Glacial/interglacial changes of Southern Hemisphere wind circulation from the geochemistry of South American dust

Gili, Stefania; Gaiero, Diego M.; Goldstein, Steven L.; Chemale, Farid; Jweda, Jason; Kaplan, Michael R.; Becchio, Raúl; Koester, Edinei

doi:10.1016/j.epsl.2017.04.007

Cited by 68 publications

(131 citation statements)

References 47 publications

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“…From a geochemical point of view, the Nd and Pb radiogenic isotope composition of sediments in the region of middle and northern central western Argentina (Gili et al, ) is also compatible with Holocene dust (Gaiero et al, ; Gili et al, , ; Smith et al, ), whereas the Sr isotopic composition is slightly more radiogenic. Therefore, a contribution from these subtropical deposits is compatible with our results.…”

Section: Resultsmentioning

confidence: 99%

“…For the glacial periods of the middle and late Pleistocene, a number of studies (Basile et al, ; Delmonte et al, ; Delmonte et al, ; Delmonte et al, ; Gabrielli et al, ; Grousset et al, ; Sugden et al, ; Vallelonga et al, ) converge toward the important role of South America as major glacial dust source to Antarctica during MIS 2 and earlier glaciations. Detailed field studies in South America (Gaiero, ; Gaiero et al, ; Gili et al, , ) suggested that the most important glacial source areas for Antarctica are the northern Patagonian region—dominated by westerly winds—and the southern part of central western Argentina—where the intensified westerly “Zonda winds” promoted deflation (Gili et al, ). Independent support was recently provided by single‐grain mineralogical data for the last glacial period (Delmonte et al, ) that for the first time allowed including the exposed Patagonian continental shelf as a deflation source during MIS 2 and excluding the mineralogically incompatible lake Eyre region of Australia.…”

Section: Resultsmentioning

confidence: 99%

“…Sr‐Nd Holocene isotope data—showing a less radiogenic Nd isotope composition and similar Sr isotopic composition with respect to MIS 2—are compatible with a contribution from lower latitudes inside South America (Delmonte et al, ), as first suggested by Gaudichet et al (, ) on the basis of mineralogical data. These include the Andean Puna‐Altiplano Plateau (Delmonte et al, ; Gaiero et al, ; Gili et al, , ). This possibility is also supported by lithium solubility data (Siggaard‐Andersen et al, ), whereas Rare Earth Element patterns are variable and point to multiple different sources since 15 kyr BP (Gabrielli et al, ; Wegner et al, ).…”

Section: Resultsmentioning

confidence: 99%

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Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Paleari

Delmonte

Andó

et al. 2019

Geophysical Research Letters

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We analyzed the single‐grain mineralogical composition of aeolian dust transported to central East Antarctica for provenance purposes. Comparison with data from the last glacial period shows for the first time disappearance of carbonates during the Holocene related to sea level rise and suppressed deflation from the Argentinean continental shelf, exposed during Marine Isotope Stage 2. Zeolites, related to alteration of volcanic glass in the subglacial/periglacial environment of Patagonia, show a similar behavior. The remaining minerals, remarkably similar between the two climatic periods, are compatible with a Pampean and Patagonian provenance, but Holocene data show a more pronounced volcanic and metamorphic imprint and presence of minerals related to warm climate weathering environments compatible with an additional contribution from subtropical latitudes of South America. These results do not imply a major large‐scale reorganization of atmospheric circulation after the last climatic transition.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Paleari

Delmonte

Andó

et al. 2019

Geophysical Research Letters

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“…Among those high-latitude environments (Bullard et al, 2016), the Patagonia desert is a current active source of dust. Patagonia, the desert located south of the Colorado River (~39S) in southern South America (SSA), has been singled out as the largest source of dust found in ice cores in East Antarctica through the Pleistocene (Albani et al, 2016;Basile et al, 1997;Delmonte et al, 2004;Delmonte et al, 2017;Gili et al, 2016Gili et al, , 2017Grousset et al, 1992). While Patagonia remains currently an active source, there have been very few studies dedicated to understanding the transport of dust and its impacts.…”

Section: Introductionmentioning

confidence: 99%

Temporal Characterization of Dust Activity in the Central Patagonia Desert (Years 1964–2017)

Gassó

Torres

2019

JGR Atmospheres

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Dust emitted from the southern end of South America (SSA) is transported long distances over the Southern Ocean and deposited over this marine ecosystem. Whether the nutrients released through dissolution have a biogeochemical impact is a question with biological as well as climate implications, yet there is no clear answer. Additionally, the provenance of dust recently found in accumulated snow in East Antarctica is still a matter of debate. The Patagonia desert in SSA is the likely source, but there are no detailed records documenting dust activity in this area, thereby preventing any definite assessments. Here we provide a survey of modern dust activity of the largest dust source in SSA, the lake Colhué Huapi in central Patagonia. We analyzed five decades (1964–2017) of surface synoptic observations (World Meteorological Weather Present weather codes) and concurrent satellite aerosol detection (UV Aerosol Index from the Total Ozone Monitoring Sensor and Ozone Monitoring Instrument detectors, 1978–2017). We assessed the seasonal, year‐to‐year variability and periods of major dust activity. Several periods of enhanced activity were found with roughly 2‐ to 10‐year duration each (1970–1976, 1989–1994, 1996–1997, and 1999–2017). While dust activity peaks during summer months, wintertime activity during the most active years can well exceed the summer average of nonactive years. For a period of coincident satellite observations, the occurrence of at least three periods of high activity is confirmed. Since satellite detection is more sensitive to mesoscale dust events, the large events that occurred during these periods brought abundant dust into the SW South Atlantic. Satellites with polar orbits tend to under detect dust events in this region. Significant cloudiness obstructs the direct view of dust, and dust activity tends to occur late in the afternoon after the overpass of polar satellites. These observations have a time span adequate for comparison with transport models and modern records of dust samples collected in East Antarctica. The results contribute to a better understanding of the dynamic of modern dust transport in the Southern Hemisphere, the provenance of dust found in Antarctica, and the provenance of eolian nutrients into the Southern Ocean.

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“…The driver of eolian activity can be linked to Quaternary climate variability and increased aridity in the Andean foreland and Argentine Pampas plain during the Holocene (Iriondo, 1999). Quaternary glacial/interglacial cycles drove regional wind systems to change strength and latitudinal positions, affecting their capacity for erosion and transport of sand and mineral dust from the sources to depositional areas (Figure 8; Gili et al, 2017). Eolian deposition spans most of the Holocene to ca.…”

Section: Aridification Drives Orogen Parallel Eolian Activitymentioning

confidence: 99%

Fluvial and Eolian Sediment Mixing During Changing Climate Conditions Recorded in Holocene Andean Foreland Deposits From Argentina (31–33°S)

et al. 2019

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Continental drainage systems archive complex records of rock uplift, source area relief, precipitation, glaciation, and carbon cyclicity driven largely by tectonics and climate. Significant progress has been made in linking such external environmental forcings to the geomorphic expression of landscapes and the stratigraphic record of depositional basins in coastal and offshore areas. However, there are large uncertainties in the degree to which sediment dispersal processes can modify signals between the erosional sources and the depositional sinks. We investigate a Holocene sediment transfer zone with contrasting fluvial and eolian sediment transport mechanisms to understand how river and wind processes impact the propagation of environmental signals in continentalscale drainage systems. To quantify these processes, we employ sediment fingerprinting methods for unconsolidated sand samples (detrital zircon U-Pb geochronology), incorporate sediment mixing models, and correlate the findings with the regional geologic and geomorphic framework. Three contrasting source regions deliver sediment to the Andean foreland: volcanic rocks of the Frontal Cordillera, sedimentary rocks of the Precordillera, and metamorphic basement of the Sierras Pampeanas. Although all samples of Holocene eolian dunes accurately record sediment input from three fluvial source regions, spatial variations in U-Pb results are consistent with north-directed paleowinds, whereby river sediments from Frontal Cordillera sources are transported northward and progressively mixed with river sediments from Precordillera and Sierras Pampeanas sources. In contrast, samples of modern rivers show progressive southward (downstream) mixing along a large axial fluvial system. Sediment mixing induced by eolian transport and reworking of various sources is likely a critical, climate-modulated process in the propagation of environmental signals, potentially involving the aliasing of tectonic signals, local storage and recycling of synorogenic river sediment, and cyclical patterns of sediment starvation and delivery to distal zones of accumulation.

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Glacial/interglacial changes of Southern Hemisphere wind circulation from the geochemistry of South American dust

Cited by 68 publications

References 47 publications

Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Aeolian Dust Provenance in Central East Antarctica During the Holocene: Environmental Constraints From Single‐Grain Raman Spectroscopy

Temporal Characterization of Dust Activity in the Central Patagonia Desert (Years 1964–2017)

Fluvial and Eolian Sediment Mixing During Changing Climate Conditions Recorded in Holocene Andean Foreland Deposits From Argentina (31–33°S)

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