气候变化领域集成服务门户(CCPortal): Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients

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DOI	10.1029/2020JD033158
	Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients
	Yang H.; Lohmann G.; Lu J.; Gowan E.J.; Shi X.; Liu J.; Wang Q.
发表日期	2020
ISSN	2169897X
卷号	125 期号:16
英文摘要	An abundance of evidence indicates that the tropics are expanding. Despite many attempts to decipher the cause, the underlying dynamical mechanism driving tropical expansion is still not entirely clear. Here, based on observations, multimodel simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5) and purposefully designed numerical experiments, the variations and trends of the tropical width are explored from a regional perspective. We find that the width of the tropics closely follows the displacement of oceanic midlatitude meridional temperature gradients (MMTG). Under global warming, as a first-order response, the subtropical ocean experiences more surface warming because of the mean Ekman convergence of anomalously warm water. The enhanced subtropical warming, which is partially independent of natural climate oscillations, such as the Pacific Decadal Oscillation, leads to poleward advance of the MMTG and drives the tropical expansion. Our results, supported by both observations and model simulations, imply that global warming may have already significantly contributed to the ongoing tropical expansion, especially over the ocean-dominant Southern Hemisphere. © 2020. The Authors.
英文关键词	Global Warming; Jet Stream; Mid-latitude Temperature Gradients; Ocean Circulation; Storm Track; Tropical Expansion
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185838
作者单位	Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, United States; Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY, United States
推荐引用方式 GB/T 7714	Yang H.,Lohmann G.,Lu J.,et al. Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients[J],2020,125(16).
APA	Yang H..,Lohmann G..,Lu J..,Gowan E.J..,Shi X..,...&Wang Q..(2020).Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients.Journal of Geophysical Research: Atmospheres,125(16).
MLA	Yang H.,et al."Tropical Expansion Driven by Poleward Advancing Midlatitude Meridional Temperature Gradients".Journal of Geophysical Research: Atmospheres 125.16(2020).