scholarly journals Spatial variability of snow chemistry in western Dronning Maud Land, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 378-384 ◽  
Author(s):  
Malin Stenbrrg ◽  
Elisabeth Isaksson ◽  
Margareta Hansson ◽  
WibjöRn Karlen ◽  
Paul A. Mayewski ◽  
...  
Keyword(s):  
High Altitude ◽  
Accumulation Rate ◽  
Austral Summer ◽  
Sea Salt ◽  
Stable Oxygen Isotopes ◽  
Methane Sulfonate ◽  
Snow Chemistry ◽  
Range Transport ◽  
Dronning Maud Land ◽  
Stable Oxygen

During the austral summer of 1993-94 a number of 1-2 m deep snow pits were sampled in connection with firn-coring in western Dronning Maud Land, Antarctica. The traverse went from 800 to about 3000 m a.s.l. upon the high-altitude plateau. Profiles of cations (Na+, K+, Mg2+, Ca2+), anions (Cl−, NO3-, SO4 2- , CH3SO3 −) and stable oxygen isotopes (δ18O) from 11 snow pils are presented here. Close to the coast 2 m of snow accumulates in about 2-3 years, whilst at sites on the high-altitude plateau 2 m of snow accumulates in 10—14 years. The spatial variation in ion concentrations shows that the ions can be divided into two groups, one with sea-salt elements and methane sulfonate and the other with nitrate and sulfate. For the sca-salt elements and methane sulfonate the concentrations decrease with increasing altitude and increasing distance from the coast, as well as with decreasing temperature and decreasing accumulation rate. For nitrate and sulfate the concentrations are constant or increase with respect to these parameters. This pattern suggests that the sources for sca-salt elements and methane sulfonate are local, whereas the sources for nitrate and sulfate are a mixture of local and long-range transport.

scholarly journals Large spatial variation in accumulation rate in Jutulstraumen ice stream, Dronning Maud Land, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 231-238 ◽  
Author(s):  
Kjetil Melvold ◽  
Jon Ove Hagen ◽  
Jean Francis Pinglot ◽  
Niels Gunuestrup
Keyword(s):  
Mass Balance ◽  
Accumulation Rate ◽  
Austral Summer ◽  
Katabatic Winds ◽  
Surface Gradient ◽  
Ice Stream ◽  
Dronning Maud Land ◽  
Temporal And Spatial ◽  
Accumulation Trend ◽  
Local Accumulation

A mass-balance programme was initiated on Jutulstraumen ice stream, western Dronning Maud Land,Antarctica, during the austral summer 1992-93. As a part of the mass-balance programme, accumulation rate was measured along the centre line of Jutulstraumen from the shelf edge up to the plateau at about 2500 m a.s.l. Accumulation distribution obtained from seven shallow firn cores and 48 slake readings is presented. The overall net accumulation trend displays a decreasing accumulation with increasing elevation and distance to coast, but on both the mesoscale and microscale there are significant variations. This is due to complex patterns of precipitation controlled by orography and redistribution by katabatic winds. The local accumulation distribution (few km scale) was found to be dependent on downslope surface gradient (aspect north, northwest), and variations up to 100% were found over distances of less than 3 km. The large variation in accumulation is important when selecting new core sites and for interpretation of temporal and spatial variations in accumulation derived from firn cores.

scholarly journals Accumulation variability derived from an ice core from coastal Dronning Maud Land, Antarctica

2004 ◽  
Vol 39 ◽  
pp. 339-345 ◽  
Author(s):  
Marzena Kaczmarska ◽  
Elisabeth Isaksson ◽  
Lars Karlöf ◽  
Jan-Gunnar Winther ◽  
Jack Kohler ◽  
...  
Keyword(s):  
High Resolution ◽  
Accumulation Rate ◽  
Ice Core ◽  
Austral Summer ◽  
Conductivity Measurement ◽  
Ice Cores ◽  
Electrical Conductivity Measurement ◽  
Regional Pattern ◽  
Dronning Maud Land

AbstractA 100 m long ice core was retrieved from the coastal area of Dronning Maud Land (DML), Antarctica, in the 2000/01 austral summer. The core was dated to AD 1737 by identification of volcanic horizons in dielectrical profiling and electrical conductivity measurement records in combination with seasonal layer counting from high-resolution oxygen isotope (δ18O) data. A mean long-term accumulation rate of 0.29 ma–1w.e. was derived from the high-resolution δ18O record as well as accumulation rates during periods in between the identified volcanic horizons. A statistically significant decrease in accumulation was found from about 1920 to the present. A comparison with other coastal ice cores from DML suggests that this is a regional pattern.

scholarly journals A high-altitude snow chemistry record from Amundsenisen, Dronning Maud Land, Antarctica

2001 ◽  
Vol 47 (158) ◽  
pp. 489-496 ◽  
Author(s):  
Elisabeth Isaksson ◽  
Wibjörn Karlén ◽  
Paul Mayewski ◽  
Mark Twickler ◽  
Sallie Whitlow
Keyword(s):  
New Zealand ◽  
High Altitude ◽  
Major Ions ◽  
Southern Oscillation ◽  
Austral Summer ◽  
Volcanic Eruptions ◽  
The Core ◽  
Dronning Maud Land ◽  
South Shetlands ◽  
The Antarctic

AbstractIn this paper a detailed record of major ions from a 20 m deep firn core from Amundsenisen, western Dronning Maud Land, Antarctica, is presented. The core was drilled at 75° S, 2° E (2900 m a.s.l.) during austral summer 1991/92. The following ions were measured at 3 cm resolution: Na+, Mg2+, Ca2+, Cl−, NO3−, S042− and CH3SO3H (MSA). The core was dated back to 1865 using a combination of chemical records and volcanic reference horizons. The volcanic eruptions identified in this core are Mount Ngauruhoe, New Zealand (1974–75), Mount Agung, Indonesia (1963), Azul, Argentina (1932), and a broad peak that corresponds in time toTarawera, New Zealand (1886), Falcon Island, South Shetlands, Southern Ocean (1885), and Krakatau, Indonesia (1883). There are no trends in any of the ion records, but the annual to decadal changes are large. The mean concentrations of the measured ions are in agreement with those from other high-altitude cores from the Antarctic plateau. At this core site there may be a correspondence between peaks in the MSA record and major El Niño–Southern Oscillation events.

scholarly journals A 485 year record of atmospheric chloride, nitrate and sulfate: results of chemical analysis of ice cores from Dyer Plateau, Antarctic Peninsula

1995 ◽  
Vol 21 ◽  
pp. 182-188 ◽  
Author(s):  
Jihong Cole Dai ◽  
Lonnie G. Thompson ◽  
Ellen Mosley-Thompson
Keyword(s):  
Sea Water ◽  
Accumulation Rate ◽  
Linear Regression Analysis ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Sea Salt ◽  
Volcanic Emissions ◽  
Data Set ◽  
Snow Chemistry

Detailed ionic analyses of Dyer Plateau snow show that major soluble impurities in snow consist of sodium (Na+), chloride (Cl−), nitrate (NO3−), sulfate (SO42−), and acidity (H+). The ratios of Na+ to Cl− concentrations are close to that of sea water, indicating little or no fractionation of sea-salt aerosols. The analyses of core sections from three sites along a 10 km transect show that local spatial variation of snow chemistry in this area is minimal and that temporal (decadal, inter-annual and sub-annual) variations in snow chemistry are very well preserved.Anion analyses of the upper 181 m section of two 235 m ice cores yield a data set of 485 years (1505-1989) of annual snow accumulation and fluxes of Cl−, NO3−, and non-sea-salt (nss) SO42−. No significant long-term trends are observed in any of the anion fluxes. This is consistent with other Antarctic ice-core records showing no significant anthropogenic atmospheric pollution in the high southern latitudes. Linear regression analysis shows that Cl− flux is independent of snow-accumulation rate. Significant positive correlations are found between accumulation rate and both NO3− flux and background nss-SO42− flux. These results suggest that dry deposition is primarily responsible for air-to-ground Cl− flux while wet deposition dominates the NO3− and nss-SO42− flux (≥90% and ≥75%, respectively). The nss-S042− fluxes provide a chronology of explosive volcanic emissions reaching the Antarctic region for the past 485 years.

scholarly journals Snow-accumulation studies in Antarctica with ground-penetrating radar using 50, 100 and 800 MHz antenna frequencies

2003 ◽  
Vol 37 ◽  
pp. 194-198 ◽  
Author(s):  
Anna Sinisalo ◽  
Aslak Grinsted ◽  
John C. Moore ◽  
Eija Kärkäs ◽  
Rickard Pettersson
Keyword(s):  
Accumulation Rate ◽  
Austral Summer ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Research Station ◽  
Dronning Maud Land ◽  
The Individual ◽  
Ground Penetrating ◽  
Radar Antenna ◽  
Radar Wave

AbstractSnow radar profiles were measured in Dronning Maud Land, East Antarctica, in the vicinity of the Finnish research station Aboa during austral summer 1999/2000. The aim was to study the annual layering in the upper 50 m of the snowpack and to compare the results obtained by three radar antenna frequencies (50, 100 and 800 MHz). Intercomparison of the radar profiles measured by the three frequencies shows that some individua linternal layers are visible with different antennas. Sparse accumulation-rate data from stake measurements and snow pits are compared with layer depths. The comparison reveals a great deal of scatter due to the large interannual variability in accumulation patterns. Using the radar layers as isochrones together with a model of depth–density–radar-wave velocity allows the individual accumulation data to be integrated, and a better estimate of accumulation patterns is obtained. Using the radar layering seems to be a much better method of estimating accumulation rate in this region than using a short series of stake measurements, even in the absence of deep ice cores to directly date the radar layering.

scholarly journals A 485 year record of atmospheric chloride, nitrate and sulfate: results of chemical analysis of ice cores from Dyer Plateau, Antarctic Peninsula

1995 ◽  
Vol 21 ◽  
pp. 182-188 ◽  
Author(s):  
Jihong Cole Dai ◽  
Lonnie G. Thompson ◽  
Ellen Mosley-Thompson
Keyword(s):  
Sea Water ◽  
Accumulation Rate ◽  
Linear Regression Analysis ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Sea Salt ◽  
Volcanic Emissions ◽  
Data Set ◽  
Snow Chemistry

Detailed ionic analyses of Dyer Plateau snow show that major soluble impurities in snow consist of sodium (Na+), chloride (Cl−), nitrate (NO3 −), sulfate (SO4 2−), and acidity (H+). The ratios of Na+ to Cl− concentrations are close to that of sea water, indicating little or no fractionation of sea-salt aerosols. The analyses of core sections from three sites along a 10 km transect show that local spatial variation of snow chemistry in this area is minimal and that temporal (decadal, inter-annual and sub-annual) variations in snow chemistry are very well preserved. Anion analyses of the upper 181 m section of two 235 m ice cores yield a data set of 485 years (1505-1989) of annual snow accumulation and fluxes of Cl−, NO3 −, and non-sea-salt (nss) SO4 2−. No significant long-term trends are observed in any of the anion fluxes. This is consistent with other Antarctic ice-core records showing no significant anthropogenic atmospheric pollution in the high southern latitudes. Linear regression analysis shows that Cl− flux is independent of snow-accumulation rate. Significant positive correlations are found between accumulation rate and both NO3 − flux and background nss-SO4 2− flux. These results suggest that dry deposition is primarily responsible for air-to-ground Cl− flux while wet deposition dominates the NO3 − and nss-SO4 2− flux (≥90% and ≥75%, respectively). The nss-S04 2− fluxes provide a chronology of explosive volcanic emissions reaching the Antarctic region for the past 485 years.

scholarly journals Stable oxygen isotopes in shallow marine ostracodes from the northern Bering and Chukchi Seas

2021 ◽  
pp. 101979
Author(s):  
L. Gemery ◽  
L.W. Cooper ◽  
C. Magen ◽  
T.M. Cronin ◽  
J.M. Grebmeier
Keyword(s):  
Oxygen Isotopes ◽  
Stable Oxygen Isotopes ◽  
Shallow Marine ◽  
Stable Oxygen

scholarly journals Small-scale spatio-temporal characteristics of accumulation rates in western Dronning Maud Land, Antarctica

2008 ◽  
Vol 54 (185) ◽  
pp. 315-323 ◽  
Author(s):  
Helgard Anschütz ◽  
Daniel Steinhage ◽  
Olaf Eisen ◽  
Hans Oerter ◽  
Martin Horwath ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Temporal Variations ◽  
Spatial Variations ◽  
Small Scale ◽  
Accumulation Rates ◽  
Order Of Magnitude ◽  
Dronning Maud Land ◽  
Spatio Temporal ◽  
Ground Penetrating ◽  
Firn Core

AbstractSpatio-temporal variations of the recently determined accumulation rate are investigated using ground-penetrating radar (GPR) measurements and firn-core studies. The study area is located on Ritscherflya in western Dronning Maud Land, Antarctica, at an elevation range 1400–1560 m. Accumulation rates are derived from internal reflection horizons (IRHs), tracked with GPR, which are connected to a dated firn core. GPR-derived internal layer depths show small relief along a 22 km profile on an ice flowline. Average accumulation rates are about 190 kg m−2 a−1 (1980–2005) with spatial variability (1σ) of 5% along the GPR profile. The interannual variability obtained from four dated firn cores is one order of magnitude higher, showing 1σ standard deviations around 30%. Mean temporal variations of GPRderived accumulation rates are of the same magnitude or even higher than spatial variations. Temporal differences between 1980–90 and 1990–2005, obtained from two dated IRHs along the GPR profile, indicate temporally non-stationary processes, linked to spatial variations. Comparison with similarly obtained accumulation data from another coastal area in central Dronning Maud Land confirms this observation. Our results contribute to understanding spatio-temporal variations of the accumulation processes, necessary for the validation of satellite data (e.g. altimetry studies and gravity missions such as Gravity Recovery and Climate Experiment (GRACE)).

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