noaa-ocean-10495 Arabian Sea 20KYr Carbonate and Stable Isotope Data Overpeck, J.T.; Anderson, D.M.; Trumbore, S.E.; Prell, W.L. Arabian Sea 20KYr Carbonate and Stable Isotope Data 2010-11-03 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/10495 Investigator J.T. Overpeck Investigator D.M. Anderson Investigator S.E. Trumbore Investigator W.L. Prell earth science paleoclimate paleoceanography delta 18O,Globigerina bulloides,null,per mil,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 13C,Globigerina bulloides,null,per mil,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography carbonate,sediment,null,percent,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography carbonate,sediment,unspecified margin of error,percent,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography depth,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean oxygen isotopes earth science paleoclimate paleocean carbon isotopes geoscientificInformation Monsoon 27320 cal yr BP 2530 cal yr BP Complete 18 18.25 57.58 57.65 -820 -596 Ocean Indian Ocean RC27-14>LATITUDE 18.25>LONGITUDE 57.65 Ocean Indian Ocean RC27-23>LATITUDE 18>LONGITUDE 57.58 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Overpeck, J., D. Anderson, S. Trumbore, and W. Prell. 2010. The southwest Indian Monsoon over the last 18 000 years. Climate Dynamics, Vol. 12, No. 3, pp. 213-225. DOI: 10.1007/BF00211619

Previously published results suggest that the strength of the SW Indian Monsoon can vary significantly on century- to millennium time scales, an observation that has important implications for assessments of future climate and hydrologic change over densely populated portions of Asia. We present new, well-dated, multi-proxy records of past monsoon variation from three separate Arabian Sea sediment cores that span the last glacial maximum to late-Holocene. To a large extent, these records confirm earlier published suggestions that the monsoon strengthened in a series of abrupt events over the last deglaciation. However, our data provide a somewhat refined picture of when these events took place, and suggest the primacy of two abrupt increases in monsoon intensity, one between 13 and 12.5 ka, and the other between 10 and 9.5 ka. This conclusion is supported by the comparisons between our new marine data and published paleoclimatic records throughout the African-Asian monsoon region. The comparison of data sets further supports the assertion that maximum monsoon intensity lagged peak insolation forcing by about 3000 years, and extended from about 9.5 to 5.5 ka. The episodes of rapid monsoon intensification coincided with major shifts in North Atlantic-European surface temperatures and ice-sheet extent. This coincidence, coupled with new climate model experiments, suggests that the large land-sea thermal gradient needed to drive strong monsoons developed only after glacial conditions upstream of, and on, the Tibetan Plateau receded (cold North Atlantic sea-surface temperatures, European ice-sheets, and extensive Asian snow cover). It is likely that abrupt changes in seasonal soil hydrology were as important to past monsoon forcing as were abrupt snow-related changes in regional albedo. Our analysis suggests that the monsoon responded more linearly to insolation forcing after the disappearance of glacial boundary conditions, decreasing gradually after about 6 ka. Our data also support the possibility that significant century-scale decreases in monsoon intensity took place during the early to mid-Holocene period of enhanced monsoon strength, further highlighting the need to understand paleomonsoon dynamics before accurate assessments of future monsoon strength can be made. STUDY NOTES: High-resolution carbonate concentration and foraminiferal stable isotope data from 2 marine sediment cores in the Arabian Sea, ~150 km offshore Oman, as a proxy for SW Indian Monsoon strength over the past 20,000 years.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/overpeck1996/overpeck1996.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/overpeck1996/overpeck1996.xls USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11