Evaporation-precipitation changes in the eastern Arabian Sea for the last 68 ka: Implications on monsoon variability
DRS at CSIR-National Institute of Oceanography
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Title |
Evaporation-precipitation changes in the eastern Arabian Sea for the last 68 ka: Implications on monsoon variability
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Creator |
Govil, P.
Naidu, P.D. |
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Subject |
monsoon variability
sea surface temperature monsoon fluctuations monsoon system |
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Description |
Variations in sea surface temperature (SST), delta sup(18)O of sea water (delta sup(18)Ow), and salinity were reconstructed for the past 68 ka using a sediment core (AAS9/21) from the eastern Arabian Sea (EAS) in order to understand the changes in evaporation and precipitation associated with the monsoon system. The Mg/Ca-derived SST record varies by approx. 4 degrees C; it shows that marine isotope stage (MIS) 4 was warmer than MIS 3, that the Last Glacial Maximum was 4 degrees C cooler than the present, and that there was a 2 degrees C increase within the Holocene. MIS 4 records higher delta sup(18) OW and salinity values than MIS 2, suggesting variable flow of low-salinity Bay of Bengal flow into the EAS during glacial periods. The transition from MIS 4 to MIS 3 was marked with a conspicuous shift from higher to lower delta sup(18)Ow values, which reflects a decrease in the evaporation precipitation budget in the EAS, perhaps due to the strengthening of southwest monsoon. Monsoon reconstructions based on delta sup(18)Ow reveal that monsoon-driven precipitation was higher during MIS 3 and MIS 1 and was lower during MIS 2 and MIS 4. This is consistent with earlier monsoon reconstructions based on upwelling indices from the western Arabian Sea. However, the amplitude of monsoon fluctuations derived through upwelling indices and delta sup(18)Ow varies significantly, which may indicate spatial variability of monsoon rainfall
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Date |
2010-04-04T14:20:05Z
2010-04-04T14:20:05Z 2010 |
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Type |
Journal Article
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Identifier |
Paleoceanography, vol.25; 11 pp, doi:10.1029/2008PA001687
no http://drs.nio.org/drs/handle/2264/3575 |
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Language |
en
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Relation |
Paleoceanography_25_2010.jpg
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Rights |
An edited version of this paper was published by AGU. Copyright [2009] AGU. To view the published open abstract, go to http://dx.doi.org and enter the DOI.
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Publisher |
American Geophysical Union
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