scholarly journals Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014

2017 ◽  
Vol 11 (1) ◽  
pp. 191-215 ◽  
Author(s):  
Torbjørn Ims Østby ◽  
Thomas Vikhamar Schuler ◽  
Jon Ove Hagen ◽  
Regine Hock ◽  
Jack Kohler ◽  
...  
Keyword(s):  
Mass Balance ◽  
Linear Trend ◽  
Model Performance ◽  
Marked Change ◽  
Ice Cores ◽  
High Arctic ◽  
Reanalysis Data ◽  
Svalbard Archipelago ◽  
Summer Temperatures

Abstract. Estimating the long-term mass balance of the high-Arctic Svalbard archipelago is difficult due to the incomplete geodetic and direct glaciological measurements, both in space and time. To close these gaps, we use a coupled surface energy balance and snow pack model to analyse the mass changes of all Svalbard glaciers for the period 1957–2014. The model is forced by ERA-40 and ERA-Interim reanalysis data, downscaled to 1 km resolution. The model is validated using snow/firn temperature and density measurements, mass balance from stakes and ice cores, meteorological measurements, snow depths from radar profiles and remotely sensed surface albedo and skin temperatures. Overall model performance is good, but it varies regionally. Over the entire period the model yields a climatic mass balance of 8.2 cm w. e.  yr−1, which corresponds to a mass input of 175 Gt. Climatic mass balance has a linear trend of −1.4 ± 0.4 cm w. e.  yr−2 with a shift from a positive to a negative regime around 1980. Modelled mass balance exhibits large interannual variability, which is controlled by summer temperatures and further amplified by the albedo feedback. For the recent period 2004–2013 climatic mass balance was −21 cm w. e.  yr−1, and accounting for frontal ablation estimated by Błaszczyk et al.(2009) yields a total Svalbard mass balance of −39 cm w. e.  yr−1 for this 10-year period. In terms of eustatic sea level, this corresponds to a rise of 0.037 mm yr−1. Refreezing of water in snow and firn is substantial at 22 cm w. e.  yr−1 or 26 % of total annual accumulation. However, as warming leads to reduced firn area over the period, refreezing decreases both absolutely and relative to the total accumulation. Negative mass balance and elevated equilibrium line altitudes (ELAs) resulted in massive reduction of the thick (>  2 m) firn extent and an increase in the superimposed ice, thin (<  2 m) firn and bare ice extents. Atmospheric warming also leads to a marked change in the thermal regime, with cooling of the glacier mid-elevation and warming in the ablation zone and upper firn areas. On the long-term, by removing the thermal barrier, this warming has implications for the vertical transfer of surface meltwater through the glacier and down to the base, influencing basal hydrology, sliding and thereby overall glacier motion.

scholarly journals Diagnosing the decline in climatic mass balance of glaciers in Svalbard over 1957–2014

2016 ◽  
Author(s):  
Torbjørn Ims Østby ◽  
Thomas Vikhamar Schuler ◽  
Jon Ove Hagen ◽  
Regine Hock ◽  
Jack Kohler ◽  
...  
Keyword(s):  
Mass Balance ◽  
Linear Trend ◽  
Model Performance ◽  
Ice Cores ◽  
High Arctic ◽  
Reanalysis Data ◽  
Svalbard Archipelago ◽  
Resolution Model ◽  
Summer Temperatures ◽  
Frontal Ablation

Abstract. Longterm mass balance of all glaciers of the high Arctic Svalbard archipelago is difficult to achieve due to spatial and temporal incompleteness of geodetic and direct glaciological measurements. To close these gaps, we use a coupled surface energy balance and snow pack model to analyze Svalbard glacier mass changes and its evolution for the period 1957–2014. The model is forced by ERA-40 and ERA-Interim reanalysis data downscaled to 1 km resolution. Model validation is based on measured snow/firn temperature and density, mass balance from stakes and ice cores, meteorological measurements, snow depths from radar profiles and remotely sensed surface albedo and skin temperatures. Overall model performance is good, but varies regionally. Over the entire period the model yields a climatic mass balance of 8.2 cm w.e. yr−1 which correspond to a mass surplus (excluding frontal ablation) of 175 Gt. Climatic mass balance has a linear trend of −1.4 &amp;pm; 0.4 cm w.e. yr−2 with a shift from a positive to negative regime around 1980. Modeled mass balance exhibit large interannual variability, which is controlled by summer temperatures and further amplified by albedo feedback. For the period 2004–2013 climatic mass balance was −21 cm w.e. yr−1, and accounting for frontal ablation estimated by Błaszczyk et al. (2009) yields a total Svalbard mass balance of −39 cm w.e. yr−1 for this 10 year period. In terms of eustatic sea level, this corresponds to a rise of 0.037 mm yr−1. Refreezing of water in snow and firn is substantial at 22 cm w.e. yr−1, or 26 % of the accumulation. However, as warming lead to reduced firn area over the period, refreezing decrease both absolutely and relative to the mass budget. Negative mass balance and elevated equilibrium lines result in a massive loss of the thick firn (> 2 m) extent and an increase of the superimposed ice, thin firn (

scholarly journals A reconstruction of annual mass balances of Austria’s glaciers from 1969 to 1998

2011 ◽  
Vol 52 (59) ◽  
pp. 127-134 ◽  
Author(s):  
J. Abermann ◽  
M. Kuhn ◽  
A. Fischer
Keyword(s):  
Mass Balance ◽  
Reanalysis Data ◽  
Mass Balances ◽  
Lower Altitude ◽  
Surface Mass ◽  
Tuning Parameters ◽  
Degree Day ◽  
Covered Area ◽  
Summer Temperatures

AbstractAnnual glacier mass balances are reconstructed for 96% of the Austrian glacier-covered area (451 of 470 km2) between 1969 and 1998. The volume change derived from two complete glacier inventories (1969 and 1998) serves as the boundary condition that is aimed to be reproduced. ERA-40 reanalysis data as well as a gridded precipitation dataset (HISTALP) are used to drive a positive degree-day (PDD) model. The results are verified with four independent long-term mass-balance series. The spatial and vertical distribution of the tuning parameters is altered in order to reproduce the measured mean annual surface mass balances of selected glaciers, and a strong correlation is found between the median elevation of a glacier and the degree-day factor (DDF) at this elevation. This result implies that the lower a glacier’s median elevation is, the less melt occurs at a given elevation and temperature. We attribute this to the fact that lower-altitude glaciers are generally those with more accumulation, which leads to later exposure of bare ice and a longer period of high-albedo snow cover. A further improvement of the model was achieved by making DDF a function of time as well as space. The results indicate that mean DDFs generally increase for a given date over a sequence of consecutive negative mass-balance years, which probably reflects the reduction in albedo related to that. Finally, the major drivers of the observed mass-balance evolution are investigated: summer PDD sums correlate significantly better with the observed mass-balance changes than annual PDD sums or precipitation do. This implies that annual mass balances in the study area are governed by summer temperatures.

scholarly journals The impact of Saharan dust and black carbon on albedo and long-term glacier mass balance

2015 ◽  
Vol 9 (1) ◽  
pp. 1133-1175 ◽  
Author(s):  
J. Gabbi ◽  
M. Huss ◽  
A. Bauder ◽  
F. Cao ◽  
M. Schwikowski
Keyword(s):  
Mass Balance ◽  
Black Carbon ◽  
Mineral Dust ◽  
Ice Cores ◽  
Swiss Alps ◽  
Saharan Dust ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
The Impact

Abstract. Light-absorbing impurities in snow and ice control glacier melt as shortwave radiation represents the main component of the surface energy balance. Here, we investigate the long-term effect of snow impurities, i.e. Saharan dust and black carbon (BC), on albedo and glacier mass balance. The analysis was performed over the period 1914–2014 for two sites on Claridenfirn, Swiss Alps, where an outstanding 100 year record of seasonal mass balance measurements is available. Information on atmospheric deposition of mineral dust and BC over the last century was retrieved from two firn/ice cores of high-alpine sites. A combined mass balance and snow/firn layer model was employed to assess the dust/BC-albedo feedback. Compared to pure snow conditions, the presence of Saharan dust and BC lowered the mean annual albedo by 0.04–0.06 and increased melt by 15–19% on average depending on the location on the glacier. BC clearly dominated absorption which is about three times higher than that of mineral dust. The upper site has experienced mainly positive mass balances and impurity layers were continuously buried whereas at the lower site, surface albedo was more strongly influenced by re-exposure of dust-enriched layers due to frequent years with negative mass balances.

Glaciers in the High Arctic and recent environmental change

1995 ◽  
Vol 352 (1699) ◽  
pp. 321-334 ◽  
Keyword(s):  
Mass Balance ◽  
Climate Warming ◽  
Meteorological Data ◽  
Ice Cores ◽  
High Arctic ◽  
Ice Age ◽  
Geological Evidence ◽  
Recent Climate ◽  
Severnaya Zemlya ◽  
Energy Balance Approach

High Arctic climate change over the last few hundred years includes the relatively cool Little Ice Age (LIA), followed by warming over the last hundred years or so. Meteorological data from the Eurasian High Arctic (Svalbard, Franz Josef Land, Severnaya Zemlya) and Canadian High Arctic islands are scarce before the mid-20th century, but longer records from Svalbard and Greenland show warming from about 1910-1920. Logs of Royal Navy ships in the Canadian Northwest Passage in the 1850s indicate temperatures cooler by 1-2.5 °C during the LIA. Other evidence of recent trends in High Arctic temperatures and precipitation is derived from ice cores, which show cooler temperatures (by 2-3 °C) for several hundred years before 1900, with high interdecadal variability. The proportion of melt layers in ice cores has also risen over the last 70-130 years, indicating warming. There is widespread geological evidence of glacier retreat in the High Arctic since about the turn of the century linked to the end of the LIA. An exception is the rapid advance of some surge-type ice masses. Mass balance measurements on ice caps in Arctic Canada, Svalbard and Severnaya Zemlya since 1950 show either negative or near-zero net balances, suggesting glacier response to recent climate warming. Glacier-climate links are modelled using an energy balance approach to predict glacier response to possible future climate warming, and cooler LIA temperatures. For Spitsbergen glaciers, a negative shift in mass balance of about 0.5 m a -1 is predicted for a 1 °C warming. A cooling of about 0.6 °C, or a 23% precipitation increase, would produce an approximately zero net mass balance. A ‘greenhouse-induced’ warming of 1 °C in the High Arctic is predicted to produce a global sea-level rise of 0.063 mm a -1 from ice cap melting.

scholarly journals 40 years High Arctic climatological dataset of the Polish Polar Station Hornsund (SW Spitsbergen, Svalbard)

2019 ◽  
Author(s):  
Tomasz Wawrzyniak ◽  
Marzena Osuch
Keyword(s):  
Environmental Changes ◽  
High Arctic ◽  
The Arctic ◽  
Data Series ◽  
Annual Data ◽  
Climate Data ◽  
Atlantic Sector ◽  
Svalbard Archipelago

Abstract. The article presents the climatological dataset from the Polish Polar Station Hornsund located in the SW part of Spitsbergen - the biggest island of the Svalbard Archipelago. Due to a general lack of long-term in situ measurements and observations, the high Arctic remains one of the largest climate‐data deficient regions on the Earth, so described series is of unique value. To draw conclusions on the climatic changes in the Arctic, it is necessary to analyse the long-term series of continuous, systematic, in situ observations from different locations and comparing the corresponding data, rather than rely on the climatic simulations only. In recent decades, rapid environmental changes occurring in the Atlantic sector of the Arctic are reflected in the data series collected by the operational monitoring conducted at the Hornsund Station. We demonstrate the results of the 40 years-long series of observations. Climatological mean values or totals are given, and we also examined the variability of meteorological variables at monthly and annual scale using the modified Mann-Kendall test for trend and Sen’s method. The relevant daily, monthly, and annual data are provided on the PANGAEA repository (https://doi.org/10.1594/PANGAEA.909042, Wawrzyniak and Osuch, 2019).

scholarly journals Dating the ice of Gauligletscher, Switzerland, based on surface radionuclide contamination and ice flow modeling

2020 ◽  
Author(s):  
Guillaume Jouvet ◽  
Stefan Röllin ◽  
Hans Sahli ◽  
José Corcho ◽  
Lars Gnägi ◽  
...  
Keyword(s):  
Mass Balance ◽  
Ice Core ◽  
Ice Cores ◽  
Balance Model ◽  
Flow Modeling ◽  
Ice Flow ◽  
Radionuclide Contamination ◽  
Glacier Ice ◽  
Surface Ice

Abstract. In the 1950s and '60s, specific radionuclides were released into the atmosphere as a result of nuclear weapons testing. This radioactive fallout left its signature on the accumulated layers of glaciers worldwide, thus providing a tracer for ice particles traveling within the gravitational ice flow and being released into the ablation zone. For surface ice dating purposes, we analyze here the activity of 239Pu, 240Pu and 236U radionuclides derived from more than 200 ice samples collected along five flowlines at the surface of Gauligletscher, Switzerland. It was found that contaminations appear band-wise along most of the sampled lines, revealing a V-shaped profile consistent with the ice flow field already observed. Similarities to activities found in ice cores permit the isochronal lines at the glacier from 1960 and 1963 to be identified. Hence this information is used to fine-tune an ice flow/mass balance model, and to accurately map the age of the entire glacier ice. Our results indicate the strong potential for combining radionuclide contamination and ice flow modeling in two different ways. First, such tracers provide unique information on the long-term ice motion of the entire glacier (and not only at its surface), and on the long-term mass balance, and therefore offer an extremely valuable data tool for calibrating ice flows within a model. Second, the dating of surface ice is highly relevant when conducting "horizontal ice core sampling", i.e., when taking chronological samples of surface ice from the distant past, without having to perform expensive and logistically complex deep ice-core drilling. In conclusion, our results show that an airplane which crash-landed on the Gauligletscher in 1946 will likely soon be released from the ice close to the place where pieces have emerged in recent years, thus permitting the prognosis given in an earlier model to be revised considerably.

scholarly journals A 40-year High Arctic climatological dataset of the Polish Polar Station Hornsund (SW Spitsbergen, Svalbard)

2020 ◽  
Vol 12 (2) ◽  
pp. 805-815 ◽  
Author(s):  
Tomasz Wawrzyniak ◽  
Marzena Osuch
Keyword(s):  
Environmental Changes ◽  
High Arctic ◽  
The Arctic ◽  
Data Series ◽  
Annual Data ◽  
Climate Data ◽  
Atlantic Sector ◽  
Svalbard Archipelago

Abstract. The article presents the climatological dataset from the Polish Polar Station Hornsund located in the southwest part of Spitsbergen – the biggest island of the Svalbard archipelago. Due to a general lack of long-term in situ measurements and observations, the High Arctic remains one of the largest climate-data-deficient regions on the Earth. Therefore, the described time series of observations in this paper are of unique value. To draw conclusions on the climatic changes in the Arctic, it is necessary to analyse and compare the long-term series of continuous, in situ observations from different locations, rather than relying on the climatic simulations only. In recent decades, rapid environmental changes occurring in the Atlantic sector of the Arctic are reflected in the data series collected by the operational monitoring conducted at the Hornsund station. We demonstrate the results of the 40-year-long series of observations. Climatological mean values or totals are given, and we also examined the variability of meteorological variables at monthly and annual scale using the modified Mann–Kendall test for trend and Sen's method. The relevant daily, monthly, and annual data are provided on the PANGAEA repository (https://doi.org/10.1594/PANGAEA.909042, Wawrzyniak and Osuch, 2019).

scholarly journals Mapping the age of ice of Gauligletscher combining surface radionuclide contamination and ice flow modeling

2020 ◽  
Vol 14 (11) ◽  
pp. 4233-4251
Author(s):  
Guillaume Jouvet ◽  
Stefan Röllin ◽  
Hans Sahli ◽  
José Corcho ◽  
Lars Gnägi ◽  
...  
Keyword(s):  
Mass Balance ◽  
Ice Core ◽  
Ice Cores ◽  
Balance Model ◽  
Flow Modeling ◽  
Ice Flow ◽  
Radionuclide Contamination ◽  
Glacier Ice ◽  
Surface Ice

Abstract. In the 1950s and 1960s, specific radionuclides were released into the atmosphere as a result of nuclear weapons testing. This radioactive fallout left its signature on the accumulated layers of glaciers worldwide, thus providing a tracer for ice particles traveling within the gravitational ice flow and being released into the ablation zone. For surface ice dating purposes, we analyze here the activity of 239Pu, 240Pu and 236U radionuclides derived from more than 200 ice samples collected along five flowlines at the surface of Gauligletscher, Switzerland. It was found that contaminations appear band-wise along most of the sampled lines, revealing a V-shaped profile consistent with the ice flow field already observed. Similarities to activities found in ice cores permit the isochronal lines at the glacier from 1960 and 1963 to be identified. Hence this information is used to fine-tune an ice flow/mass balance model, and to accurately map the age of the entire glacier ice. Our results indicate the strong potential for combining radionuclide contamination and ice flow modeling in two different ways. First, such tracers provide unique information on the long-term ice motion of the entire glacier (and not only at its surface), and on the long-term mass balance, and therefore offer an extremely valuable data tool for calibrating ice flows within a model. Second, the dating of surface ice is highly relevant when conducting “horizontal ice core sampling”, i.e., when taking chronological samples of surface ice from the distant past, without having to perform expensive and logistically complex deep ice-core drilling. In conclusion, our results show that an airplane which crash-landed on the Gauligletscher in 1946 will likely soon be released from the ice close to the place where pieces have emerged in recent years, thus permitting the prognosis given in an earlier model to be revised considerably.

scholarly journals Mass balance of the Antarctic ice sheet 1992–2016: reconciling results from GRACE gravimetry with ICESat, ERS1/2 and Envisat altimetry

2021 ◽  
pp. 1-27
Author(s):  
H. Jay Zwally ◽  
John W. Robbins ◽  
Scott B. Luthcke ◽  
Bryant D. Loomis ◽  
Frédérique Rémy
Keyword(s):  
Mass Balance ◽  
Antarctic Peninsula ◽  
East Antarctica ◽  
Mantle Material ◽  
West Antarctica ◽  
Mantle Viscosity ◽  
Grounding Line ◽  
The Antarctic ◽  
Total Gain

Abstract GRACE and ICESat Antarctic mass-balance differences are resolved utilizing their dependencies on corrections for changes in mass and volume of the same underlying mantle material forced by ice-loading changes. Modeled gravimetry corrections are 5.22 times altimetry corrections over East Antarctica (EA) and 4.51 times over West Antarctica (WA), with inferred mantle densities 4.75 and 4.11 g cm−3. Derived sensitivities (Sg, Sa) to bedrock motion enable calculation of motion (δB0) needed to equalize GRACE and ICESat mass changes during 2003–08. For EA, δB0 is −2.2 mm a−1 subsidence with mass matching at 150 Gt a−1, inland WA is −3.5 mm a−1 at 66 Gt a−1, and coastal WA is only −0.35 mm a−1 at −95 Gt a−1. WA subsidence is attributed to low mantle viscosity with faster responses to post-LGM deglaciation and to ice growth during Holocene grounding-line readvance. EA subsidence is attributed to Holocene dynamic thickening. With Antarctic Peninsula loss of −26 Gt a−1, the Antarctic total gain is 95 ± 25 Gt a−1 during 2003–08, compared to 144 ± 61 Gt a−1 from ERS1/2 during 1992–2001. Beginning in 2009, large increases in coastal WA dynamic losses overcame long-term EA and inland WA gains bringing Antarctica close to balance at −12 ± 64 Gt a−1 by 2012–16.

scholarly journals By Slow Degrees: Two Centuries of Social Reproduction and Mobility in Britain

2007 ◽  
Vol 12 (1) ◽  
pp. 37-62 ◽  
Author(s):  
Paul Lambert ◽  
Kenneth Prandy ◽  
Wendy Bottero
Keyword(s):  
Social Mobility ◽  
Social Reproduction ◽  
Linear Trend ◽  
Time Frame ◽  
Quality Of Data ◽  
Term Change ◽  
Parental Background ◽  
Long Term Trends

This paper discusses long term trends in patterns of intergenerational social mobility in Britain. We argue that there is convincing empirical evidence of a small but steady linear trend towards increasing social mobility throughout the period 1800-2004. Our conclusions are based upon the construction and analysis of an extended micro-social dataset, which combines records from an historical genealogical study, with responses from 31 sample surveys conducted over the period 1963-2004. There has been much previous study of trends in social mobility, and little consensus on their nature. We argue that this dissension partly results from the very slow pace of change in mobility rates, which makes the time-frame of any comparison crucial, and raises important methodological questions about how long-term change in mobility is best measured. We highlight three methodological difficulties which arise when trying to draw conclusions over mobility trends - concerning the extent of controls for life course effects; the quality of data resources; and the measurement of stratification positions. After constructing a longitudinal dataset which attempts to confront these difficulties, our analyses provide robust evidence which challenges hitherto more popular, politicised claims of declining or unchanging mobility. By contrast, our findings suggest that Britain has moved, and continues to move, steadily towards increasing equality in the relationship between occupational attainment and parental background.

Sign in / Sign up

Export Citation Format

Share Document