DOI: 10.1016/j.palaeo.2013.05.024
论文题名: Change in the intensity of low-salinity water inflow from the Bay of Bengal into the Eastern Arabian Sea from the Last Glacial Maximum to the Holocene: Implications for monsoon variations
作者: Mahesh B.S. ; Banakar V.K.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2014
卷: 397 起始页码: 31
结束页码: 37
语种: 英语
英文关键词: Arabian Sea
; Indian monsoon
; Paleo-salinity
; Paleo-Sea Surface Temperature
; Planktonic foraminifera δ18O and Mg/Ca
英文摘要: A 100-400km wide region of the coastal Eastern Arabian Sea (EAS), off the west-coast of India, is characterized by a low-salinity tongue formed by the inflow of low-salinity surface water from the Bay of Bengal (BoB). This low-salinity tongue is largely driven by the sea level higher in BoB than in the Arabian Sea and by alongshore pressure gradient between southern- and northern-EAS, and is expected to respond to summer monsoon freshwater flux to the bay. Here, we report past variation in the relative intensity of summer- and winter-monsoons based on changes in the north-south salinity gradient within this low-salinity tongue. The salinity gradient is estimated from paired measurement of δ18O and Mg/Ca in Globigerinoides sacculifer extracted from sediment cores collected at northern high-salinity and southern low-salinity locations within this tongue.The Last Glacial Maximum (LGM) to peak-Holocene δ18O and sea surface temperature gradients at both locations are ~-2‰ and +2°C respectively, while the sea surface salinity gradient at northern-EAS is 0.5psu higher than in the southern-EAS, suggesting distinctly different SSS structure in the LGM-EAS. The north-south surface salinity gradient was also larger by ~0.5psu during the LGM (1.2psu) as compared to the gradient during the Holocene (0.7psu). Increased north-south surface salinity gradient during the LGM suggests diminished flow of low-salinity water into the coastal EAS caused by combined effect of decreased freshening of the BoB and reduced seasonal mountain-river discharge into the EAS. Such surface hydrographic conditions in the coastal EAS clearly indicate significantly weakened summer monsoons and strengthened winter monsoons during the LGM. © 2013 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69442
Appears in Collections: 过去全球变化的重建
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作者单位: CSIR-National Institute of Oceanography, Dona Paula, Goa 403 004, India; National Centre for Antarctic and Ocean Research, Headland Sada, Vasco-da-Gama, Goa, India
Recommended Citation:
Mahesh B.S.,Banakar V.K.. Change in the intensity of low-salinity water inflow from the Bay of Bengal into the Eastern Arabian Sea from the Last Glacial Maximum to the Holocene: Implications for monsoon variations[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2014-01-01,397