Variability of black carbon deposition to the East Antarctic Plateau, AD 1800–2000

Abstract. Refractory black carbon aerosols (rBC) from biomass burning and fossil fuel combustion are deposited to the Antarctic ice sheet and preserve a history of emissions and long-range transport from low latitudes. Antarctic ice core rBC records may thus provide information with respect to past combustion aerosol emissions and atmospheric circulation. Here, we present six East Antarctic ice core records of rBC concentrations and fluxes covering the last two centuries with approximately annual resolution (cal. yr. 1800 to 2000). The ice cores were drilled in disparate regions of the high East Antarctic ice sheet, at different elevations and net snow accumulation rates. Annual rBC concentrations were log-normally distributed and geometric means of annual concentrations ranged from 0.10 to 0.18 μg kg−1. Average rBC fluxes were determined over the time periods 1800 to 2000 and 1963 to 2000 and ranged from 3.4 to 15.5 μg kg−1 m−2 a−1 and 3.6 to 21.8 μg kg−1 m−2 a−1 respectively. Geometric-mean concentrations spanning 1800 to 2000 increased linearly with elevation at a rate of 0.025 μg kg−1/500 m. Spectral analysis of the records revealed significant decadal scale variability, which at several sites was comparable to decadal ENSO variability.

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Variability of black carbon deposition to the East Antarctic Plateau, 1800–2000 AD

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3799-2012 ◽

2012 ◽

Vol 12 (8) ◽

pp. 3799-3808 ◽

Cited By ~ 29

Author(s):

M. M. Bisiaux ◽

R. Edwards ◽

J. R. McConnell ◽

M. R. Albert ◽

H. Anschütz ◽

...

Keyword(s):

Black Carbon ◽

Geometric Mean ◽

Ice Core ◽

Ice Sheet ◽

Ice Cores ◽

Snow Accumulation ◽

Antarctic Ice Sheet ◽

Decadal Scale ◽

History Of ◽

Aerosol Emissions

Abstract. Refractory black carbon aerosols (rBC) from biomass burning and fossil fuel combustion are deposited to the Antarctic ice sheet and preserve a history of emissions and long-range transport from low- and mid-latitudes. Antarctic ice core rBC records may thus provide information with respect to past combustion aerosol emissions and atmospheric circulation. Here, we present six East Antarctic ice core records of rBC concentrations and fluxes covering the last two centuries with approximately annual resolution (cal. yr. 1800 to 2000). The ice cores were drilled in disparate regions of the high East Antarctic ice sheet, at different elevations and net snow accumulation rates. Annual rBC concentrations were log-normally distributed and geometric means of annual concentrations ranged from 0.10 to 0.18 μg kg−1. Average rBC fluxes were determined over the time periods 1800 to 2000 and 1963 to 2000 and ranged from 3.4 to 15.5 μg m−2 a−1 and 3.6 to 21.8 μg m−2 a−1, respectively. Geometric mean concentrations spanning 1800 to 2000 increased linearly with elevation at a rate of 0.025 μg kg−1/500 m. Spectral analysis of the records revealed significant decadal-scale variability, which at several sites was comparable to decadal ENSO variability.

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Changes in black carbon deposition to Antarctica from two high-resolution ice core records, 1850–2000 AD

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-4107-2012 ◽

2012 ◽

Vol 12 (9) ◽

pp. 4107-4115 ◽

Cited By ~ 72

Author(s):

M. M. Bisiaux ◽

R. Edwards ◽

J. R. McConnell ◽

M. A. J. Curran ◽

T. D. Van Ommen ◽

...

Keyword(s):

High Resolution ◽

Black Carbon ◽

Atmospheric Chemistry ◽

Ice Core ◽

Ice Sheet ◽

Ice Cores ◽

Fire Regimes ◽

Antarctic Ice Sheet ◽

Continental Hydrology ◽

Ice Core Records

Abstract. Refractory black carbon aerosols (rBC) emitted by biomass burning (fires) and fossil fuel combustion, affect global climate and atmospheric chemistry. In the Southern Hemisphere (SH), rBC is transported in the atmosphere from low- and mid-latitudes to Antarctica and deposited to the polar ice sheet preserving a history of emissions and atmospheric transport. Here, we present two high-resolution Antarctic rBC ice core records drilled from the West Antarctic Ice Sheet divide and Law Dome on the periphery of the East Antarctic ice sheet. Separated by ~3500 km, the records span calendar years 1850–2001 and reflect the rBC distribution over the Indian and Pacific ocean sectors of the Southern Ocean. Concentrations of rBC in the ice cores displayed significant variability at annual to decadal time scales, notably in ENSO-QBO and AAO frequency bands. The delay observed between rBC and ENSO variability suggested that ENSO does not directly affect rBC transport, but rather continental hydrology, subsequent fire regimes, and aerosol emissions. From 1850 to 1950, the two ice core records were uncorrelated but were highly correlated from 1950 to 2002 (cross-correlation coefficient at annual resolution: r = 0.54, p < 0.01) due to a common decrease in rBC variability. The decrease in ice-core rBC from the 1950s to late 1980s displays similarities with inventories of SH rBC grass fires and biofuel emissions, which show reduced emission estimates over that period.

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Inferring paleo-accumulation records from ice-core data by an adjoint method: application to James Ross Island's ice core

Climate of the Past Discussions ◽

10.5194/cpd-10-3821-2014 ◽

2014 ◽

Vol 10 (5) ◽

pp. 3821-3845 ◽

Cited By ~ 1

Author(s):

C. Martín ◽

R. Mulvaney ◽

G. H. Gudmundsson ◽

H. Corr

Keyword(s):

Vertical Velocity ◽

Adjoint Method ◽

Ice Core ◽

Synthetic Data ◽

Ice Cores ◽

Snow Accumulation ◽

Polar Regions ◽

History Of ◽

Climatic Record ◽

Accumulation History

Abstract. Ice cores contain a record of snow precipitation that includes information about past atmospheric circulation and mass imbalance in the polar regions. We present a novel adjoint method to reconstruct a climatic record by both optimally dating an ice-core and deriving from it a detailed accumulation history. The motivation of our work is the recent application of phase sensitive radar which measures the vertical velocity of an ice column. The velocity is dependent on the history of subsequent snow accumulation, compaction and compression; and in our inverse formulation of this problem, measured vertical velocity profiles can be utilized directly thereby reducing the uncertainty introduced by ice flow modelling. We first apply our method to synthetic data in order to study its capability and the effect of noise and gaps in the data on retrieved accumulation history. The method is then applied to the ice core retrieved from James Ross Island, Antarctica. We show that the method is robust and that the results depend on quality of the age-depth observations and the derived flow regime around the core site. The method facilitates the incorporation of increasing detail provided by ice-core analysis together with observed full-depth velocity in order to construct a complete climatic record of the polar regions.

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An 800 year high-resolution black carbon ice-core record from Lomonosovfonna, Svalbard

10.5194/acp-2018-244 ◽

2018 ◽

Cited By ~ 2

Author(s):

Dimitri Osmont ◽

Isabel A. Wendl ◽

Loïc Schmidely ◽

Michael Sigl ◽

Carmen P. Vega ◽

...

Keyword(s):

High Resolution ◽

Black Carbon ◽

20Th Century ◽

Biomass Burning ◽

Ice Core ◽

Ice Cores ◽

The Arctic ◽

Snow Albedo ◽

Decadal Scale

Abstract. Produced by the incomplete combustion of fossil fuel and biomass, black carbon (BC) contributes to Arctic warming by reducing snow albedo and thus triggering a snow-albedo feedback leading to increased snow melting. Therefore, it is of high importance to assess past BC emissions to better understand and constrain their role. However, only few long-term BC records are available from the Arctic, mainly originating from Greenland ice cores. Here, we present the first long-term and high-resolution refractory black carbon (rBC) record from Svalbard, derived from the analysis of two ice cores drilled at the Lomonosovfonna ice field in 2009 (LF-09) and 2011 (LF-11) and covering 800 years of atmospheric emissions. Our results show that rBC concentrations strongly increased from 1860 on due to anthropogenic emissions and reached two maxima, at the end of the 19th century and in the middle of the 20th century. No increase in rBC concentrations during the last decades was observed, which is corroborated by atmospheric measurements elsewhere in the Arctic but contradicts a previous study from another ice core from Svalbard. While melting may affect BC concentrations during periods of high temperatures, rBC concentrations remain well-preserved prior to the 20th century due to lower temperatures inducing little melt. Therefore, the preindustrial rBC record (before 1800), along with ammonium (NH4+), formate (HCOO−) and specific organic markers (vanillic acid (VA) and p-hydroxybenzoic acid (p-HBA)), was used as a proxy for biomass burning. Despite numerous single events, no long-term trend was observed over the time period 1222–1800 for rBC and NH4+. In contrast, formate, VA and p-HBA experience multi-decadal peaks reflecting periods of enhanced biomass burning. Most of the background variations and single peak events are corroborated by other ice-core records from Greenland and Siberia. We suggest that the paleofire record from the LF ice core primarily reflects biomass burning episodes from Northern Eurasia, induced by decadal-scale climatic variations.

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Air Content Of The Byrd Core And Past Changes In The West Antarctic Ice Sheet

Annals of Glaciology ◽

10.1017/s0260305500002901 ◽

1982 ◽

Vol 3 ◽

pp. 269-273 ◽

Cited By ~ 42

Author(s):

D. Raynaud ◽

I. M. Whillans

Keyword(s):

Stable Isotope ◽

Accumulation Rate ◽

Ice Core ◽

Ice Sheet ◽

Ice Cores ◽

Isotope Ratios ◽

Ice Age ◽

Gas Content ◽

Stable Isotope Ratios ◽

Antarctic Ice Sheet

Analyses of ice cores taken from the Antarctic ice sheet can provide information on the environmental conditions under which the ice was formed. New results from measurements of gas content and stable isotope ratios in the Byrd station ice core are discussed and interpreted in terms of past iceflow changes.165 selected ice samples from 32 different depth levels along the core were processed for total gas content V and stable isotope ratios. This large dataset is used to discuss the variability and significance of the values of V at different depths. The short term variations of V are mainly explained by heterogeneities of the pore volume when the firn pores close off.The general trends in the values of V with depth are then used to investigate the possibility of past changes in the ice sheet. They suggest near-steady flow during the past few tens of thousands of years and that a thickening of about 200 to 250 m occurred in this area of the ice sheet at the end of the last ice age. This thickening could be due to a change in the accumulation rate.

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Topographic control of regional accumulation rate variability at South Pole and implications for ice-core interpretation

Annals of Glaciology ◽

10.3189/172756404781814050 ◽

2004 ◽

Vol 39 ◽

pp. 214-218 ◽

Cited By ~ 23

Author(s):

Gordon S. Hamilton

Keyword(s):

Accumulation Rate ◽

Ice Core ◽

Ice Sheet ◽

Ice Cores ◽

Snow Accumulation ◽

Topographic Effects ◽

South Pole ◽

Accumulation Rates ◽

Surface Slope ◽

Ice Dynamics

AbstractSnow-accumulation rates are known to be sensitive to local changes in ice-sheet surface slope because of the effect of katabatic winds. These topographic effects can be preserved in ice cores that are collected at non-ice-divide locations. The trajectory of an ice-core site at South Pole is reconstructed using measurements of ice-sheet motion to show that snow was probably deposited at places of different surface slope during the past 1000 years. Recent accumulation rates, derived from shallow firn cores, vary along this trajectory according to surface topography, so that on a relatively steep flank mean annual accumulation is ∼18% smaller than on a nearby topographic depression. These modern accumulation rates are used to reinterpret the cause of accumulation rate variability with time in the long ice-core record as an ice-dynamics effect and not a climate-change signal. The results highlight the importance of conducting ancillary ice-dynamics measurements as part of ice-coring programs so that topographic effects can be deconvolved from potential climate signals.

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The Chemical Stratigraphy of Polar Ice Sheets — A Method of Dating Ice Cores

Journal of Glaciology ◽

10.3189/s0022143000011175 ◽

1981 ◽

Vol 27 (95) ◽

pp. 3-9

Author(s):

A. T. Wilson ◽

C. H. Hendy

Keyword(s):

Accumulation Rate ◽

Ice Core ◽

Ice Sheet ◽

Ice Cores ◽

Antarctic Ice Sheet ◽

The Core ◽

Similar Work ◽

Polar Ice Sheets ◽

Vostok Station ◽

East Antarctic Ice Sheet

AbstractStudies of the chemical stratigraphy in the snow near Vostok station, which is near the centre of the East Antarctic ice sheet, show that sodium exhibits annual concentration differences of up to a factor of ten. Similar work on the 952 m Vostok ice core enabled accumulation rates along selected parts of the core to be determined. This in turn enables the core to be dated. The accumulation rate in this central region of the East Antarctic ice sheet for the last 50000 years has been determined and is presented. An interesting result is that the accumulation rate during the last glacial period is only half that in post-glacial times. Results from the bottom of the core provide some evidence of a past surge in the East Antarctic ice sheet.

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Inferring palaeo-accumulation records from ice-core data by an adjoint-based method: application to James Ross Island's ice core

Climate of the Past ◽

10.5194/cp-11-547-2015 ◽

2015 ◽

Vol 11 (3) ◽

pp. 547-557 ◽

Cited By ~ 3

Author(s):

C. Martín ◽

R. Mulvaney ◽

G. H. Gudmundsson ◽

H. Corr

Keyword(s):

Vertical Velocity ◽

Ice Core ◽

Synthetic Data ◽

Ice Cores ◽

Snow Accumulation ◽

Polar Regions ◽

Novel Approach ◽

History Of ◽

Climatic Record ◽

Snow Precipitation

Abstract. Ice cores contain a record of snow precipitation that includes information about past atmospheric circulation and mass imbalance in the polar regions. We present a novel approach to reconstruct a climatic record – by both optimally dating an ice core and deriving from it a detailed accumulation history – that uses an adjoint-based method. The motivation of our work is the recent application of phase-sensitive radar which measures the vertical velocity of an ice column. The velocity is dependent on the history of subsequent snow accumulation, compaction and compression; in our inverse formulation of this problem, measured vertical velocity profiles can be utilized directly, thereby reducing the uncertainty introduced by ice-flow modelling. We first apply our method to synthetic data in order to study its capability and the effect of noise and gaps in the age–depth observations. The method is then applied to the ice core retrieved from James Ross Island, Antarctica. We show that the method is robust and that the results depend on the quality of the age–depth observations and the derived flow regime around the core site. The method facilitates the incorporation of increasing detail provided by ice-core analysis together with observed full-depth velocity in order to construct a complete climatic record of the polar regions.

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Future Antarctic snow accumulation trend is dominated by atmospheric synoptic-scale events

Communications Earth & Environment ◽

10.1038/s43247-020-00062-x ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Quentin Dalaiden ◽

Hugues Goosse ◽

Jan T. M. Lenaerts ◽

Marie G. P. Cavitte ◽

Naomi Henderson

Keyword(s):

Large Scale ◽

Ice Sheet ◽

Snow Accumulation ◽

Synoptic Scale ◽

Antarctic Ice Sheet ◽

Decadal Scale ◽

Antarctic Snow ◽

Atmospheric Moisture Budget ◽

The Antarctic ◽

Accumulation Trend

AbstractOver the last century, the increase in snow accumulation has partly mitigated the total dynamic Antarctic Ice Sheet mass loss. However, the mechanisms behind this increase are poorly understood. Here we analyze the Antarctic Ice Sheet atmospheric moisture budget based on climate reanalysis and model simulations to reveal that the interannual variability of regional snow accumulation is controlled by both the large-scale atmospheric circulation and short-lived synoptic-scale events (i.e. storm systems). Yet, when considering the entire continent at the multi-decadal scale, only the synoptic-scale events can explain the recent and expected future snow accumulation increase. In a warmer climate induced by climate change, these synoptic-scale events transport air that can contain more humidity due to the increasing temperatures leading to more precipitation on the continent. Our findings highlight that the multi-decadal and interannual snow accumulation variability is governed by different processes, and that we thus cannot rely directly on the mechanisms driving interannual variations to predict long-term changes in snow accumulation in the future.

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