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

Refractory black carbon aerosols (rBC) emittedby biomass burning (fires) and fossil fuel combustion, affectglobal climate and atmospheric chemistry. In the SouthernHemisphere (SH), rBC is transported in the atmospherefrom low- and mid-latitudes to Antarctica and deposited tothe polar ice sheet prese...

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Bibliographic Details
Published in:Atmospheric Chemistry and Physics
Main Authors: Bisiaux, MM, Edwards, R, McConnell, JR, Curran, MAJ, van Ommen, TD, Smith, AM, Neumann, TA, Pasteris, DR, Penner, JE, Taylor, K
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus 2012
Subjects:
Earth Sciences
Physical geography and environmental geoscience
Glaciology
Antarctic
Indian
Law Dome
Pacific
Antarc*
Antarctica
ice core
Ice Sheet
Online Access:https://doi.org/10.5194/acp-12-4107-2012
http://ecite.utas.edu.au/79568
Description
Summary:Refractory black carbon aerosols (rBC) emittedby biomass burning (fires) and fossil fuel combustion, affectglobal climate and atmospheric chemistry. In the SouthernHemisphere (SH), rBC is transported in the atmospherefrom low- and mid-latitudes to Antarctica and deposited tothe polar ice sheet preserving a history of emissions and atmospherictransport. Here, we present two high-resolutionAntarctic rBC ice core records drilled from the West AntarcticIce Sheet divide and Law Dome on the periphery of theEast Antarctic ice sheet. Separated by ~3500 km, the recordsspan calendar years 1850-2001 and reflect the rBC distributionover the Indian and Pacific ocean sectors of the SouthernOcean. Concentrations of rBC in the ice cores displayedsignificant variability at annual to decadal time scales, notablyin ENSO-QBO and AAO frequency bands. The delayobserved between rBC and ENSO variability suggestedthat ENSO does not directly affect rBC transport, but rathercontinental hydrology, subsequent fire regimes, and aerosolemissions. From 1850 to 1950, the two ice core records wereuncorrelated 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. Thedecrease in ice-core rBC from the 1950s to late 1980s displayssimilarities with inventories of SH rBC grass fires andbiofuel emissions, which show reduced emission estimatesover that period.

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