Defining the geochemical composition of the EPICA Dome C ice core dust during the last glacial‐interglacial cycle

Marino, F.; Castellano, E.; Ceccato, D.; Deckker, Patrick De; Delmonte, Barbara; Ghermandi, Grazia; Maggi, Valter; Petit, Jean‐Robert; Revel-Rolland, Marie; Udisti, Roberto

doi:10.1029/2008gc002023

Cited by 52 publications

(73 citation statements)

References 43 publications

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“…2d). Southern South America may be the dominant dust supplier to Antarctica during cold conditions while Australia also contributed during warm times (Revel-Rolland et al, 2006;Lambert et al, 2008;Marino et al, 2008). Similar glacialinterglacial cycles of dust flux were also observed for the equatorial Pacific (Fig.…”

Section: Broad Coupling and Decoupled Aspects Of Hemispheric Climatessupporting

confidence: 63%

“…Analyses of the air bubbles yield a high-resolution history of the atmospheric concentrations of greenhouse gases (Petit et al, 1999;Siegenthaler et al, 2005;Loulergue et al, 2008;Luthi et al, 2008). The eolian dust in the ice bears valuable information on atmospheric circulation and climate conditions of the dust source regions in the Southern Hemisphere (Revel-Rilland et al, 2006;Lambert et al, 2008;Marino et al, 2008). Correlating China loess and Antarctica ice records provides an ideal opportunity to evaluate the hemispheric climate link over the past 800 ka, the main aim of this study.…”

Section: Introductionmentioning

confidence: 99%

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Strong asymmetry of hemispheric climates during MIS-13 inferred from correlating China loess and Antarctica ice records

et al. 2009

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Abstract. We correlate the China loess and Antarctica ice records to address the inter-hemispheric climate link over the past 800 ka. The results show a broad coupling between Asian and Antarctic climates at the glacial-interglacial scale. However, a number of decoupled aspects are revealed, among which marine isotope stage (MIS) 13 exhibits a strong anomaly compared with the other interglacials. It is characterized by unusually positive benthic oxygen (δ 18 O) and carbon isotope (δ 13 C) values in the world oceans, cooler Antarctic temperature, lower summer sea surface temperature in the South Atlantic, lower CO 2 and CH 4 concentrations, but by extremely strong Asian, Indian and African summer monsoons, weakest Asian winter monsoon, and lowest Asian dust and iron fluxes. Pervasive warm conditions were also evidenced by the records from northern high-latitude regions. These consistently indicate a warmer Northern Hemisphere and a cooler Southern Hemisphere, and hence a strong asymmetry of hemispheric climates during MIS-13. Similar anomalies of lesser extents also occurred during MIS-11 and MIS-5e. Thus, MIS-13 provides a case that the Northern Hemisphere experienced a substantial warming under relatively low concentrations of greenhouse gases. It suggests that the global climate system possesses a natural variability that is not predictable from the simple response of northern summer insolation and atmospheric CO 2 changes. During MIS-13, both hemispheres responded in different ways leading to anomalous continental, marine and atmospheric conditions at the global scale. The correlations also suggest that the marine δ 18 O record is not always a reliable indicator of the northern ice-volume changes, and that the asymmetry of hemispheric climates is one of the prominent factors controlCorrespondence to: Z. T. Guo (ztguo@mail.iggcas.ac.cn) ling the strength of Asian, Indian and African monsoon circulations, most likely through modulating the position of the inter-tropical convergence zone (ITCZ) and land-sea thermal contrasts.

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Section: Broad Coupling and Decoupled Aspects Of Hemispheric Climatessupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Strong asymmetry of hemispheric climates during MIS-13 inferred from correlating China loess and Antarctica ice records

et al. 2009

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“…Holocene dust sizes measured at these sites are all relatively coarse compared to the ∼ 2 µm modal values measured in the Vostok and EPICA Dome C ice cores from central East Antarctica (e.g., Delmonte et al, 2002). According to a range of geochemical and isotopic evidence, the East Antarctic plateau receives dust primarily from Patagonia, located approximately 6000-7000 km away, although other sources, such as Australia, may contribute during interglacial periods (Basile et al, 1997;Delmonte et al, 2004Delmonte et al, , 2008Revel-Rolland et al, 2006;Marino et al, 2008Marino et al, , 2009. Given the particle size similarities between WAIS Divide and other non-plateau sites, it seems plausible that much of Antarctica has a dust size signature that differs from that of central East Antarctica.…”

Section: Grain Size Distribution and Likely Dust Source(s) For West Amentioning

confidence: 99%

Centennial-scale variability of the Southern Hemisphere westerly wind belt in the eastern Pacific over the past two millennia

et al. 2014

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Abstract. We present the first high-resolution (sub-annual) dust particle data set from West Antarctica, developed from the West Antarctic Ice Sheet (WAIS) Divide deep ice core (79.468 • S, 112.086 • W), and use it to reconstruct changes in atmospheric circulation over the past 2400 years. We find a background dust flux of ∼ 4 mg m −2 year −1 and a mode particle size of 5-8 µm diameter. Through comparing the WAIS Divide record with other Antarctic ice core particle records, we observe that coastal and lower-elevation sites have higher dust fluxes and coarser particle size distributions (PSDs) than sites on the East Antarctic plateau, suggesting input from local dust sources at these lower-elevation sites. In order to explore the use of the WAIS Divide dust PSD as a proxy for past atmospheric circulation, we make quantitative comparisons between both mid-latitude zonal wind speed and West Antarctic meridional wind speed and the dust size record, finding significant positive interannual relationships. We find that the dust PSD is related to midlatitude zonal wind speed via cyclonic activity in the Amundsen Sea region. Using our PSD record, and through comparison with spatially distributed climate reconstructions from the Southern Hemisphere (SH) middle and high latitudes, we infer that the SH westerlies occupied a more southerly position from circa 1050 to 1400 CE (Common Era), coinciding with the Medieval Climate Anomaly (MCA). Subsequently, at ca. 1430 CE, the wind belt shifted equatorward, where it remained until the mid-to-late twentieth century. We find covariability between reconstructions of El Niño-Southern Oscillation (ENSO) and the mid-latitude westerly winds in the eastern Pacific, suggesting that centennial-scale circulation changes in this region are strongly influenced by the tropical Pacific. Further, we observe increased coarse particle deposition over the past 50 years, consistent with observations that the SH westerlies have been shifting southward and intensifying in recent decades.

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“…While geochemical provenance studies can be valuable for deducing the sources for different dust deposition sites, there is limited data (Grousset and Biscaye, 2005). For the present climate, information on long-range dust provenance for Antarctica is so far limited to the central East Antarctic Plateau, the main source being Argentina (Delmonte et al, 2007), with significant contribution from a secondary source which could be either the Puna-Altiplano Gaiero, 2008) or Australia (Marino et al, 2008). For the Antarctic cores, we chose our sources to be consistent with these model and observational studies (Table 3) influence both source areas in their time series, but at half the weight of the other records.…”

Section: Dust Variability Reconstruction Over 20th Century From Datamentioning

confidence: 99%

Observed 20th century desert dust variability: impact on climate and biogeochemistry

et al. 2010

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Abstract. Desert dust perturbs climate by directly and indirectly interacting with incoming solar and outgoing long wave radiation, thereby changing precipitation and temperature, in addition to modifying ocean and land biogeochemistry. While we know that desert dust is sensitive to perturbations in climate and human land use, previous studies have been unable to determine whether humans were increasing or decreasing desert dust in the global average. Here we present observational estimates of desert dust based on paleodata proxies showing a doubling of desert dust during the 20th century over much, but not all the globe. Large uncertainties remain in estimates of desert dust variability over 20th century due to limited data. Using these observational estimates of desert dust change in combination with ocean, atmosphere and land models, we calculate the net radiative effect of these observed changes (top of atmosphere) over the 20th century to be −0.14 ± 0.11 W/m 2 (1990-1999 vs. 1905-1914). The estimated radiative changeCorrespondence to: N. M. Mahowald (mahowald@cornell.edu) due to dust is especially strong between the heavily loaded 1980-1989 and the less heavily loaded 1955-1964 time periods (−0.57 ± 0.46 W/m 2 ), which model simulations suggest may have reduced the rate of temperature increase between these time periods by 0.11 • C. Model simulations also indicate strong regional shifts in precipitation and temperature from desert dust changes, causing 6 ppm (12 PgC) reduction in model carbon uptake by the terrestrial biosphere over the 20th century. Desert dust carries iron, an important micronutrient for ocean biogeochemistry that can modulate ocean carbon storage; here we show that dust deposition trends increase ocean productivity by an estimated 6% over the 20th century, drawing down an additional 4 ppm (8 PgC) of carbon dioxide into the oceans. Thus, perturbations to desert dust over the 20th century inferred from observations are potentially important for climate and biogeochemistry, and our understanding of these changes and their impacts should continue to be refined.

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Defining the geochemical composition of the EPICA Dome C ice core dust during the last glacial‐interglacial cycle

Cited by 52 publications

References 43 publications

Strong asymmetry of hemispheric climates during MIS-13 inferred from correlating China loess and Antarctica ice records

Strong asymmetry of hemispheric climates during MIS-13 inferred from correlating China loess and Antarctica ice records

Centennial-scale variability of the Southern Hemisphere westerly wind belt in the eastern Pacific over the past two millennia

Observed 20th century desert dust variability: impact on climate and biogeochemistry

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