-Tor Glaciers in the Inner Tien Shan, Kyrgyzstan

2021 ◽  
Vol 9 ◽  
Author(s):  
Lander Van Tricht ◽  
Chloë Marie Paice ◽  
Oleg Rybak ◽  
Rysbek Satylkanov ◽  
Victor Popovnin ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Climatic Conditions ◽  
Tien Shan ◽  
Ice Age ◽  
Balance Model ◽  
Mass Balances ◽  
Specific Mass ◽  
The Future ◽  
The Mean

The mean specific mass balance of a glacier represents the direct link between a glacier and the local climate. Hence, it is intensively monitored throughout the world. In the Kyrgyz Tien Shan, glaciers are of crucial importance with regard to water supply for the surrounding areas. It is therefore essential to know how these glaciers behave due to climate change and how they will evolve in the future. In the Soviet era, multiple glaciological monitoring programs were initiated but these were abandoned in the nineties. Recently, they have been re-established on several glaciers. In this study, a reconstruction of the mean specific mass balance of Bordu, Kara-Batkak and Sary-Tor glaciers is obtained using a surface energy mass balance model. The model is driven by temperature and precipitation data acquired by combining multiple datasets from meteorological stations in the vicinity of the glaciers and tree rings in the Kyrgyz Tien Shan between 1750 and 2020. Multi-annual mass balance measurements integrated over elevation bands of 100 m between 2013 and 2020 are used for calibration. A comparison with WGMS data for the second half of the 20th century is performed for Kara-Batkak glacier. The cumulative mass balances are also compared with geodetic mass balances reconstructed for different time periods. Generally, we find a close agreement, indicating a high confidence in the created mass balance series. The last 20 years show a negative mean specific mass balance except for 2008–2009 when a slightly positive mass balance was found. This indicates that the glaciers are currently in imbalance with the present climatic conditions in the area. For the reconstruction back to 1750, this study specifically highlights that it is essential to adapt the glacier geometry since the end of the Little Ice Age in order to not over- or underestimate the mean specific mass balance. The datasets created can be used to get a better insight into how climate change affects glaciers in the Inner Tien Shan and to model the future evolution of these glaciers as well as other glaciers in the region.

scholarly journals Sensitivity to climate change of the mass balance of glaciers in southern Norway

1993 ◽  
Vol 39 (133) ◽  
pp. 656-665 ◽  
Author(s):  
Tron Laumann ◽  
Niels Reeh
Keyword(s):  
Mass Balance ◽  
Atlantic Coast ◽  
Elevation Gradient ◽  
Greenland Ice Sheet ◽  
Climatic Conditions ◽  
Model Parameters ◽  
Average Mass ◽  
Degree Day ◽  
Temperature And Precipitation ◽  
Southern Norway

Abstract A degree-day model developed for parameterizing melt rates on the Greenland ice sheet is adapted to the climatic conditions on glaciers in southern Norway. The model is calibrated by means of observed average mass-balance-elevation relationships (1963–90) for three glaciers in a west-east transect in southern Norway and 30 year normals (1961–90) of temperature and precipitation observed at nearby climate stations. The calibration gives a surprisingly small variation of the model parameters (degree-day factors for snow-and ice-melt, and precipitation-elevation gradient) from one glacier to another. The derived values of the parameters are used to estimate the change of the mass-balance-elevation relationship for different climatic scenarios. The study indicates that a low-lying glacier in the maritime, high-precipitation environment near the Atlantic coast is more sensitive to both temperature and precipitation changes than the high elevated glaciers in the dry, more continental climate farther away from the coast. However, all of the glaciers studied will lose mass in a warmer climate, unless the warming is accompanied by a dramatic increase in the precipitation of 25–40% deg−1 warming.

scholarly journals Topographic influences on recent changes of very small glaciers in the Monashee Mountains, British Columbia, Canada

2009 ◽  
Vol 55 (192) ◽  
pp. 691-700 ◽  
Author(s):  
Christopher M. DeBeer ◽  
Martin J. Sharp
Keyword(s):  
British Columbia ◽  
Mass Balance ◽  
20Th Century ◽  
Small Region ◽  
Remotely Sensed ◽  
Climatic Conditions ◽  
Late 20Th Century ◽  
Local Mass ◽  
Remotely Sensed Imagery

AbstractAn analysis of the local topographic setting of very small (<0.4 km2) glaciers within a small region of the Monashee Mountains, British Columbia, was conducted to investigate its influence on recent changes in the extent of these glaciers. Net changes in glacier extent were determined from a detailed manual comparison of remotely sensed imagery acquired in 1951, 2001 and 2004. Most of the 86 glaciers included in the study showed no observable net change in area over the study period, while six glaciers retreated, four disappeared entirely and only one advanced. Indices derived to characterize elements of the local topographic setting that might affect the local mass balance suggest that most of the glaciers are situated in locations that favor ice preservation by enhancing mass input and/or reducing ablation rates. Glaciers situated in less favorable settings generally either decreased in area or disappeared. The results suggest that most of the glaciers studied have retreated as far as they are likely to under the climatic conditions of the late 20th century.

scholarly journals Long-Term Glacier Mass-Balance Investigations in Svalbard, 1950–88

1990 ◽  
Vol 14 ◽  
pp. 102-106 ◽  
Author(s):  
Jon Ove Hagen ◽  
Olav Liestøl
Keyword(s):  
Mass Balance ◽  
Winter Precipitation ◽  
Summer Temperature ◽  
Glacier Mass Balance ◽  
Climatic Warming ◽  
Equilibrium Line Altitude ◽  
Stable Conditions ◽  
The Mean ◽  
One Year

Mass-balance investigations on glaciers in Svalbard at high latitudes (78°N) show that the ice masses have been steadily decreasing during the period 1950–88. Detailed annual observations have been carried out on Brøggerbreen since 1966 and Lovénbreen since 1967. The mean specific net balances are −0.46 and −0.37 m year−1 water equivalent respectively. Only one year had positive net balance in this period. The cumulative mass lost in the period is then more than 10% of the volume in 1967. Zero net balance would be obtained if the summer temperature was lowered about 1°C or if the winter precipitation increased about 50%. There is a strong correlation between the net mass balance and the height of the equilibrium-line altitude (ELA). Because of the high amount of superimposed ice (10–30% of winter balance) stake readings are necessary to find the ELA. There is no sign of climatic warming through increased melting. The trend analysis of the data from the last 20 years shows stable conditions with a slight increase of the winter balance. The net balance is then slightly increasing and thus less negative than 20 years ago.

scholarly journals The Use of Hypsometry to Indicate Long-Term Stability and Response of Valley Glaciers to Changes in Mass Transfer

1984 ◽  
Vol 30 (105) ◽  
pp. 199-211 ◽  
Author(s):  
D.J Furbish ◽  
J.T. Andrews
Keyword(s):  
Mass Balance ◽  
Climatic Conditions ◽  
Topographic Maps ◽  
Equilibrium Line Altitude ◽  
Climatic Influence ◽  
Long Term Stability ◽  
Valley Glacier ◽  
Similar Information ◽  
Dimensionless Ratio

AbstractA simple equation is derived relating the net mass-balance and hypsometric curves of a steady-state valley glacier. It is used to examine how valley shape is linked to disparate extents and responses of glaciers subjected to similar climatic conditions. Examples are given which show that area-based indices (e.g. AAR) for estimating the equilibrium line altitude (ELA) may be subject to a substantial built-in variance because they implicitly rely upon similarity of glacier shape and regimen over a region. If accurate topographic maps are available, the equation may be used to infer the regimen of modern glaciers in the form of a dimensionless ratio of net mass-balance gradients. Alternatively, if similar information is available concerning regional glacier regimen, disparate extents and responses may be collectively utilized to estimate values of ELA or to infer climatic influence, taking glacier hypsometry into account.

scholarly journals Methods of Calculation and Remote-Sensing Measurements for the Spatial Distribution of Glacier Annual Mass Balances (Abstract)

1987 ◽  
Vol 9 ◽  
pp. 248-248
Author(s):  
V.G. Konovalov
Keyword(s):  
Remote Sensing ◽  
Spatial Distribution ◽  
Mass Balance ◽  
Single Point ◽  
Mountain Glaciers ◽  
A Value ◽  
Air Temperatures ◽  
Using Data ◽  
Absolute Altitude

The areal distribution of glacier annual mass balance b(z) is an important characteristic of the existence of glacierization and its evolution. At present the measured value of annual mass balance at different elevations is only available for a limited number of mountain glaciers of the globe, because of the great amount of labour required for such measurements.The analysis of long-term mass-balance measurements made at Abramova Glacier, Limmerngletscher, White Glacier, Hintereisferner, and Peyto Glacier has revealed that for each year the spatial distribution of annual mass balance is well described by quadratic equations. The main variable in these equations is altitude (z). The various parameters of these formulae are estimated by the author for mean weighted height of the ablation and accumulation areas, and for the glaciers as a whole. It is found that the parameters of annual mass balance for each glacier can be calculated from formulae which include combinations of the following variables: annual balance at one of the three weighted altitudes, maximum annual snow-line elevation, annual and seasonal amounts of precipitation, and air temperatures at nearby meteorological stations.Therefore, in order to calculate the distribution of annual mass balance as a function of absolute altitude, it is sufficient to obtain a value for mass balance measured only at a single point on a glacier, and common meteorological observational data. A comparison of actual and calculated values of mass balance has shown good agreement between them.Considering the successful use of aerial remote-sensing for the measurement of snow depth in mountains by means of special stakes, it is satisfactory to accept this method for the assessment of annual mass balance at the mean weighted altitude of the ablation zone. It is possible to use aerial photo-surveys or stereophotogrammetry to resolve this problem. Then annual mass balance for the whole area of a glacier is calculated by using data from one point together with data from a nearby meteorological station.

scholarly journals Sensitivity to climate change of the mass balance of glaciers in southern Norway

1993 ◽  
Vol 39 (133) ◽  
pp. 656-665 ◽  
Author(s):  
Tron Laumann ◽  
Niels Reeh
Keyword(s):  
Mass Balance ◽  
Atlantic Coast ◽  
Elevation Gradient ◽  
Greenland Ice Sheet ◽  
Climatic Conditions ◽  
Model Parameters ◽  
Average Mass ◽  
Degree Day ◽  
Temperature And Precipitation ◽  
Southern Norway

AbstractA degree-day model developed for parameterizing melt rates on the Greenland ice sheet is adapted to the climatic conditions on glaciers in southern Norway. The model is calibrated by means of observed average mass-balance-elevation relationships (1963–90) for three glaciers in a west-east transect in southern Norway and 30 year normals (1961–90) of temperature and precipitation observed at nearby climate stations. The calibration gives a surprisingly small variation of the model parameters (degree-day factors for snow-and ice-melt, and precipitation-elevation gradient) from one glacier to another. The derived values of the parameters are used to estimate the change of the mass-balance-elevation relationship for different climatic scenarios. The study indicates that a low-lying glacier in the maritime, high-precipitation environment near the Atlantic coast is more sensitive to both temperature and precipitation changes than the high elevated glaciers in the dry, more continental climate farther away from the coast. However, all of the glaciers studied will lose mass in a warmer climate, unless the warming is accompanied by a dramatic increase in the precipitation of 25–40% deg−1 warming.

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