scholarly journals Isotopic Composition of Glacier Ice and Meltwater in the Arid Parts of the Altai Mountains (Central Asia)

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 252
Author(s):  
Dmitriy Bantcev ◽  
Dmitriy Ganyushkin ◽  
Anton Terekhov ◽  
Alexey Ekaykin ◽  
Igor Tokarev ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Snow Accumulation ◽  
Altai Mountains ◽  
Study Region ◽  
Local Climate ◽  
Seasonal Snow ◽  
Research Areas ◽  
Glacier Runoff ◽  
Glacier Ice ◽  
Isotopic Separation

The objective of this study is to reveal the isotopic composition of ice and meltwater in glaciated regions of South-Eastern Altai. The paper depicts differences between the isotopic composition of glacier ice from several types of glaciers and from various locations. Detected differences between the isotopic composition of glacier ice in diversified parts of the study region are related to local climate patterns. Isotopic composition of meltwater and isotopic separation for glacier rivers runoff showed that in the Tavan-Bogd massif, seasonal snow participates more in the formation of glacier runoff due to better conditions for snow accumulation on the surface of glaciers. In other research areas pure glacier meltwater prevails in runoff.

scholarly journals Formation of glacier runoff on the northern slope of Tavan Bogd mountain massif based on stable isotopes data

2018 ◽  
Vol 58 (3) ◽  
pp. 333-342 ◽  
Author(s):  
D. V. Bantsev ◽  
D. A. Ganyushkin ◽  
K. V. Chistyakov ◽  
A. A. Ekaykin ◽  
I. V. Tokarev ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Isotopic Composition ◽  
Summer Precipitation ◽  
Morphological Type ◽  
Early Summer ◽  
Glacier Surface ◽  
Glacier Runoff ◽  
Different Seasons ◽  
Glacier Ice

This investigation is based on measurements of stable isotopes concentrations (δD and δ18О) in water, snow and ice samples. Glaciers are composed of ice, snow, and fi n of atmospheric origin. The isotopic composition of these components is different, so when melting they form the melted glacial water with different isotope characteristics. Summer precipitation contains the heaviest isotopes, but only a small part of them remains on the glacier. The average isotopic composition of glacier ice represents the average composition of precipitation that accumulates on it. However, snow and fi n of different seasons can occur on the glacier surface, the isotopic composition of which differs from the isotopic composition of glacier ice. At different times of the ablation season different parts of the glacier melt, therefore the isotopic composition of melt waters will be different. Differences in the isotopic composition of the major runoff-forming components on the Northern slopes of the massif Tabyn-Bogdo-Ola had been identified. A part of melting ice in the formation of the runoff on this massif is determined by estimation of the isotopic composition of snow, ice, and fi n on different glaciers of this region. The average δ18О of snow on the glacier surface is −11.9‰, and this snow can be attributed to the precipitation fallen in late spring or early summer. Measured average isotopic composition of precipitation (δ18О = −11.9‰) was compared with the online calculator of the isotope content in precipitation (OIPC). The isotopic composition of glacial melt waters on the Northern macro-slope in the middle of July 2015 (δ18О = −15.3‰) differs from the isotopic composition of the territory of the Mongolian part of the massif (δ18О = −17.4‰) obtained from results of the analysis of eight samples taken at different edges of the glaciers at the beginning of August 2013. Isotopic separation shows important role of summer snow in feeding the glacial rivers of the massif even in the middle of the ablation season, especially for glaciers in the central part of the massif. The role of seasonal snow in feeding the glacier streams depends on the morphological type of glacier. It is maximum for corrie glaciers and minimum for the valley ones.

Seasonal variations in the properties and structural composition of sea ice and snow cover in the Bellingshausen and Amundsen Seas, Antarctica

1997 ◽  
Vol 43 (143) ◽  
pp. 138-151 ◽  
Author(s):  
M. O. Jeffries ◽  
K. Morris ◽  
W.F. Weeks ◽  
A. P. Worby
Keyword(s):  
Sea Ice ◽  
Isotopic Composition ◽  
Snow Cover ◽  
Sea Water ◽  
Ice Cores ◽  
Ice Cover ◽  
Snow Accumulation ◽  
Ice Formation ◽  
Frazil Ice ◽  
Core Sets

AbstractSixty-three ice cores were collected in the Bellingshausen and Amundsen Seas in August and September 1993 during a cruise of the R.V. Nathaniel B. Palmer. The structure and stable-isotopic composition (18O/16O) of the cores were investigated in order to understand the growth conditions and to identify the key growth processes, particularly the contribution of snow to sea-ice formation. The structure and isotopic composition of a set of 12 cores that was collected for the same purpose in the Bellingshausen Sea in March 1992 are reassessed. Frazil ice and congelation ice contribute 44% and 26%, respectively, to the composition of both the winter and summer ice-core sets, evidence that the relatively calm conditions that favour congelation-ice formation are neither as common nor as prolonged as the more turbulent conditions that favour frazil-ice growth and pancake-ice formation. Both frazil- and congelation-ice layers have an av erage thickness of 0.12 m in winter, evidence that congelation ice and pancake ice thicken primarily by dynamic processes. The thermodynamic development of the ice cover relies heavily on the formation of snow ice at the surface of floes after sea water has flooded the snow cover. Snow-ice layers have a mean thickness of 0.20 and 0.28 m in the winter and summer cores, respectively, and the contribution of snow ice to the winter (24%) and summer (16%) core sets exceeds most quantities that have been reported previously in other Antarctic pack-ice zones. The thickness and quantity of snow ice may be due to a combination of high snow-accumulation rates and snow loads, environmental conditions that favour a warm ice cover in which brine convection between the bottom and top of the ice introduces sea water to the snow/ice interface, and bottom melting losses being compensated by snow-ice formation. Layers of superimposed ice at the top of each of the summer cores make up 4.6% of the ice that was examined and they increase by a factor of 3 the quantity of snow entrained in the ice. The accumulation of superimposed ice is evidence that melting in the snow cover on Antarctic sea-ice floes ran reach an advanced stage and contribute a significant amount of snow to the total ice mass.

scholarly journals Accumulation and Temperature on The Inland Ice of North Greenland, 1959

1961 ◽  
Vol 3 (30) ◽  
pp. 1017-1044 ◽  
Author(s):  
Chester C. Langway
Keyword(s):  
Snow Accumulation ◽  
Surface Slope ◽  
Empirical Correlations ◽  
Altitude Gradient ◽  
Local Climate ◽  
The Mean ◽  
Inland Ice ◽  
Deep Pits ◽  
North Greenland ◽  
Linear Trends

AbstractTwelve deep pits (5 to 5.5 m.) revealed between 6 and 13 years of snow accumulation. The results show an average net accumulation of 18.5 g./cm.2per year. Accumulation decreases inland at a mean rate of 1.5 g./cm.2per 100 m. rise in elevation. Temperature measurements at 100 m. in all pits give a mean temperature-altitude gradient of 0.77° C. per 100 m. Evidence of melt was observed in all pits, the most pronounced melt occurring in 1954. The mean density reflects the local climate. Other empirical correlations of these data show linear trends that vary systematically with surface slope and local climate.

scholarly journals Attribution of high resolution streamflow trends in Western Austria – an approach based on climate and discharge station data

2015 ◽  
Vol 19 (3) ◽  
pp. 1225-1245 ◽  
Author(s):  
C. Kormann ◽  
T. Francke ◽  
M. Renner ◽  
A. Bronstert
Keyword(s):  
Freezing Point ◽  
Snow Accumulation ◽  
Lower Altitude ◽  
Study Region ◽  
Daily Streamflow ◽  
Streamflow Data ◽  
The One ◽  
Streamflow Trend ◽  
Streamflow Trends

Abstract. The results of streamflow trend studies are often characterized by mostly insignificant trends and inexplicable spatial patterns. In our study region, Western Austria, this applies especially for trends of annually averaged runoff. However, analysing the altitudinal aspect, we found that there is a trend gradient from higher-altitude to lower-altitude stations, i.e. a pattern of mostly positive annual trends at higher stations and negative ones at lower stations. At mid-altitudes, the trends are mostly insignificant. Here we hypothesize that the streamflow trends are caused by the following two main processes: on the one hand, melting glaciers produce excess runoff at higher-altitude watersheds. On the other hand, rising temperatures potentially alter hydrological conditions in terms of less snowfall, higher infiltration, enhanced evapotranspiration, etc., which in turn results in decreasing streamflow trends at lower-altitude watersheds. However, these patterns are masked at mid-altitudes because the resulting positive and negative trends balance each other. To support these hypotheses, we attempted to attribute the detected trends to specific causes. For this purpose, we analysed trends of filtered daily streamflow data, as the causes for these changes might be restricted to a smaller temporal scale than the annual one. This allowed for the explicit determination of the exact days of year (DOYs) when certain streamflow trends emerge, which were then linked with the corresponding DOYs of the trends and characteristic dates of other observed variables, e.g. the average DOY when temperature crosses the freezing point in spring. Based on these analyses, an empirical statistical model was derived that was able to simulate daily streamflow trends sufficiently well. Analyses of subdaily streamflow changes provided additional insights. Finally, the present study supports many modelling approaches in the literature which found out that the main drivers of alpine streamflow changes are increased glacial melt, earlier snowmelt and lower snow accumulation in wintertime.

scholarly journals δD – δ18O Relationships in Ice Formed by Subglacial Freezing: Paleoclimatic Implications

1985 ◽  
Vol 31 (109) ◽  
pp. 229-232 ◽  
Author(s):  
R. A. Souchez ◽  
J. M. de Groote
Keyword(s):  
Computer Simulation ◽  
Isotopic Composition ◽  
Ice Sheets ◽  
Ice Cores ◽  
System Model ◽  
Polar Ice ◽  
Bottom Part ◽  
Basal Ice ◽  
Polar Ice Sheets ◽  
Glacier Ice

AbstractA freezing slope, distinct from that of precipitation, is displayed on a δD–δ18O diagram by basal ice in different circumstances. However, if the subglacial reservoir allowed to freeze is mixed in the course of time with an input having a lighter isotopic composition, basal ice cannot be distinguished from glacier ice in terms of slope. Such a situation is encountered at the base of Grubengletscher and is indicated by a computer simulation using the open-system model of Souchez and Jouzel (1984). Suggested implications for the paleoclimatic interpretation of deep ice cores recovered from the bottom part of polar ice sheets are given.

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.

Temporal Variations of Isotopic Composition of Glacier-River Water During Summer: Observations at Austre Okstindbreen, Okstindan, Norway

1988 ◽  
Vol 34 (118) ◽  
pp. 309-317 ◽  
Author(s):  
Wilfred H. Theakstone
Keyword(s):  
Isotopic Composition ◽  
River Water ◽  
Temporal Variations ◽  
Surface Melting ◽  
Base Flow ◽  
Strongly Correlated ◽  
Drainage Systems ◽  
Fine Weather ◽  
Air Temperatures ◽  
Glacier Ice

AbstractThe isotopic composition of river water discharging from the Norwegian glacier, Austre Okstindbreen, in summer varies on both daily and longer-term scales. Most δ18o values of samples from the principal river are within the range −12.5 to −14.0‰). Because new snow tends to be relatively depleted of 8180, water leaving the glacier early in the summer has low δ18O values. Subsequently, values rise as contributions of old snow, glacier ice, and their melt waters, which are isotopically heavier (median δ18O values generally above −12.0‰) dilute the δ18O depleted base-flow component of discharge, a mixture of waters with different histories of formation, storage, and transit. Accumulation-area melting contributes significantly to river discharge. Towards the end of the summer, as surface melting declines, δ18O values tend to fall. Between-year differences of within-summer trends reflect differences of development of the glacier’s drainage systems. The drainage systems are affected by outbursts from a glacier-dammed lake. During fine weather, δ18ovariations follow the diurnal cycle of surface melting: they are strongly correlated with, but lag behind, air temperatures. Perturbations during rainfall cannot be explained simply in terms of the isotopic composition of the precipitation, since low values may be associated with isotopically heavy rainfall. Displacement of water previously stored within or below the glacier may account for the anomaly. Contrasts of composition characterize different rivers leaving the glacier, because the relative contributions of various water sources differ.

scholarly journals Isotopic Fractionation at the Base of Polar and Sub-Polar Glaciers

1986 ◽  
Vol 32 (112) ◽  
pp. 475-485 ◽  
Author(s):  
G.S. Boulton ◽  
U. Spring
Keyword(s):  
Isotopic Composition ◽  
Large Scale ◽  
Isotopic Fractionation ◽  
Strong Support ◽  
Sharp Change ◽  
West Antarctica ◽  
Tectonic Structures ◽  
Melt Water ◽  
Glacier Ice ◽  
Hydrological System

AbstractThe melting of ice and the subsequent production of regelation ice from the melt water in a large-scale closed system beneath sub-polar and polar glaciers produces progressive fractionation between the melt water and the regelation ice derived from it. A theory is developed which predicts the change of isotopic composition in regelation ice in a subglacial zone of freezing and in the water from which it is derived. The theory is tested against data from the Byrd Station bore hole in West Antarctica, and applied to explain features of the isotopic composition in several other glaciers where thick sequences of regelation ice have formed.The principal conclusions are:1. Basal isotopic profiles can be used to reconstruct important features of a glacier’s hydrological system.2. Isotopic profiles in basal regelation ice do not simply reflect isotopic characteristics of ancient atmospheres but also, by using the theory, some of the isotopic characteristics of the normal glacier ice which was destroyed by melting and subsequently produced regelation ice can be reconstructed. Basal regelation ice at Byrd Station reflects an original ice source isotopically colder than the overlying normal ice, and may have formed during the penultimate glacial period, equivalent to stage 6 of the oceanic record.3. The subglacially derived debris typically found in basal regelation ice gives a complex strain response to a changing pattern of stresses produced by flow over an irregular subjacent bed. Thus, complex tectonic structures in this ice produce highly variable isotopic profiles. However, its gross isotopic characteristics can still be used to reconstruct some of its history. A sharp change in isotopic values tends to occur at the upper limit of basal regelation ice, the nature of which depends on the style and thickness of tectonic disturbance.4. Isotopic profiles in basal ice can be used to distinguish normal glacier ice from regelation ice, and give strong support to the view that regelation is the major process by which debris is incorporated into the base of a glacier.

Prediction of seasonal snow accumulation in cold climate forests

2002 ◽  
Vol 16 (18) ◽  
pp. 3543-3558 ◽  
Author(s):  
J. W. Pomeroy ◽  
D. M. Gray ◽  
N. R. Hedstrom ◽  
J. R. Janowicz
Keyword(s):  
Snow Accumulation ◽  
Cold Climate ◽  
Seasonal Snow

scholarly journals Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

2011 ◽  
Vol 5 (4) ◽  
pp. 1099-1113 ◽  
Author(s):  
S. Gascoin ◽  
C. Kinnard ◽  
R. Ponce ◽  
S. Lhermitte ◽  
S. MacDonell ◽  
...  
Keyword(s):  
Quantitative Assessment ◽  
Hydrological Regime ◽  
Snow Accumulation ◽  
Glacier Area ◽  
Glacier Surface ◽  
Headwater Catchments ◽  
Glacier Meltwater ◽  
Glacier Runoff ◽  
Change Impact ◽  
The Mean

Abstract. Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11 % allows the estimation of the mean annual glacier contribution to discharge between 2003/2004 and 2007/2008 hydrological years. In addition, direct manual measurements of glacier runoff were conducted in summer at the snouts of four glaciers, which provide the instantaneous contribution of glacier meltwater to stream runoff during summer. The results show that the mean annual glacier contribution to streamflow ranges between 3.3 and 23 %, which is greater than the glaciated fraction of the catchments. We argue that glacier contribution is partly enhanced by the effect of snowdrift from the non-glacier area to the glacier surface. Glacier mass loss is evident over the study period, with a mean of −0.84 m w.e. yr−1 for the period 2003/2004–2007/2008, and also contributes to increase glacier runoff. An El Niño episode in 2002 resulted in high snow accumulation, modifying the hydrological regime and probably reducing the glacier contribution in favor of seasonal snowmelt during the subsequent 2002/2003 hydrological year. At the hourly timescale, summertime glacier contributions are highly variable in space and time, revealing large differences in effective melting rates between glaciers and glacierets (from 1 mm w.e. h−1 to 6 mm w.e. h−1).

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