scholarly journals Snow accumulation variability in Adelie Land (East Antarctica) derived from radar and firn core data. A 600 km transect from Dome C

2012 ◽  
Vol 6 (4) ◽  
pp. 2855-2889 ◽  
Author(s):  
D. Verfaillie ◽  
M. Fily ◽  
E. Le Meur ◽  
O. Magand ◽  
B. Jourdain ◽  
...  
Keyword(s):  
Mass Balance ◽  
Austral Summer ◽  
Temporal Variations ◽  
Snow Accumulation ◽  
Data Depth ◽  
East Antarctica ◽  
Spatial And Temporal Variability ◽  
Coastal Station ◽  
International Polar Year ◽  
Polar Ice Sheets

Abstract. Polar ice sheets mass balance is a timely topic intensively studied in the context of global change and sea-level rise. However, obtaining mass balance estimates in Antarctica in particular, remains difficult due to various logistical problems. In the framework of the TASTE-IDEA program, labeled as an International Polar Year project, continuous Ground Penetrating Radar (GPR) measurements were carried out during a traverse realised in Adelie Land (East Antarctica) during the 2008–2009 austral summer between the Italo-French Dome C (DC) polar plateau site and French Dumont D'Urville (DdU) coastal station. The aim of this study was to process and interpret GPR data in terms of snow accumulation, to analyse its spatial and temporal variability along the DC-DdU traverse and compare it with historical data and modeling. The emphasis has been put on the last 300 yr, from the pre-industrial to recent time period. Beta-radioactivity counting and gamma spectrometry were studied in cores at LGGE laboratory, providing a depth-age calibration for radar measurements. Over the 600 km of usable GPR data, depth and snow accumulation were determined with the help of three distinct layers visible on the radargrams (≈1730, 1799 and 1941 AD). Preliminary results reveal a gradual accumulation increase towards the coast and the occurrence of previously undocumented undulating structures between 300 and 600 km from DC. Results agree fairly well with data from previous studies and modeling. Concluding on temporal variations is difficult because of the margin of error introduced by density estimation. This study should have various applications such as for model validation.

scholarly journals Snow accumulation variability derived from radar and firn core data along a 600 km transect in Adelie Land, East Antarctic plateau

2012 ◽  
Vol 6 (6) ◽  
pp. 1345-1358 ◽  
Author(s):  
D. Verfaillie ◽  
M. Fily ◽  
E. Le Meur ◽  
O. Magand ◽  
B. Jourdain ◽  
...  
Keyword(s):  
Mass Balance ◽  
Austral Summer ◽  
Temporal Variations ◽  
Snow Accumulation ◽  
Data Depth ◽  
East Antarctica ◽  
Spatial And Temporal Variability ◽  
Coastal Station ◽  
International Polar Year ◽  
Ground Penetrating

Abstract. The mass balance of ice sheets is an intensively studied topic in the context of global change and sea-level rise. However – particularly in Antarctica – obtaining mass balance estimates remains difficult due to various logistical problems. In the framework of the TASTE-IDEA (Trans-Antarctic Scientific Traverses Expeditions – Ice Divide of East Antarctica) program, an International Polar Year project, continuous ground penetrating radar (GPR) measurements were carried out during a traverse in Adelie Land (East Antarctica) during the 2008–2009 austral summer between the Italian–French Dome C (DC) polar plateau site and French Dumont D'Urville (DdU) coastal station. The aim of this study was to process and interpret GPR data in terms of snow accumulation, to analyse its spatial and temporal variability and compare it with historical data and modelling. The focus was on the last 300 yr, from the pre-industrial period to recent times. Beta-radioactivity counting and gamma spectrometry were applied to cores at the LGGE laboratory, providing a depth–age calibration for radar measurements. Over the 600 km of usable GPR data, depth and snow accumulation were determined with the help of three distinct layers visible on the radargrams (≈ 1730, 1799 and 1941 AD). Preliminary results reveal a gradual increase in accumulation towards the coast (from ≈ 3 cm w.e. a−1 at Dome C to ≈ 17 cm w.e. a−1 at the end of the transect) and previously undocumented undulating structures between 300 and 600 km from DC. Results agree fairly well with data from previous studies and modelling. Drawing final conclusions on temporal variations is difficult because of the margin of error introduced by density estimation. This study should have various applications, including model validation.

scholarly journals Temporal and spatial variability of surface mass balance at Dome Fuji, East Antarctica, by the stake method from 1995 to 2006

2008 ◽  
Vol 54 (184) ◽  
pp. 107-116 ◽  
Author(s):  
Takao Kameda ◽  
Hideaki Motoyama ◽  
Shuji Fujita ◽  
Shuhei Takahashi
Keyword(s):  
Mass Balance ◽  
Ice Core ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Frequency Distributions ◽  
Temporal And Spatial Variability ◽  
The Antarctic ◽  
Height Data

AbstractThe surface mass balance (SMB) at Dome Fuji, East Antarctica, was estimated using 36 bamboo stakes (grid of 6 × 6, placed at 20 m intervals) from 1995 to 2006. The heights of the stake tops from the snow surface were measured at 0.5 cm resolution twice monthly in 1995, 1996, 1997 and 2003, and once a year for the rest of the study period. To account for snow settling, the average snow density at the stake base during the measurements was used for converting the stake-height data to SMB. The annual SMB from 1995 to 2006 at Dome Fuji was 27.3 ± 1.5 kg m−2 a−1. This result agrees well with the annual SMB from AD 1260 to 1993 (26.4 kg m−2 a−1) estimated from volcanic signals in the Dome Fuji ice core. Over the period 1995–2006, there were 37 (8.6% of the measurements) negative or zero annual SMB results. Variation in the multi-year averages of annual SMB decreased with the square root of the number of observation years, and 10 years of observations of a single stake allowed the estimation of annual SMB at ±10% accuracy. The frequency distributions of annual and monthly SMB were examined. The findings clarify the complex behavior of the annual and monthly SMB at Dome Fuji, which will be common phenomena in areas of low snow accumulation of the interior of the Antarctic ice sheet.

scholarly journals Features of meteorological events preserved in a high-resolution Law Dome (East Antarctica) snow pit

2002 ◽  
Vol 35 ◽  
pp. 463-470 ◽  
Author(s):  
Alison J. McMorrow ◽  
Mark A. J. Curran ◽  
Tas D. Van Ommen ◽  
Vin I. Morgan ◽  
Ian Allison
Keyword(s):  
High Resolution ◽  
Austral Summer ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Synoptic Scale ◽  
High Accumulation ◽  
Oxygen Isotope Ratios ◽  
Source Regions ◽  
Ion Species ◽  
Very High

AbstractSnow-pit and shallow firn-core records of oxygen isotope ratios (δ18O) and trace ion species were generated at a high-accumulation site on Law Dome, East Antarctica. Concordance between accumulation events identified in records up to 7.7 km a part confirms that the observed glaciochemical variations are the result of regional rather than local surface effects. This allows calibration of the snow-pit records with measured meteorological parameters. Net accumulation periods that comprise the snow-pit record are identified using hourly snow-accumulation measurements from a co-located automatic weather station (AWS). Particular focus is given to three net accumulation periods preserved during austral summer 1999/2000 that correspond to the top 0.5 m of the snow pit. Local meteorological conditions recorded during the summer accumulation periods by the AWS are combined with regional and synoptic-scale meteorology derived from Casey station (110 km away) and Advanced Very High Resolution Radiometer satellite imagery to identify potential source regions for chemical signals preserved in summer snow at Law Dome.

scholarly journals Snow Stratigraphic Studies At Dome C, East Antarctica: An Investigation Of Depositional and Diagenetic Processes

1982 ◽  
Vol 3 ◽  
pp. 239-242 ◽  
Author(s):  
J. M. Palais ◽  
I. M. Whillans ◽  
C. Bull
Keyword(s):  
Ice Sheets ◽  
Ice Cores ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Polar Ice ◽  
Depositional Processes ◽  
Diagenetic Processes ◽  
Snow Stratigraphy ◽  
Stratigraphic Record ◽  
Polar Ice Sheets

The increased interest in past climatic changes, as revealed by studies of long ice cores from polar ice sheets, has stressed the need for a better understanding of the development of the stratigraphic record preserved in these cores. This paper presents some results of surface investigations at Dome C (74°30'S, 123°10'E), East Antarctica, carried out in austral summers 1978-79 and 1979-80. An explanation is presented of the snow stratigraphy, in terms of depositional and post-depositional processes, that is supported by detailed accumulation measurements at stakes and by snow-pit studies. Temporal and areal variability of snow accumulation are investigated to determine how representative the results interpreted from a single core might be for the Dome C region. Finally, the reliability of several stratigraphic methods for defining annual layers is assessed.Snow-pit studies show that major depositional features are preserved with depth. Visible annual strata at Dome C are composed of thin, hard crusts overlying thicker layers of soft to medium-hard snow. Low density depth-hoar layers, when they occur, are usually found below the thin, hard crusts. Depth profiles of gross 8-radioactivity and of microparticles concentration exhibit annual cyclicity which, together with the detailed visible stratigraphy, can be used to assign dates to the layers.

scholarly journals Ice flux of Plogbreen, a small ice stream in Dronning Maud Land, Antarctica

2004 ◽  
Vol 39 ◽  
pp. 409-416
Author(s):  
Jim Hedfors ◽  
Veijo Allan Pohjola
Keyword(s):  
Mass Balance ◽  
Ice Core ◽  
Austral Summer ◽  
Snow Accumulation ◽  
Surface Velocity ◽  
Cross Sectional ◽  
Ice Surface ◽  
Dronning Maud Land ◽  
Using Data

AbstractAs part of a long-term mass-balance program run by SWEDARP since 1988, a detailed study on Plogbreen, Dronning Maud Land, Antarctica, was undertaken during the austral summer of 2003 to investigate the long-term mass balance. We compare ice outflux, φout, through a cross-sectional gate with ice influx, φin, from the upstream catchment area. The φin is based on calculations of snow accumulation upstream of the gate using data available from published ice-core records. The φout is based on Glen’s flow law aided by thermodynamic modeling and force-budget calculations. Input data from the field consist of measurements of ice surface velocity and ice geometry. The ice surface velocity was measured using repeated differential global positioning system surveying of 40 stakes over a period of 25 days. The ice geometry was determined by 174 km of ground-penetrating radar profiling using ground-based 8MHz dipole antennas. This study presents the collected velocity and geometry data as well as the calculated ice flux of Plogbreen. The results show a negatively balanced system within the uncertainty limits; φout = 0.55 ± 0.05 km3 a–1 and φin = 0.4 ± 0.1 km3 a–1. We speculate that the negative balance can be explained by recent eustatic increase reducing resistive stresses and inducing accelerated flow.

scholarly journals Spatial variability of surface mass balance along a traverse route from Zhongshan station to Dome A, Antarctica

2011 ◽  
Vol 57 (204) ◽  
pp. 658-666 ◽  
Author(s):  
Ding Minghu ◽  
Xiao Cunde ◽  
Li Yuansheng ◽  
Ren Jiawen ◽  
Hou Shugui ◽  
...  
Keyword(s):  
Mass Balance ◽  
Temporal Change ◽  
Accumulation Rate ◽  
Austral Summer ◽  
Snow Accumulation ◽  
Surface Mass Balance ◽  
Dome A ◽  
Surface Mass ◽  
Zhongshan Station ◽  
Meteorological Features

AbstractStakes at 2 km intervals were installed in January 1997 and remeasured in February 1998, January 1999, January 2005 and during the 2007/08 austral summer along a 1248 km traverse route from Zhongshan station to Dome A, East Antarctica. Based on topographical parameters, meteorological features and the records of ∼650 stakes and six stake arrays, the route is divided into five zones. We find that the snow accumulation rate decreases with increasing altitude as one progresses inland, except in the zone 800–1128 km from the coast, where the average annual accumulation rate is higher than in the zone 524–800 km from the coast. The Dome A zone (1128–1248 km) has the lowest accumulation rate (35 kg m−2 a−1, 2005–08) due to having the highest elevation and being furthest from the coast. The surface mass balance in the region 202–1128 km from the coast exhibits no temporal change from 1999–2005 to 2005–08, but there is a change in the accumulation distribution. The zone from 202 to 524 km shows a decrease in surface mass balance from 84 kg m−2 a−1 in 1999–2005 to 67 kg m−2 a−1 in 2005–08, while the zone between 800 and 1128 km shows an increase from 67 kg m−2 a−1 in 1999–2005 to 75 kg m−2 a−1 in 2005–08.

scholarly journals Snow Stratigraphic Studies At Dome C, East Antarctica: An Investigation Of Depositional and Diagenetic Processes

1982 ◽  
Vol 3 ◽  
pp. 239-242 ◽  
Author(s):  
J. M. Palais ◽  
I. M. Whillans ◽  
C. Bull
Keyword(s):  
Ice Sheets ◽  
Ice Cores ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Polar Ice ◽  
Depositional Processes ◽  
Diagenetic Processes ◽  
Snow Stratigraphy ◽  
Stratigraphic Record ◽  
Polar Ice Sheets

The increased interest in past climatic changes, as revealed by studies of long ice cores from polar ice sheets, has stressed the need for a better understanding of the development of the stratigraphic record preserved in these cores. This paper presents some results of surface investigations at Dome C (74°30'S, 123°10'E), East Antarctica, carried out in austral summers 1978-79 and 1979-80. An explanation is presented of the snow stratigraphy, in terms of depositional and post-depositional processes, that is supported by detailed accumulation measurements at stakes and by snow-pit studies. Temporal and areal variability of snow accumulation are investigated to determine how representative the results interpreted from a single core might be for the Dome C region. Finally, the reliability of several stratigraphic methods for defining annual layers is assessed. Snow-pit studies show that major depositional features are preserved with depth. Visible annual strata at Dome C are composed of thin, hard crusts overlying thicker layers of soft to medium-hard snow. Low density depth-hoar layers, when they occur, are usually found below the thin, hard crusts. Depth profiles of gross 8-radioactivity and of microparticles concentration exhibit annual cyclicity which, together with the detailed visible stratigraphy, can be used to assign dates to the layers.

scholarly journals Ground-based measurements of spatial and temporal variability of snow accumulation in East Antarctica

2008 ◽  
Vol 46 (2) ◽  
Author(s):  
Olaf Eisen ◽  
Massimo Frezzotti ◽  
Christophe Genthon ◽  
Elisabeth Isaksson ◽  
Olivier Magand ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Spatial And Temporal Variability

scholarly journals A 14 year mass-balance record of a blue-ice area in Antarctica

2003 ◽  
Vol 37 ◽  
pp. 213-218 ◽  
Author(s):  
Anna Sinisalo ◽  
John C. Moore ◽  
Roderik S.W. Van De Wal ◽  
Richard Bintanja ◽  
Stig Jonsson
Keyword(s):  
Mass Balance ◽  
Transition Zone ◽  
Confidence Level ◽  
Accumulation Rate ◽  
Ablation Rate ◽  
Temporal Variations ◽  
Snow Accumulation ◽  
Entire Period ◽  
Spatial And Temporal Variations ◽  
Clear Trend

AbstractAccumulation and ablation rates over an Antarctic blue-ice area spanning the 14year period 1988–2002 are presented. Data were obtained by direct stake measurements. Large spatial and temporal variations in the net balance were observed without any clear trend over the entire period. There are marginally significant increases in snow accumulation, and in ablation in the blue-ice area farthest from the equilibrium zone (both at the 95% confidence level). The snow/blue-ice transition zone shows no change over the entire period of observation,and the blue-ice area near the zone shows no change in ablation rate over the 14 year period. The mass-balance gradient in Scharffenbergbotnen may have increased during the period 1988–2002. However, the changes are small, especially when compared with the changes observed elsewhere in Antarctica even relatively close to the blue-ice area. This may indicate that the blue-ice areas are relatively stable to changes in accumulation rate, and possibly temperature.

scholarly journals A snow sensor experiment in Dronning Maud Land, Antarctica

2009 ◽  
Vol 55 (194) ◽  
pp. 1041-1051 ◽  
Author(s):  
Hardy B. Granberg ◽  
Patrick Cliche ◽  
Olli-Pekka Mattila ◽  
Eija Kanto ◽  
Matti Leppäranta
Keyword(s):  
Mass Balance ◽  
Data Transfer ◽  
Potential Temperature ◽  
Ice Sheet ◽  
Temporal Variations ◽  
Snow Accumulation ◽  
Research Station ◽  
Shelf Edge ◽  
Katabatic Winds ◽  
Dronning Maud Land

AbstractIn January 2000 nine snow sensors were deployed in Dronning Maud Land, Antarctica, along a 355 km transect from Kvitkuven near the shelf edge via the Finnish research station, Aboa, to the Amundsenisen plateau. The purpose was to test a sensor system for spatio-temporal variations in temperature across the snow–air interface and snow accumulation/ablation, which includes atmospheric net balance and migrating snow dunes. In the dry snow conditions, environmental static electricity interfered with data transfer; several sensors were disabled early, while the longest record reached 6 months. Along the main transect, the year 2000 mass balance ranged from 52 to 221 mm w.e., largely following spatial patterns seen by other researchers. The level increased toward the edge of the ice sheet; unloading of drifting snow as the slope flattens, rather than increased snowfall as previously thought, may be responsible for this. At the Högisen ice dome site the mass balance was 897 mm w.e., possibly due to unloading of wind-blown snow, as katabatic winds are locally forced uphill. This mechanism is important to maintain such topographic features along the Antarctic ice sheet margin. Major precipitation events occurred at 3–5 week intervals and much of the precipitation fell before mid-June. The daily signal in temperature disappeared after the autumn equinox, then the spectrum displayed a broad peak at synoptic frequencies. Potential temperature decreased towards the shelf edge, displaying a pattern consistent with strong inversions and suggesting that strong evaporative cooling is associated with the katabatic winds.

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