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| Titel |
Summer insolation is the primary driver for orbital-scale dust storm
variability in East Asia |
| VerfasserIn |
Sascha Serno, Gisela Winckler, Robert F. Anderson, Samuel L. Jaccard, Stephanie S. Kienast, Gerald H. Haug  |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250122328
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| Publikation (Nr.) |
 EGU/EGU2016-1336.pdf |
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| Zusammenfassung |
| Eolian dust plays an important role in the global climate system through its influence on
radiation, albedo and precipitation properties, and through delivering micronutrients like iron
to the oceans. Glacial periods of Earth’s climate are recognized to be dustier than
interglacials, but the conditions leading to greater dust mobilization are poorly defined. We
present a high-resolution dust flux record based on 230Th-normalised 4He flux from Ocean
Drilling Program (ODP) site 882 in the Subarctic North Pacific covering the last 170,000
years. Today, dust storms in the vast dry regions of East Asia are almost exclusively
springtime phenomena, due to a specific set of climate conditions driven by the seasonal
evolution of the meridional temperature gradient between high and low latitudes.
The dust flux record points to high dust storm activity in East Asia during cold
periods, with highest dust flux during Marine Isotope Stages 4 and 5d. We interpret
periods of higher dust supply as the result of an expansion of the dust season into
the summer, primarily controlled by reduced summer insolation at high latitudes
and resulting lower air temperatures in Siberia over orbital timescales. Changes
in the extent of the large Northern Hemisphere ice sheets in North America and
Fennoscandinavia, and atmospheric teleconnections, act as a secondary control. On
millennial timescales, the occurrence of Heinrich Stadials 1 and 11 signals during the last two
terminations in Subarctic North Pacific dust records indicates that dust flux variability over
millennial timescales was influenced by climate changes in the North Atlantic. |
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