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Titel |
A 2000-year annual record of snow accumulation rates for Law Dome, East Antarctica |
VerfasserIn |
J. Roberts, C. Plummer, T. Vance, T. van Ommen, A. Moy, S. Poynter, A. Treverrow, M. Curran, S. George |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 11, no. 5 ; Nr. 11, no. 5 (2015-05-05), S.697-707 |
Datensatznummer |
250117281
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Publikation (Nr.) |
copernicus.org/cp-11-697-2015.pdf |
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Zusammenfassung |
Accurate high-resolution records of snow accumulation rates in Antarctica are
crucial for estimating ice sheet mass balance and subsequent sea level
change. Snowfall rates at Law Dome, East Antarctica, have been linked with
regional atmospheric circulation to the mid-latitudes as well as regional
Antarctic snowfall. Here, we extend the length of the Law Dome accumulation record from 750
years to 2035 years, using recent annual layer dating that extends to 22 BCE. Accumulation rates were calculated as the ratio of measured to modelled
layer thicknesses, multiplied by the long-term mean accumulation rate. The
modelled layer thicknesses were based on a power-law vertical strain rate
profile fitted to observed annual layer thickness. The periods 380–442,
727–783 and 1970–2009 CE have above-average snow accumulation rates,
while 663–704, 933–975 and 1429–1468 CE were below average, and
decadal-scale snow accumulation anomalies were found to be relatively common
(74 events in the 2035-year record). The calculated snow accumulation rates
show good correlation with atmospheric reanalysis estimates, and significant
spatial correlation over a wide expanse of East Antarctica, demonstrating
that the Law Dome record captures larger-scale variability across a large
region of East Antarctica well beyond the immediate vicinity of the Law Dome
summit. Spectral analysis reveals periodicities in the snow accumulation
record which may be related to El Niño–Southern Oscillation (ENSO) and Interdecadal Pacific
Oscillation (IPO) frequencies. |
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