scholarly journals Climate since AD 1510 on Dyer Plateau, Antarctic Peninsula: evidence for recent climate change

1994 ◽  
Vol 20 ◽  
pp. 420-426 ◽  
Author(s):  
L. G. Thompson ◽  
D. A. Peel ◽  
E. Mosley-thompson ◽  
R. Mulvaney ◽  
J. Dal ◽  
...  
Keyword(s):  
19Th Century ◽  
Antarctic Peninsula ◽  
Chemical Species ◽  
Ice Cores ◽  
Warming Trend ◽  
Snow Accumulation ◽  
Annual Variations ◽  
Recent Climate ◽  
The 19Th Century ◽  
The Antarctic

A 480 year record of the oxygen-isotope ratios, dust content, chemical species and net accumulation from ice cores drilled in 1989 90 on Dyer Plateau in the Antarctic Peninsula is presented. The continuous analyses of small (sub-annual) samples reveal well-preserved annual variations in both sulfate content and δ18O, thus allowing an excellent time-scale to be established.This history reveals a recent pronounced warming in which the last two decades have been among the warmest in the last five centuries. Furthermore, unlike in East Antarctica, on Dyer Plateau conditions appear to have been fairly normal from AD 1500 to 1850 with cooler conditions from 1850 to 1930 and a warming trend dominating since 1930. Reconstructed annual layer thicknesses suggest an increase in net accumulation beginning early in the 19th century and continuing to the present. This intuitive conflict between increasing net accumulation and depleted δ18O (cooler climate) in the 19th century appears widespread in the peninsula region and challenges our understanding of the physical relationships among moisture sources, air temperatures and snow accumulation. The complex meteorological regime in the Antarctic Peninsula region complicates meaningful interpretation of proxy indicators and results in a strong imprint of local high-frequency processes upon the larger-scale climate picture.

scholarly journals Climate since AD 1510 on Dyer Plateau, Antarctic Peninsula: evidence for recent climate change

1994 ◽  
Vol 20 ◽  
pp. 420-426 ◽  
Author(s):  
L. G. Thompson ◽  
D. A. Peel ◽  
E. Mosley-thompson ◽  
R. Mulvaney ◽  
J. Dal ◽  
...  
Keyword(s):  
19Th Century ◽  
Antarctic Peninsula ◽  
Chemical Species ◽  
Ice Cores ◽  
Warming Trend ◽  
Snow Accumulation ◽  
Annual Variations ◽  
Recent Climate ◽  
The 19Th Century ◽  
The Antarctic

A 480 year record of the oxygen-isotope ratios, dust content, chemical species and net accumulation from ice cores drilled in 1989 90 on Dyer Plateau in the Antarctic Peninsula is presented. The continuous analyses of small (sub-annual) samples reveal well-preserved annual variations in both sulfate content and δ18O, thus allowing an excellent time-scale to be established.This history reveals a recent pronounced warming in which the last two decades have been among the warmest in the last five centuries. Furthermore, unlike in East Antarctica, on Dyer Plateau conditions appear to have been fairly normal from AD 1500 to 1850 with cooler conditions from 1850 to 1930 and a warming trend dominating since 1930. Reconstructed annual layer thicknesses suggest an increase in net accumulation beginning early in the 19th century and continuing to the present. This intuitive conflict between increasing net accumulation and depleted δ18O (cooler climate) in the 19th century appears widespread in the peninsula region and challenges our understanding of the physical relationships among moisture sources, air temperatures and snow accumulation. The complex meteorological regime in the Antarctic Peninsula region complicates meaningful interpretation of proxy indicators and results in a strong imprint of local high-frequency processes upon the larger-scale climate picture.

scholarly journals Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past-temperature reconstructions

2015 ◽  
Vol 9 (4) ◽  
pp. 1481-1504 ◽  
Author(s):  
V. Masson-Delmotte ◽  
H. C. Steen-Larsen ◽  
P. Ortega ◽  
D. Swingedouw ◽  
T. Popp ◽  
...  
Keyword(s):  
19Th Century ◽  
North Atlantic ◽  
Accumulation Rate ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Last Interglacial ◽  
Bottom Part ◽  
Recent Climate ◽  
Temperature Reconstructions

Abstract. Combined records of snow accumulation rate, δ18O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (North Greenland Eemian Ice Drilling), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterise the isotope–temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ18O and accumulation variability is related to North Atlantic sea surface temperature and is enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ18O shows multidecadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ18O values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ18O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815–1825 and 1836–1846, which are also the driest 11-year periods. The NEEM accumulation and δ18O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multidecadal accumulation–temperature and δ18O–temperature relationships for the strong warming period in 1979–2007. The accumulation sensitivity to temperature is estimated at 11 ± 2 % °C−1 and the δ18O–temperature slope at 1.1 ± 0.2 ‰ °C−1, about twice as large as previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core.

scholarly journals Air Temperature and Snow Accumulation in the Antarctic Peninsula During the Past 50 Years (Abstract)

1988 ◽  
Vol 11 ◽  
pp. 207-207 ◽  
Author(s):  
David A. Peel ◽  
Robert Mulvaney
Keyword(s):  
Antarctic Peninsula ◽  
Accumulation Rate ◽  
Ice Sheet ◽  
Ice Cores ◽  
Snow Accumulation ◽  
The West ◽  
Climate Type ◽  
The Past ◽  
The Antarctic ◽  
Noise Factors

Trends in climate affecting the West Antarctic ice sheet may be detected first in the Antarctic Peninsula region. Although the area contains the most comprehensive weather records for any part of Antarctica, reliable snow-accumulation data are lacking.Mainly as a result of the large snow-accumulation rate in the region (typically in the range 4.0–10.0 kg m−2 a−1), stratigraphie evidence of climate derived from ice cores can be resolved in much greater detail than is possible over most of the continent. Ice cores have been drilled at two sites, representing the extremes of climate type encountered in the region. A 133 m core has been obtained from Dolleman Island (70°35.2′S, 60°55.5′W) to represent the continental-type climate of the Weddell coast region, and an 87 m core has been obtained from the Palmer Land plateau (74°01′S, 70°38′W) to represent the more maritime regime of the west coast and central areas. Replicated cores were obtained at both sites in order to assess the contribution of local noise factors to the climatic signal preserved in the cores. Climatic trends during the period 1938–86 have been assessed on the basis of stable-isotope analysis of the top 47 m of the Palmer Land core and of the top 32 m of the Dolleman Island core.A statistical analysis of derived profiles of mean annual δ18O and accumulation rate indicates that the local noise factors at these sites are sufficiently small that data averaged over periods as short as 5 years should reveal climatic shifts at the level of 0.2% and 5% respectively. These changes are much smaller than trends that have actually occurred during the past 50 years.The most notable trend over the past 30 years is an increase of more than 30% in the snow-accumulation rate that has occurred in parallel with an overall temperature increase of 0.06°C/a during the same period. Increases of similar magnitude can be inferred from studies in East Antarctica, and may be related to a significant increase in precipitation rate that has been documented recently at mid-to high-latitude stations in the Northern Hemisphere. The finding may have relevance to studies of the possible consequences of a CO2-induced climate change. More extensive accumulation time series are now required from Antarctica, if satisfactory models of the long-term balance of the ice sheet are to be derived.

scholarly journals Air Temperature and Snow Accumulation in the Antarctic Peninsula During the Past 50 Years (Abstract)

1988 ◽  
Vol 11 ◽  
pp. 207 ◽  
Author(s):  
David A. Peel ◽  
Robert Mulvaney
Keyword(s):  
Antarctic Peninsula ◽  
Accumulation Rate ◽  
Ice Sheet ◽  
Ice Cores ◽  
Snow Accumulation ◽  
The West ◽  
Climate Type ◽  
The Past ◽  
The Antarctic ◽  
Noise Factors

Trends in climate affecting the West Antarctic ice sheet may be detected first in the Antarctic Peninsula region. Although the area contains the most comprehensive weather records for any part of Antarctica, reliable snow-accumulation data are lacking. Mainly as a result of the large snow-accumulation rate in the region (typically in the range 4.0–10.0 kg m−2 a−1), stratigraphie evidence of climate derived from ice cores can be resolved in much greater detail than is possible over most of the continent. Ice cores have been drilled at two sites, representing the extremes of climate type encountered in the region. A 133 m core has been obtained from Dolleman Island (70°35.2′S, 60°55.5′W) to represent the continental-type climate of the Weddell coast region, and an 87 m core has been obtained from the Palmer Land plateau (74°01′S, 70°38′W) to represent the more maritime regime of the west coast and central areas. Replicated cores were obtained at both sites in order to assess the contribution of local noise factors to the climatic signal preserved in the cores. Climatic trends during the period 1938–86 have been assessed on the basis of stable-isotope analysis of the top 47 m of the Palmer Land core and of the top 32 m of the Dolleman Island core. A statistical analysis of derived profiles of mean annual δ18O and accumulation rate indicates that the local noise factors at these sites are sufficiently small that data averaged over periods as short as 5 years should reveal climatic shifts at the level of 0.2% and 5% respectively. These changes are much smaller than trends that have actually occurred during the past 50 years. The most notable trend over the past 30 years is an increase of more than 30% in the snow-accumulation rate that has occurred in parallel with an overall temperature increase of 0.06°C/a during the same period. Increases of similar magnitude can be inferred from studies in East Antarctica, and may be related to a significant increase in precipitation rate that has been documented recently at mid-to high-latitude stations in the Northern Hemisphere. The finding may have relevance to studies of the possible consequences of a CO2-induced climate change. More extensive accumulation time series are now required from Antarctica, if satisfactory models of the long-term balance of the ice sheet are to be derived.

scholarly journals Evidence of recent climatic warming on the eastern Antarctic Peninsula

1998 ◽  
Vol 27 ◽  
pp. 628-632 ◽  
Author(s):  
Pedro Skvarca ◽  
Wolfgang Rack ◽  
Helmut Rott ◽  
Teresa Ibarzábal Y Donángelo
Keyword(s):  
Antarctic Peninsula ◽  
Warming Trend ◽  
Western Coast ◽  
Ice Shelf ◽  
Orkney Islands ◽  
Air Temperatures ◽  
Recent Climate ◽  
Summer Temperatures ◽  
The Antarctic ◽  
Larsen Ice Shelf

Air temperatures at the Marambio (MAR), Esperanza (ESP) and Matienzo (MAT) stations have been analyzed to investigate recent climate change on the eastern part of the Antarctic Peninsula. They are compared with data from the Oreadas station on the South Orkney Islands, the longest record available in Antarctica, and from the Faraday (FAR) station on the western coast of the Peninsula. Though the interannual variability is comparatively high and the stations are located in different climatic regimes, a pronounced warming trend shows up in all records. At MAR a temperature increase of 1.5°C has been observed since the beginning of the record in 1971. This is of similar magnitude to the increase at FAR on the west coast, which was 2.5°C for the longer period since 1945. The steady retreat and collapse of the northern Larsen Ice Shelf (LIS) coincided with this warming trend. of particular importance for the ice-shelf mass balance in this region are the summer temperatures which show a statistically significant warming trend at MAR and ESP. The representativity of the summer temperatures of MAR for northern LIS is confirmed by intercomparison with the parallel measurements at MAT which is located on the ice shelf.

scholarly journals A Refined Method to Analyze Insoluble Particulate Matter in Ice Cores, and Its Application to Diatom Sampling in the Antarctic Peninsula

2021 ◽  
Vol 9 ◽  
Author(s):  
Dieter Tetzner ◽  
Elizabeth R. Thomas ◽  
Claire S. Allen ◽  
Eric W. Wolff
Keyword(s):  
Particulate Matter ◽  
Antarctic Peninsula ◽  
Ice Cores ◽  
Particulate Material ◽  
New Method ◽  
Polycarbonate Membrane ◽  
Low Concentration ◽  
Annual Variations ◽  
Filtration System ◽  
The Antarctic

The insoluble particulate matter deposited on ice sheets provide key information to reconstruct past climate. The low concentration of some insoluble particulate matter, such as terrigenous particles and microfossils, challenges the efficiency of the recovery and the representativeness of the results. Here we present a new optimized method to extract, quantify and classify targeted low concentration insoluble particulate matter. Particle recovery rates and particle distribution were investigated using polystyrene particle standards filtered through Polycarbonate membrane filters and subsequently scanned in a scanning electron microscope. Experimental results in continuous and discrete sampling systems reveal consistent trends in the transport and removal of particulate material inside a filtration system. Statistical simulations are used to optimize the sample analyses required to achieve representative results. The analysis of diatoms in ice cores using this new method uncovered their potential to hold valuable climate records from the Antarctic Peninsula region. The data presented here evidence the presence of a measurable amount of marine diatoms with sub-annual variations, highlighting the potential of this record as a seasonal indicator. The new method presented provides an optimized and statistically representative approach for extracting, recovering and analyzing micrometre-sized, low-concentration insoluble particulate matter in ice.

scholarly journals Stable-Isotope/Air-Temperature relationships in Ice Cores from Dolleman Island and the Palmer Land Plateau, Antarctic Peninsula

1988 ◽  
Vol 10 ◽  
pp. 130-136 ◽  
Author(s):  
David A. Peel ◽  
Robert Mulvaney ◽  
Brian M. Davison
Keyword(s):  
Stable Isotope ◽  
Air Temperature ◽  
Antarctic Peninsula ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Quantitative Evidence ◽  
Considerable Uncertainty ◽  
Annual Variations ◽  
Regional Temperature

Whilst stable-isotope analysis of ice cores yields the best quantitative evidence for past climate, there remains considerable uncertainty about the detailed relationship between the isotopic composition and air temperature. Analysis of two ice cores from the Antarctic Peninsula (a 47.2 m core from the Palmer Land plateau – 74°01’S, 70°38’W, and a 32 m core from Dolleman Island–70°35.2’S, 60°55.5’W) has shown that an oxygen-isotope/ temperature relationship exists at a resolution of inter-annual variations during the period 1938–86. All the major regional temperature anomalies, known from climatic records at several stations, are visible in the isotope profiles, including the overall temperature increase between 1960 and 1980. An isotope–temperature gradient of 0.5–0.6‰/°C is indicated for the climatic interpretation of isotopic fluctuations in ice cores recovered from the region. This gradient is considerably smaller than that (0.95‰/°C) obtained from a comparison of spatial variations in the mean annual parameters. The discrepancy appears to be due mainly to an inherent biasing in the isotope profiles, which record temperature only during periods of snowfall. The effect is particularly severe in the winter months and can be expected in other areas of Antarctica where a significant part of the snow accumulation is cyclonic.

Stable-Isotope/Air-Temperature relationships in Ice Cores from Dolleman Island and the Palmer Land Plateau, Antarctic Peninsula

1988 ◽  
Vol 10 ◽  
pp. 130-136 ◽  
Author(s):  
David A. Peel ◽  
Robert Mulvaney ◽  
Brian M. Davison
Keyword(s):  
Stable Isotope ◽  
Air Temperature ◽  
Antarctic Peninsula ◽  
Isotope Analysis ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Quantitative Evidence ◽  
Considerable Uncertainty ◽  
Annual Variations ◽  
Regional Temperature

Whilst stable-isotope analysis of ice cores yields the best quantitative evidence for past climate, there remains considerable uncertainty about the detailed relationship between the isotopic composition and air temperature. Analysis of two ice cores from the Antarctic Peninsula (a 47.2 m core from the Palmer Land plateau – 74°01’S, 70°38’W, and a 32 m core from Dolleman Island–70°35.2’S, 60°55.5’W) has shown that an oxygen-isotope/ temperature relationship exists at a resolution of inter-annual variations during the period 1938–86. All the major regional temperature anomalies, known from climatic records at several stations, are visible in the isotope profiles, including the overall temperature increase between 1960 and 1980.An isotope–temperature gradient of 0.5–0.6‰/°C is indicated for the climatic interpretation of isotopic fluctuations in ice cores recovered from the region. This gradient is considerably smaller than that (0.95‰/°C) obtained from a comparison of spatial variations in the mean annual parameters. The discrepancy appears to be due mainly to an inherent biasing in the isotope profiles, which record temperature only during periods of snowfall. The effect is particularly severe in the winter months and can be expected in other areas of Antarctica where a significant part of the snow accumulation is cyclonic.

scholarly journals Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past temperature reconstructions

2015 ◽  
Vol 9 (1) ◽  
pp. 655-717 ◽  
Author(s):  
V. Masson-Delmotte ◽  
H. C. Steen-Larsen ◽  
P. Ortega ◽  
D. Swingedouw ◽  
T. Popp ◽  
...  
Keyword(s):  
19Th Century ◽  
North Atlantic ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Last Interglacial ◽  
West Greenland ◽  
North West ◽  
Recent Climate ◽  
Temperature Reconstructions

Abstract. Combined records of snow accumulation rate, δ18O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (north-west Greenland), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterize the isotope–temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ18O and accumulation variability is related to North Atlantic SST, and enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ18O shows multi-decadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ18O anomaly values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ18O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815–1825 and 1836–1846, which are also the driest 11-year periods. The NEEM accumulation and δ18O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multi-decadal accumulation–temperature and δ18O–temperature relationships for the strong warming period in 1979–2007. The accumulation sensitivity to temperature is estimated at 11 ± 2% °C−1 and the δ18O–temperature slope at 1.1 ± 0.2‰ °C−1, about twice larger than previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core.

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