scholarly journals Temperature and Melt Modeling on the Prince of Wales Ice Field, Canadian High Arctic

2009 ◽  
Vol 22 (6) ◽  
pp. 1454-1468 ◽  
Author(s):  
Shawn J. Marshall ◽  
Martin J. Sharp
Keyword(s):  
Surface Temperature ◽  
Mass Balance ◽  
High Arctic ◽  
Temperature Variability ◽  
Lapse Rate ◽  
Glacier Mass Balance ◽  
Seasonal Temperature ◽  
Near Surface ◽  
Ice Melt ◽  
Ice Field

Abstract Near-surface temperature variability and net annual mass balance were monitored from May 2001 to April 2003 in a network of 25 sites on the Prince of Wales Ice Field, Ellesmere Island, Canada. The observational array spanned an area of 180 km by 120 km and ranged from 130 to 2010 m in altitude. Hourly, daily, and monthly average temperatures from the spatial array provide a record of mesoscale temperature variability on the ice field. The authors examine seasonal variations in the variance of monthly and daily temperature: free parameters in positive-degree-day melt models that are presently in use for modeling of glacier mass balance. An analysis of parameter space reveals that daily and seasonal temperature variability are suppressed in summer months (over a melting snow–ice surface), an effect that is important to include in melt modeling. In addition, average annual vertical gradients in near-surface temperature were −3.7°C km−1 in the 2-yr record, steepening to −4.4°C km−1 in the summer months. These gradients are less than the adiabatic lapse rates that are commonly adopted for extrapolation of sea level temperature to higher altitudes, with significant implications for modeling of snow and ice melt. Mass balance simulations for the ice field illustrate the sensitivity of melt models to different lapse rate and temperature parameterizations.

scholarly journals Derivation of melt factors from glacier mass-balance records in western Canada

2009 ◽  
Vol 55 (189) ◽  
pp. 123-130 ◽  
Author(s):  
Joseph M. Shea ◽  
R. Dan Moore ◽  
Kerstin Stahl
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Regional Scale ◽  
Predictive Ability ◽  
Lapse Rate ◽  
Sensitivity Analyses ◽  
Glacier Mass Balance ◽  
Mean Values ◽  
Ice Melt ◽  
Standard Deviations

AbstractMelt factors for snow (ks) and ice (ki) were derived from specific mass-balance data and regionally interpolated daily air-temperature series at nine glaciers in the western Cordillera of Canada. Fitted ks and ki were relatively consistent across the region, with mean values (standard deviations) of 3.04 (0.38) and 4.59 (0.59) mm d−1 °C−1, respectively. The interannual variability of melt factors was investigated for two long-term datasets. Calculated annually, snow- and ice-melt factors were relatively stable from year to year; standard deviations for snowmelt factors were 0.48 (17%) and 0.42 (18%) at Peyto and Place Glaciers, respectively, while standard deviations of ice-melt factors were 1.17 (25%) and 0.81 (14%). While fitted values of ks are comparable to those presented in previous observational and modeling studies, fitted ki are substantially and consistently lower across the region. Fitted melt factors were sensitive to the choice of lapse rate used in the air-temperature interpolation. Melt factors fitted to mass-balance data from a single site (Place Glacier) provided reasonable summer balance predictions at most other sites representing both maritime and continental climates, although there was a tendency for under-prediction at several sites. The combination of regionally interpolated air temperatures and a degree-day model appears capable of generating first-order estimates of regional summer balance, which can provide a benchmark against which to judge the predictive ability of more complex (e.g. energy balance) models applied at a regional scale. Mass-balance sensitivity analyses indicate that a temperature increase of 1 K will increase summer ablation in the region by 0.51 m w.e. a−1 on average.

scholarly journals The influence of superimposed-ice formation on the sensitivity of glacier mass balance to climate change

1997 ◽  
Vol 24 ◽  
pp. 186-190 ◽  
Author(s):  
John Woodward ◽  
Martin Sharp ◽  
Anthony Arendt
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
High Arctic ◽  
Snow Accumulation ◽  
Ice Formation ◽  
Mean Annual Temperature ◽  
Glacier Mass Balance ◽  
Specific Mass ◽  
Near Surface ◽  
Mean Annual Air Temperature

The formation of superimposed ice at the surface of high-Arctic glaciers is an important control on glacier mass balance, but one which is usually modelled in only a schematic fashion. A method is developed to predict the relationship between the thickness of superimposed ice formed and the mean annual air temperature (which approximates the ice temperature at 14 m depth). This relationship is used to investigate the dependence of the proportion of snowpack water equivalent which forms superimposed ice on changes in mean annual temperature and patterns of snow accumulation. Increased temperatures are likely to reduce the extent of the zone of superimposed-ice accumulation and the thickness of superimposed ice formed. This will have a negative effect on glacier mass balance. This is true even if warming occurs only in the winter months, since near-surface ice temperatures will respond to such warming. For John Evans Glacier, Ellesmere Island, Nunavut, Canada (79°40’ N, 74°00’ W), a 1°C rise in mean annual air temperature due solely to winter warming is predicted to reduce the specific mass balance of the glacier by 0.008 m a–1 as a result of decreased superimposed-ice formation. Although such a response is small in comparison to the changes which might result from summer warming, it is nonetheless significant given the very low specific mass balance of many high-Arctic glaciers.

scholarly journals The influence of superimposed-ice formation on the sensitivity of glacier mass balance to climate change

1997 ◽  
Vol 24 ◽  
pp. 186-190 ◽  
Author(s):  
John Woodward ◽  
Martin Sharp ◽  
Anthony Arendt
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
High Arctic ◽  
Snow Accumulation ◽  
Ice Formation ◽  
Mean Annual Temperature ◽  
Glacier Mass Balance ◽  
Specific Mass ◽  
Near Surface ◽  
Mean Annual Air Temperature

The formation of superimposed ice at the surface of high-Arctic glaciers is an important control on glacier mass balance, but one which is usually modelled in only a schematic fashion. A method is developed to predict the relationship between the thickness of superimposed ice formed and the mean annual air temperature (which approximates the ice temperature at 14 m depth). This relationship is used to investigate the dependence of the proportion of snowpack water equivalent which forms superimposed ice on changes in mean annual temperature and patterns of snow accumulation.Increased temperatures are likely to reduce the extent of the zone of superimposed-ice accumulation and the thickness of superimposed ice formed. This will have a negative effect on glacier mass balance. This is true even if warming occurs only in the winter months, since near-surface ice temperatures will respond to such warming. For John Evans Glacier, Ellesmere Island, Nunavut, Canada (79°40’ N, 74°00’ W), a 1°C rise in mean annual air temperature due solely to winter warming is predicted to reduce the specific mass balance of the glacier by 0.008 m a–1 as a result of decreased superimposed-ice formation. Although such a response is small in comparison to the changes which might result from summer warming, it is nonetheless significant given the very low specific mass balance of many high-Arctic glaciers.

scholarly journals Glacier runoff variations since 1955 in the Maipo River basin, in the semiarid Andes of central Chile

2020 ◽  
Vol 14 (6) ◽  
pp. 2005-2027 ◽  
Author(s):  
Álvaro Ayala ◽  
David Farías-Barahona ◽  
Matthias Huss ◽  
Francesca Pellicciotti ◽  
James McPhee ◽  
...  
Keyword(s):  
Mass Balance ◽  
River Basin ◽  
Climate Scenario ◽  
Glacier Mass Balance ◽  
Time Step ◽  
Ice Melt ◽  
Kinematic Approximation ◽  
Glacier Runoff ◽  
Drought Mitigation ◽  
Year 2000

Abstract. As glaciers adjust their size in response to climate variations, long-term changes in meltwater production can be expected, affecting the local availability of water resources. We investigate glacier runoff in the period 1955–2016 in the Maipo River basin (4843 km2, 33.0–34.3∘ S, 69.8–70.5∘ W), in the semiarid Andes of Chile. The basin contains more than 800 glaciers, which cover 378 km2 in total (inventoried in 2000). We model the mass balance and runoff contribution of 26 glaciers with the physically oriented and fully distributed TOPKAPI (Topographic Kinematic Approximation and Integration)-ETH glacio-hydrological model and extrapolate the results to the entire basin. TOPKAPI-ETH is run at a daily time step using several glaciological and meteorological datasets, and its results are evaluated against streamflow records, remotely sensed snow cover, and geodetic mass balances for the periods 1955–2000 and 2000–2013. Results show that in 1955–2016 glacier mass balance had a general decreasing trend as a basin average but also had differences between the main sub-catchments. Glacier volume decreased by one-fifth (from 18.6±4.5 to 14.9±2.9 km3). Runoff from the initially glacierized areas was 177±25 mm yr−1 (16±7 % of the total contributions to the basin), but it shows a decreasing sequence of maxima, which can be linked to the interplay between a decrease in precipitation since the 1980s and the reduction of ice melt. Glaciers in the Maipo River basin will continue retreating because they are not in equilibrium with the current climate. In a hypothetical constant climate scenario, glacier volume would reduce to 81±38 % of the year 2000 volume, and glacier runoff would be 78±30 % of the 1955–2016 average. This would considerably decrease the drought mitigation capacity of the basin.

A new approach for modeling near surface temperature lapse rate based on normalized land surface temperature data

2020 ◽  
Vol 242 ◽  
pp. 111746 ◽  
Author(s):  
Mohammad Karimi Firozjaei ◽  
Solmaz Fathololoumi ◽  
Seyed Kazem Alavipanah ◽  
Majid Kiavarz ◽  
Ali Reza Vaezi ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Temperature Data ◽  
Lapse Rate ◽  
Near Surface ◽  
New Approach ◽  
Temperature Lapse Rate ◽  
Surface Temperature Data

scholarly journals Morphometric Controls on Glacier Mass Balance of the Puruogangri Ice Field, Central Tibetan Plateau

Water ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 496 ◽  
Author(s):  
Lin Liu ◽  
Liming Jiang ◽  
Yafei Sun ◽  
Hansheng Wang ◽  
Chaolu Yi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Glacier Mass Balance ◽  
Central Tibetan Plateau ◽  
Ice Field

scholarly journals An Evaluation of Surface Climatology in State-of-the-Art Reanalyses over the Antarctic Ice Sheet

2019 ◽  
Vol 32 (20) ◽  
pp. 6899-6915 ◽  
Author(s):  
A. Gossart ◽  
S. Helsen ◽  
J. T. M. Lenaerts ◽  
S. Vanden Broucke ◽  
N. P. M. van Lipzig ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Surface Temperature ◽  
Mass Balance ◽  
Ice Sheet ◽  
Surface Mass Balance ◽  
Antarctic Ice Sheet ◽  
Near Surface ◽  
Surface Mass ◽  
Atmospheric Rivers ◽  
The Antarctic

Abstract In this study, we evaluate output of near-surface atmospheric variables over the Antarctic Ice Sheet from four reanalyses: the new European Centre for Medium-Range Weather Forecasts ERA-5 and its predecessor ERA-Interim, the Climate Forecast System Reanalysis (CFSR), and the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The near-surface temperature, wind speed, and relative humidity are compared with datasets of in situ observations, together with an assessment of the simulated surface mass balance (approximated by precipitation minus evaporation). No reanalysis clearly stands out as the best performing for all areas, seasons, and variables, and each of the reanalyses displays different biases. CFSR strongly overestimates the relative humidity during all seasons whereas ERA-5 and MERRA-2 (and, to a lesser extent, ERA-Interim) strongly underestimate relative humidity during winter. ERA-5 captures the seasonal cycle of near-surface temperature best and shows the smallest bias relative to the observations. The other reanalyses show a general temperature underestimation during the winter months in the Antarctic interior and overestimation in the coastal areas. All reanalyses underestimate the mean near-surface winds in the interior (except MERRA-2) and along the coast during the entire year. The winds at the Antarctic Peninsula are overestimated by all reanalyses except MERRA-2. All models are able to capture snowfall patterns related to atmospheric rivers, with varying accuracy. Accumulation is best represented by ERA-5, although it underestimates observed surface mass balance and there is some variability in the accumulation over the different elevation classes, for all reanalyses.

scholarly journals Multi-decadal mass loss of glaciers in the Everest area (Nepal Himalaya) derived from stereo imagery

2011 ◽  
Vol 5 (2) ◽  
pp. 349-358 ◽  
Author(s):  
T. Bolch ◽  
T. Pieczonka ◽  
D. I. Benn
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Mass Balance ◽  
Aerial Images ◽  
Glacier Mass Balance ◽  
Ice Melt ◽  
Debris Cover ◽  
Stereo Imagery ◽  
Glacier Velocity ◽  
The Himalaya

Abstract. Mass loss of Himalayan glaciers has wide-ranging consequences such as changing runoff distribution, sea level rise and an increasing risk of glacial lake outburst floods (GLOFs). The assessment of the regional and global impact of glacier changes in the Himalaya is, however, hampered by a lack of mass balance data for most of the range. Multi-temporal digital terrain models (DTMs) allow glacier mass balance to be calculated. Here, we present a time series of mass changes for ten glaciers covering an area of about 50 km2 south and west of Mt. Everest, Nepal, using stereo Corona spy imagery (years 1962 and 1970), aerial images and recent high resolution satellite data (Cartosat-1). This is the longest time series of mass changes in the Himalaya. We reveal that the glaciers have been significantly losing mass since at least 1970, despite thick debris cover. The specific mass loss for 1970–2007 is 0.32 ± 0.08 m w.e. a−1, however, not higher than the global average. Comparisons of the recent DTMs with earlier time periods indicate an accelerated mass loss. This is, however, hardly statistically significant due to high uncertainty, especially of the lower resolution ASTER DTM. The characteristics of surface lowering can be explained by spatial variations of glacier velocity, the thickness of the debris-cover, and ice melt due to exposed ice cliffs and ponds.

scholarly journals Influence of the Arctic Circumpolar Vortex on the Mass Balance of Canadian High Arctic Glaciers

2007 ◽  
Vol 20 (18) ◽  
pp. 4586-4598 ◽  
Author(s):  
Alex S. Gardner ◽  
Martin Sharp
Keyword(s):  
Mass Balance ◽  
Regime Shift ◽  
High Arctic ◽  
Western Hemisphere ◽  
The Arctic ◽  
Glacier Mass Balance ◽  
Canadian High Arctic ◽  
Circumpolar Vortex ◽  
Eastern Hemisphere ◽  
Air Temperatures

Abstract Variability in July mean surface air temperatures from 1963 to 2003 accounted for 62% of the variance in the regional annual glacier mass balance signal for the Canadian High Arctic. A regime shift to more negative regional glacier mass balance occurred between 1986 and 1987, and is linked to a coincident shift from lower to higher mean July air temperatures. Both the interannual changes and the regime shifts in regional glacier mass balance and July air temperatures are related to variations in the position and strength of the July circumpolar vortex. In years when the July vortex is “strong” and its center is located in the Western Hemisphere, positive mass balance anomalies prevail. In contrast, highly negative mass balance anomalies occur when the July circumpolar vortex is either weak or strong without elongation over the Canadian High Arctic, and its center is located in the Eastern Hemisphere. The occurrence of westerly positioned July vortices has decreased by 40% since 1987. The associated shift to a dominantly easterly positioned July vortex was associated with an increased frequency of tropospheric ridging over the Canadian High Arctic, higher surface air temperatures, and more negative regional glacier mass balance.

scholarly journals Preliminary results of mass-balance observations of Yala Glacier and analysis of temperature and precipitation gradients in Langtang Valley, Nepal

2014 ◽  
Vol 55 (66) ◽  
pp. 9-14 ◽  
Author(s):  
Prashant Baral ◽  
Rijan B. Kayastha ◽  
Walter W. Immerzeel ◽  
Niraj S. Pradhananga ◽  
Bikas C. Bhattarai ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Lapse Rate ◽  
Convective Precipitation ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Temperature And Precipitation ◽  
Meteorological Observations ◽  
The Impact ◽  
Langtang Valley

AbstractMonitoring the glacier mass balance of summer-accumulation-type Himalayan glaciers is critical to not only assess the impact of climate change on the volume of such glaciers but also predict the downstream water availability and the global sea-level change in future. To better understand the change in meteorological parameters related to glacier mass balance and runoff in a glacierized basin and to assess the highly heterogeneous glacier responses to climate change in the Nepal Himalaya and nearby ranges, the Cryosphere Monitoring Project (CMP) carries out meteorological observations in Langtang Valley and mass-balance measurements on Yala Glacier, a debris-free glacier in the same valley. A negative annual mass balance of –0.89m w.e. and the rising equilibrium-line altitude of Yala Glacier indicate a continuation of a secular trend toward more negative mass balances. Lower temperature lapse rate during the monsoon, the effect of convective precipitation associated with mesoscale thermal circulation in the local precipitation and the occurrence of distinct diurnal cycles of temperature and precipitation at different stations in the valley are other conclusions of this comprehensive scientific study initiated by CMP which aims to yield multi-year glaciological, hydrological and meteorological observations in the glacierized Langtang River basin.

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