DOI: 10.1073/pnas.1922602117
论文题名: Enriched East Asian oxygen isotope of precipitation indicates reduced summer seasonality in regional climate and westerlies
作者: Chiang J.C.H. ; Herman M.J. ; Yoshimura K. ; Fung I.Y.
刊名: Proceedings of the National Academy of Sciences of the United States of America
ISSN: 0027-8424
出版年: 2020
卷: 117, 期: 26 起始页码: 14745
结束页码: 14750
语种: 英语
英文关键词: East Asia
; Monsoon
; Paleoclimate
; Westerlies
Scopus关键词: oxygen
; Article
; climate
; climate change
; environmental impact
; mathematical model
; migration
; phase transition
; priority journal
; seasonal variation
; summer
英文摘要: Speleothem oxygen isotope records over East Asia reveal apparently large and rapid paleoclimate changes over the last several hundred thousand years. However, what the isotopic variation actually represent in terms of the regional climate and circulation is debated. We present an answer that emerges from an analysis of the interannual variation in amount-weighted annual δ18O of precipitation over East Asia as simulated by an isotope-enabled model constrained by large-scale atmospheric reanalysis fields. 18O-enriched years have reduced summer seasonality both in terms of precipitation isotopes and in the large-scale circulation. Changes occur between June and October, where the δ18O of precipitation (δ18Op) transitions from the isotopically heavier winter to the lighter summer regime. For 18O-enriched years, this transition is less pronounced. Variations in precipitation amount alone are insufficient to explain the amount-weighted annual δ18Op between 18O-enriched and 18O-depleted years. Reduced summer seasonality is also expressed in the low-level monsoonal southerlies and upper-level westerlies; for the latter, the northward migration across the Tibetan Plateau in the summer is less pronounced. Our result thus implicates the westerlies across the plateau as the proximate cause of East Asian paleomonsoon changes, manifested as a modulation of its summer peak. © 2020 National Academy of Sciences. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164144
Appears in Collections: 气候变化与战略
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作者单位: Chiang, J.C.H., Department of Geography, University of California, Berkeley, CA 94720, United States; Herman, M.J., Department of Geography, University of California, Berkeley, CA 94720, United States; Yoshimura, K., Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, 277-8574, Japan; Fung, I.Y., Department of Earth and Planetary Sciences, University of California, Berkeley, CA 94720, United States
Recommended Citation:
Chiang J.C.H.,Herman M.J.,Yoshimura K.,et al. Enriched East Asian oxygen isotope of precipitation indicates reduced summer seasonality in regional climate and westerlies[J]. Proceedings of the National Academy of Sciences of the United States of America,2020-01-01,117(26)