DOI: 10.1007/s00382-015-2652-8
Scopus记录号: 2-s2.0-84959087732
论文题名: Validation of δ18O as a proxy for past monsoon rain by multi-GCM simulations
作者: Midhun M. ; Ramesh R.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 46, 期: 2017-05-06 起始页码: 1371
结束页码: 1385
语种: 英语
英文关键词: Amount effect
; Indian summer monsoon
; Isotope enabled GCMs
; Model intercomparison
; Paleoclimatology
; Speleothem
; Stable isotopes
英文摘要: Stable oxygen isotope ratios (δ18O) of tree cellulose and speleothem carbonate are useful proxies for past monsoon rain in many tropical regions, as a decrease in rain δ18O is observed with increase in rainfall on a monthly time scale. This amount effect varies spatially; therefore a local calibration, with actual measurements of rain amount and its δ18O is required. Such observations, however, are quite limited in space and time. To circumvent this difficulty, many isotope enabled general circulation models (GCMs) are used to aid the interpretation of 18O proxies; nevertheless, all such simulations taken together are yet to be evaluated against observations over the Indian summer monsoon (ISM) region. Here we examine ten such GCM simulations archived by the stable water isotope INtercomparison Group, phase 2. The spatial patterns of simulated ISM rainfall and its δ18O are in good agreement with the limited observations available. Simulations nudged with observed wind fields show better skill in reproducing the observed spatio-temporal pattern of rainfall and its δ18O. A large discrepancy is observed in the magnitude of the simulated amount effect over the Indian subcontinent between the models and observation, probably because models simulate the spatial distribution of monsoon precipitation differently. Nudged simulations show that interannual variability of rainfall δ18O at proxy sites are controlled by either regional (rather than local) rainfall or upstream rain out. Interannual variability of rainfall δ18O over the East Asian region is well correlated with ENSO, while it is only weakly correlated over the Indian sub-continent. © 2015, Springer-Verlag Berlin Heidelberg. 资助项目: ISRO, Indian Space Research Organisation, Department of Space
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53811
Appears in Collections: 过去全球变化的重建
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作者单位: Geosciences Division, Physical Research Laboratory, Ahmedabad, India; Indian Institute of Technology Gandhinagar, VGEC Campus, Ahmedabad, India; Sardar Patel University, Vallabh Vidyanagar, India
Recommended Citation:
Midhun M.,Ramesh R.. Validation of δ18O as a proxy for past monsoon rain by multi-GCM simulations[J]. Climate Dynamics,2016-01-01,46(2017-05-06)