scholarly journals Snow Distribution and Melt Modeling for Mittivakkat Glacier, Ammassalik Island, Southeast Greenland

2006 ◽  
Vol 7 (4) ◽  
pp. 808-824 ◽  
Author(s):  
Sebastian H. Mernild ◽  
Glen E. Liston ◽  
Bent Hasholt ◽  
Niels T. Knudsen
Keyword(s):  
Mass Balance ◽  
Snow Water Equivalent ◽  
Snow Accumulation ◽  
Equilibrium Line Altitude ◽  
Ice Melt ◽  
Solid Precipitation ◽  
Glacier Terminus ◽  
Winter Snow ◽  
Glacier Ice ◽  
Surface Melt

Abstract A physically based snow-evolution modeling system (SnowModel) that includes four submodels—the Micrometeorological Model (MicroMet), EnBal, SnowPack, and SnowTran-3D—was used to simulate five full-year evolutions of snow accumulation, distribution, sublimation, and surface melt on the Mittivakkat Glacier, in southeast Greenland. Model modifications were implemented and used 1) to adjust underestimated observed meteorological station solid precipitation until the model matched the observed Mittivakkat Glacier winter mass balance, and 2) to simulate glacier-ice melt after the winter snow accumulation had ablated. Meteorological observations from two meteorological stations were used as model inputs, and glaciological mass balance observations were used for model calibration and testing of solid precipitation observations. The modeled end-of-winter snow-water equivalent (w.eq.) accumulation increased with elevation from 200 to 700 m above sea level (ASL) in response to both elevation and topographic influences, and the simulated end-of-summer location of the glacier equilibrium line altitude was confirmed by glaciological observations and digital images. The modeled test-period-averaged annual mass balance was 150 mm w.eq. yr−1, or ∼15%, less than the observed. Approximately 12% of the precipitation was returned to the atmosphere by sublimation. Glacier-averaged mean annual modeled surface melt ranged from 1272 to 2221 mm w.eq. yr−1, of which snowmelt contributed from 610 to 1040 mm w.eq. yr−1. The surface-melt period started between mid-May and the beginning of June, and lasted until mid-September; there were as many as 120 melt days at the glacier terminus. The model simulated a Mittivakkat Glacier recession averaging −616 mm w.eq. yr−1, almost equal to the observed −600 mm w.eq. yr−1.

scholarly journals The Influence of Air Temperature Inversions on Snowmelt and Glacier Mass Balance Simulations, Ammassalik Island, Southeast Greenland

2010 ◽  
Vol 49 (1) ◽  
pp. 47-67 ◽  
Author(s):  
Sebastian H. Mernild ◽  
Glen E. Liston
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Inversion Layer ◽  
Snow Accumulation ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Surface Mass ◽  
Simulation Domain ◽  
Glacier Ice ◽  
Temperature Inversions

Abstract In many applications, a realistic description of air temperature inversions is essential for accurate snow and glacier ice melt, and glacier mass-balance simulations. A physically based snow evolution modeling system (SnowModel) was used to simulate 8 yr (1998/99–2005/06) of snow accumulation and snow and glacier ice ablation from numerous small coastal marginal glaciers on the SW part of Ammassalik Island in SE Greenland. These glaciers are regularly influenced by inversions and sea breezes associated with the adjacent relatively low temperature and frequently ice-choked fjords and ocean. To account for the influence of these inversions on the spatiotemporal variation of air temperature and snow and glacier melt rates, temperature inversion routines were added to MircoMet, the meteorological distribution submodel used in SnowModel. The inversions were observed and modeled to occur during 84% of the simulation period. Modeled inversions were defined not to occur during days with strong winds and high precipitation rates because of the potential of inversion breakup. Field observations showed inversions to extend from sea level to approximately 300 m MSL, and this inversion level was prescribed in the model simulations. Simulations with and without the inversion routines were compared. The inversion model produced air temperature distributions with warmer lower-elevation areas and cooler higher-elevation areas than without inversion routines because of the use of cold sea-breeze-based temperature data from underneath the inversion. This yielded an up to 2 weeks earlier snowmelt in the lower areas and up to 1–3 weeks later snowmelt in the higher-elevation areas of the simulation domain. Averaged mean annual modeled surface mass balance for all glaciers (mainly located above the inversion layer) was −720 ± 620 mm w.eq. yr−1 (w.eq. is water equivalent) for inversion simulations, and −880 ± 620 mm w.eq. yr−1 without the inversion routines, a difference of 160 mm w.eq. yr−1. The annual glacier loss for the two simulations was 50.7 × 106 and 64.4 × 106 m3 yr−1 for all glaciers—a difference of ∼21%. The average equilibrium line altitude (ELA) for all glaciers in the simulation domain was located at 875 and 900 m MSL for simulations with or without inversion routines, respectively.

scholarly journals Surface Melt Area and Water Balance Modeling on the Greenland Ice Sheet 1995–2005

2008 ◽  
Vol 9 (6) ◽  
pp. 1191-1211 ◽  
Author(s):  
Sebastian H. Mernild ◽  
Glen E. Liston ◽  
Christopher A. Hiemstra ◽  
Konrad Steffen
Keyword(s):  
Water Balance ◽  
Mass Balance ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Time Lapse ◽  
Water Balance Components ◽  
Equilibrium Line Altitude ◽  
Surface Mass ◽  
Ice Melt ◽  
Surface Melt

Abstract SnowModel, a physically based snow-evolution modeling system that includes four submodels—MicroMet, EnBal, SnowPack, and SnowTran-3D—was used to simulate variations in Greenland [including the Greenland Ice Sheet (GrIS)] surface snow and ice melt, as well as water balance components, for 1995–2005. Meteorological observations from 25 stations inside and outside the GrIS were used as model input. Winter and summer mass balance observations, spatial snow depth observations, and snowmelt depletion curves derived from time-lapse photography from the Mittivakkat and Zackenberg glacierized catchments in East Greenland were used to validate the performance of SnowModel. Model results compared well with observed values, confirming the robustness of the model. The yearly modeled GrIS interior nonmelt area differs from satellite observations by a maximum of ∼68 000 km2 (or ∼6%) in 2004, and the lowest uncertainties (<8000 km2, or <1%) occur for the years with the smallest (2005) and most extensive (1996) nonmelt areas. Modeled surface melt occurred at elevations reaching 2950 m MSL for 2005, while the equilibrium line altitude (ELA) fluctuates from 1640 to 600 m MSL. The modeled interannual variability in the nonmelt area also agrees with observation records (R2 = 0.96), yielding simulated GrIS nonmelt covers of 71% for 1996 and 50% for 2005. On average, the simulated nonmelt area decreased ∼6% from 1995 to 2005; this trend is similar to observed values. An average surface mass balance (SMB) storage of 138(±81) km3 yr−1, a GrIS loss of 257(±81) km3 yr−1, and a runoff contribution to the ocean of 392(±58) km3 yr−1 occurred for the period 1995–2005. Approximately 58% and 42% of the runoff came from the GrIS western and eastern drainage areas, respectively. The modeled average specific runoff from the GrIS was 6.71 s−1 km−2 yr−1, which, over the simulation period, represents a contribution of ∼1.1 mm yr−1 to global sea level rise.

Can the mass balance of the entire glacier area of the Tien Shan be estimated?

1992 ◽  
Vol 16 ◽  
pp. 173-179
Author(s):  
M.B. Dyurgerov ◽  
M.G. Kunakhovitch ◽  
V.N. Mikhalenko ◽  
A. M. Sokalskaya ◽  
V. A. Kuzmichenok
Keyword(s):  
Mass Balance ◽  
Vertical Profile ◽  
River Basins ◽  
Annual Runoff ◽  
Snow Accumulation ◽  
Tien Shan ◽  
Exponential Dependence ◽  
Glacier Area ◽  
Equilibrium Line Altitude ◽  
Boundary Area

The total area of glacierization of the Tien Shan in the boundary area of the USSR is about 8000 km2. The computation of mass balance was determined for this area in 12 river basins.In computation procedure, the vertical profile of snow accumulation in these regions and exponential dependence of variation of ablation with altitude are used. Thus the mass balance in each basin, bn, was calculated on the basis of these curves and represented in its relation with the equilibrium line altitude (ELA). It is shown that the relation ELA = f(bn) is linear when the range of bn values is close to zero, and in all altitude intervals this relation can be described by hypsographic curves, in all basins bn positive up to an ELA elevation of 3450 to 3500 m a.s.l. For average annual altitude of ELA, bn is negative for all regions. So the glaciers of these mountains add about 4 km3 of water to the total annual runoff.

scholarly journals The Northeast Asia mountain glaciers in the near future by AOGCM scenarios

2010 ◽  
Vol 4 (4) ◽  
pp. 435-445 ◽  
Author(s):  
M. D. Ananicheva ◽  
A. N. Krenke ◽  
R. G. Barry
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Northeast Asia ◽  
Morphological Structure ◽  
Kamchatka Peninsula ◽  
Baseline Period ◽  
Equilibrium Line Altitude ◽  
Mountain Glaciers ◽  
Glacier System ◽  
Glacier Terminus

Abstract. We studied contrasting glacier systems in continental (Orulgan, Suntar-Khayata and Chersky) mountain ranges, located in the region of the lowest temperatures in the Northern Hemisphere at the boundary of Atlantic and Pacific influences – and maritime ones (Kamchatka Peninsula) – under Pacific influence. Our purpose is to present a simple projection method to assess the main parameters of these glacier regions under climate change. To achieve this, constructed vertical profiles of mass balance (accumulation and ablation) based both on meteorological data for the 1950–1990s (baseline period) and ECHAM4 for 2049–2060 (projected period) are used, the latter – as a climatic scenario. The observations and scenarios were used to define the recent and future equilibrium line altitude and glacier terminus altitude level for each glacier system as well as areas and balance components. The altitudinal distributions of ice areas were determined for present and future, and they were used for prediction of glacier extent versus altitude in the system taking into account the correlation between the ELA and glacier-terminus level change. We tested two hypotheses of ice distribution versus altitude in mountain (valley) glaciers – "linear" and "non-linear". The results are estimates of the possible changes of the areas and morphological structure of northeastern Asia glacier systems and their mass balance characteristics for 2049–2060. Glaciers in the southern parts of northeastern Siberia and those covering small ranges in Kamchatka will likely disappear under the ECHAM4 scenario; the best preservation of glaciers will be on the highest volcanic peaks of Kamchatka. Finally, we compare characteristics of the stability of continental and maritime glacier systems under global warming.

scholarly journals Field Study of Mass Balance, and Hydrology of the West Khangri Nup Glacier (Khumbu, Everest)

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 433
Author(s):  
Daniele Bocchiola ◽  
Giovanni Martino Bombelli ◽  
Federica Camin ◽  
Paolo Maria Ossi
Keyword(s):  
Mass Balance ◽  
Original Data ◽  
Snow Accumulation ◽  
High Altitudes ◽  
Landsat Images ◽  
Ice Melt ◽  
Seasonal Snow ◽  
Hydrological Fluxes ◽  
Set Up ◽  
Ice Water

The depiction of glaciers’ dynamics in the high altitudes of Himalaya and the hydrological fluxes therein is often limited. Although sparse seasonal (snow/ice) melt data may be available, dense precipitation networks are not available everywhere, and especially in the highest area, and the assessment of accumulation processes and mass balance may be difficult. Hydrological fluxes are little measured in the high altitudes, and few studies are available covering flow modeling and flow partitioning. Here, we investigate the snow accumulation, ice melt, and mass balance of West Khangri Nup (WKN) glacier (0.23 km2, mean altitude 5494 m asl), which is a part of the Khumbu glacier in the Everest region, where information of precipitation and hydro-glaciological dynamics in the highest altitudes was made available recently in fulfillment of several research projects. Weather, glaciological, snow pits, hydrologic, and isotopic data gathered during field campaigns (2010–2014) on the glacier and at the EVK2CNR Pyramid site were used to (i) set up the Poli-Hydro glacio-hydrological model to describe ice and snow melt and hydrological flows from the glacier, and (ii) investigate seasonal snow dynamics on this high region of the glacier. Coupling ice ablation data and Poli-Hydro simulation for ca. 5 years (January 2010–June 2014), we estimate that the WKN depleted ca. −10.46 m of ice water equivalent per year m IWE year−1 (i.e., annually ca. −2.32 meter of water equivalent per year m WE year−1). Then, using snowpack density and isotopic (δ18O) profiles on the WKN, we demonstrate that the local snowpack is recent (Fall–Winter 2013–2014) and that significant snow accumulation did not occur recently, so this area has not been a significant one of accumulation recently. Analysis of recent snow cover from LANDSAT images also confirms snow dynamics as depicted. Our study presents original data and results, and it complements present studies covering glaciers’ mass balance as well as an investigation of accumulation zones in the Everest region and the Himalayas, which is also potentially helpful in the assessment of future dynamics under ongoing climate change.

scholarly journals Simulating the effects of mean annual air-temperature changes on permafrost distribution and glacier size: an example from the Upper Engadin, Swiss Alps

1995 ◽  
Vol 21 ◽  
pp. 399-405 ◽  
Author(s):  
Martin Hoelzle ◽  
Wilfried Haeberli
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Swiss Alps ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Mountain Areas ◽  
Model Calculations ◽  
Glacier Terminus ◽  
Time Period ◽  
Mean Annual Air Temperature

Models are developed to simulate changes in permafrost distribution and glacier size in mountain areas. The models exclusively consider equilibrium conditions. As a first application, the simplified assumption is used that one single parameter (mean annual air temperature) is changing. Permafrost distribution patterns are estimated for a test area (Corvatsch-Furtschellas) and for the whole Upper Engadin region (eastern Swiss Alps) using a relation between permafrost occurrence as indicated by BTS (bottom temperature of the winter snow cover) measurements, potential direct solar radiation and mean annual air temperature. Glacier sizes were assessed in the same region with data from the World Glacier Inventory database. The simulations for the glaciers are based on the assumption that an increase or decrease in equilibrium-line altitude (ELA) would lead to a mass-balance change. Model calculations for potential future changes in ELA and mass balance include estimated developments of area, length and volume. Mass changes were also calculated for the time period 1850–1973 on the basis of measured cumulative length change, glacier length and estimated ablation at the glacier terminus. For the time period since 1850, permafrost became inactive or disappeared in about 15% of the area originally underlain by permafrost in the whole Upper Engadin region, and mean annual glacier mass balance was calculated as −0.26 to −0.46 m w.e.a−1 for the larger glaciers in the same area. The estimated loss in glacier volume since 1850 lies between 55% and 66% of the original value. With an assumed increase in mean annual air temperature of +3°C, the area of supposed permafrost occurrence would possibly be reduced by about 65% with respect to present-day conditions and only three glaciers would continue to partially exist.

scholarly journals The Mass Balance Of Blue Glacier, Washington, U.S.A. 1956–1986

1990 ◽  
Vol 14 ◽  
pp. 329 ◽  
Author(s):  
Richard L. Armstrong
Keyword(s):  
Mass Balance ◽  
Equilibrium Line Altitude ◽  
The Past ◽  
Winter Snow ◽  
Positive Balance ◽  
Recent Climate ◽  
Strong Gradient ◽  
Accumulation Area Ratio ◽  
Mass Increase ◽  
Measured Mass

Mass-balance data for Blue Glacier are presented for the 31-year period 1956–86. The glacier location is strongly maritime with annual precipitation of 3500 to 5000 mm, most of which falls as winter snow. The low elevation of the glacier results in large amounts of summer ablation and thus significant annual mass exchange. Blue Glacier has been in approximate equilibrium with recent climate during the past 30 years with a slightly positive mean annual net balance of 0.3 m and a terminus advance of 150 m. Comparison with other glaciers in western North America indicates that this pattern of mass increase in response to recent climate is not typical but may be specific to a maritime location. Due to heavy amounts of winter snowfall, an accumulation area ratio of only 0.5 is sufficient to maintain a zero balance on Blue Glacier. A strong gradient of increasing snowfall with elevation contributes to a linear relationship between net balance and elevation throughout the total altitude range of the glacier. This relationship is consistent over the period of record and is not dependent on an overall net positive balance, as the pattern persists even during periods of strongly negative mass balance. A relationship between measured mass balance and equilibrium-line altitude provides a reasonable method to compute mass balance.

scholarly journals Using ground-penetrating radar to image previous years’ summer surfaces for mass-balance measurements

1997 ◽  
Vol 24 ◽  
pp. 355-360 ◽  
Author(s):  
Jack Kohler ◽  
John Moore ◽  
Mike Kennett ◽  
Rune Engeset ◽  
Hallgeir Elvehøy
Keyword(s):  
Dielectric Properties ◽  
Mass Balance ◽  
Ground Penetrating Radar ◽  
Radar Data ◽  
Snow Accumulation ◽  
Ice Surface ◽  
Winter Snow ◽  
Depth Scale ◽  
Ground Penetrating ◽  
Previous Summer

In traditional mass-balance measurements one estimates winter snow accumulation by identifying the depth to the previous summer’s snow or ice surface using a snow probe. This is labor-intensive and unreliable for inhomogeneous summer surfaces. Another method is to image internal reflection horizons using a ground-penetrating radar (GPR), which has advantages in speed and areal coverage over traditional probing. However, to obtain quantitative mass-balance measurements from GPR images one needs to convert the time scale to a depth scale, not a straightforward problem. We compare a GPR section with dielectric profiles and visual stratigraphy of three snow cores, manual probings, and previous mass-balance measurements. We relate changes in snow-core dielectric properties to changes in density and to the travel times of reflecting horizons in the GPR section, and correlate some of these reflecting horizons with previous summer surfaces. We conclude that GPR can be used as a complementary tool in mass-balance measurements, giving a wide areal survey of winter accumulation and net balance for preceding years. However, proper calibration is essential for identifying specific surfaces in the radar data.

scholarly journals A field study of mass balance and hydrology of the West Khangri Nup glacier (Khumbu, Everest).

2020 ◽  
Author(s):  
Giovanni Martino Bombelli ◽  
Daniele Bocchiola ◽  
Federica Camin ◽  
Paolo Maria Ossi
Keyword(s):  
Mass Balance ◽  
Original Data ◽  
Snow Accumulation ◽  
Landsat Images ◽  
The West ◽  
Field Surveys ◽  
Ice Melt ◽  
Field Campaigns ◽  
Set Up ◽  
Ice Water

<p>Depiction of glaciers’ dynamics in the high altitudes of Himalaya, and hydrological fluxes therein is often limited, and yet necessary to assess their contribution to overall water budget in the downstream areas. Information about glaciers in these remote regions is often based on satellite data, which routinely document the retreat or advance of ice-covered areas, while volume changes are less easy to quantify, and require local assessment of weather, and hydrology. <br>Here, we report investigation of snow accumulation, ice melt, and mass balance of the West Khangri Nup (WKN) glacier (mean altitude 5494 m a.s.l., 0.23 km<sup>2</sup>), a part of the Khumbu glacier in the Everest region. The glaciers of the area have experienced negative mass balances in the last three decades, and accordingly investigation of their recent, and prospective dynamics seems necessary. <br>Weather, glaciological, snow pits, hydrologic, and isotopic data gathered during some field campaigns (2010-2014) on the glacier, and at the EVK2CNR pyramid site are used here to set up the Poli-Hydro glacio-hydrological model, to depict ice and snow melt and hydrological flows, and investigate seasonal snow dynamics on this high region of the glacier.   <br>Coupling ice ablation data, and Poli-Hydro simulation for ca. 5 years (January 2010-June 2014), we estimated that WKN depleted ca. -10.46 m of ice water equivalent IWE (i.e. annually ca. -2.32 m IWEy<sup>-1</sup>). Using then snowpack density, and isotopic (δ<sup>18</sup>O) profiles on the WKN, we demonstrate that local snowpack during field surveys was recent (Fall-Winter 2013-2014), and that significant snow accumulation did not occur recently. Analysis of recent snow cover from LANDSAT images also confirms snow dynamics as depicted. <br>We present original data and results, and complement present studies covering glaciers’ mass balance, and investigation of accumulation zones in the Everest region, and the Himalayas, also potentially helpful in the assessment of future dynamics under ongoing climate change.     </p>

scholarly journals Mountain glaciers of NE Asia in the near future: a projection based on climate-glacier systems' interaction

2008 ◽  
Vol 2 (1) ◽  
pp. 1-21 ◽  
Author(s):  
M. D. Ananicheva ◽  
A. N. Krenke ◽  
E. Hanna
Keyword(s):  
Mass Balance ◽  
Morphological Structure ◽  
Equilibrium Line Altitude ◽  
Late 20Th Century ◽  
Simple Method ◽  
Mountain Glaciers ◽  
Glacier System ◽  
Cold Area ◽  
Glacier Ice ◽  
Meteorological Observations

Abstract. In this study we consider contrasting continental (Orulgan, Suntar-Khayata and Chersky ranges located in the Pole of Cold area at the contact of Atlantic and Pacific influences) and maritime (Kamchatka under the Pacific influence) Russian glacier systems. Our purpose is to present a simple method for the projection of change of the main parameters of these glacier systems with climate change. To achieve this aim, we constructed vertical profiles of mass balance (accumulation and ablation) based both on meteorological observations for the mid to late 20th century and an ECHAM4 GCM scenario for 2040–2069. The observations and scenario were used for defining the recent and future equilibrium line altitude (ELA) for each glacier system. The altitudinal distributions of the areas covered with glacier ice were determined for present and future states of the glacier systems, taking into account the correlation of the change of the ELA and glacier-termini levels. We also give estimates of the possible changes of the areas and morphological structure of North-eastern Asia glacier systems and their mass balance characteristics from the ECHAM4 scenario. Finally, we compare characteristics of the continental and maritime glacier systems stability under conditions of global warming.

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