气候变化领域集成服务门户(CCPortal): Role of the stratospheric chemistry-climate interactions in the hot climate conditions of the Eocene

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DOI	10.5194/cp-15-1187-2019
	Role of the stratospheric chemistry-climate interactions in the hot climate conditions of the Eocene
	Szopa S.; Thiéblemont R.; Bekki S.; Botsyun S.; Sepulchre P.
发表日期	2019
ISSN	18149324
起始页码	1187
结束页码	1203
卷号	15 期号:4
英文摘要	The stratospheric ozone layer plays a key role in atmospheric thermal structure and circulation. Although stratospheric ozone distribution is sensitive to changes in trace gases concentrations and climate, the modifications of stratospheric ozone are not usually considered in climate studies at geological timescales. Here, we evaluate the potential role of stratospheric ozone chemistry in the case of the Eocene hot conditions. Using a chemistry-climate model, we show that the structure of the ozone layer is significantly different under these conditions (4×CO2 climate and high concentrations of tropospheric N2O and CH4). The total column ozone (TCO) remains more or less unchanged in the tropics whereas it is found to be enhanced at mid- and high latitudes. These ozone changes are related to the stratospheric cooling and an acceleration of stratospheric Brewer-Dobson circulation simulated under Eocene climate. As a consequence, the meridional distribution of the TCO appears to be modified, showing particularly pronounced midlatitude maxima and a steeper negative poleward gradient from these maxima. These anomalies are consistent with changes in the seasonal evolution of the polar vortex during winter, especially in the Northern Hemisphere, found to be mainly driven by seasonal changes in planetary wave activity and stratospheric wave-drag. Compared to a preindustrial atmospheric composition, the changes in local ozone concentration reach up to 40% for zonal annual mean and affect temperature by a few kelvins in the middle stratosphere. As inter-model differences in simulating deep-past temperatures are quite high, the consideration of atmospheric chemistry, which is computationally demanding in Earth system models, may seem superfluous. However, our results suggest that using stratospheric ozone calculated by the model (and hence more physically consistent with Eocene conditions) instead of the commonly specified preindustrial ozone distribution could change the simulated global surface air temperature by as much as 14%. This error is of the same order as the effect of non-CO2 boundary conditions (topography, bathymetry, solar constant and vegetation). Moreover, the results highlight the sensitivity of stratospheric ozone to hot climate conditions. Since the climate sensitivity to stratospheric ozone feedback largely differs between models, it must be better constrained not only for deep-past conditions but also for future climates. © Author(s) 2019.
语种	英语
scopus关键词	atmospheric chemistry; atmospheric circulation; climate conditions; climate modeling; concentration (composition); cooling; Eocene; ozone; paleoclimate; stratosphere; trace gas; troposphere
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146802
作者单位	Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France; Laboratoire Atmosphère, Milieux, Observations Spatiales, Institut Pierre Simon Laplace, LATMOS/IPSL, CNRS-UVSQ, Sorbonne Université, Guyancourt and Paris, France; Department of Geosciences, University of Tübingen, Tübingen, Germany
推荐引用方式 GB/T 7714	Szopa S.,Thiéblemont R.,Bekki S.,et al. Role of the stratospheric chemistry-climate interactions in the hot climate conditions of the Eocene[J],2019,15(4).
APA	Szopa S.,Thiéblemont R.,Bekki S.,Botsyun S.,&Sepulchre P..(2019).Role of the stratospheric chemistry-climate interactions in the hot climate conditions of the Eocene.Climate of the Past,15(4).
MLA	Szopa S.,et al."Role of the stratospheric chemistry-climate interactions in the hot climate conditions of the Eocene".Climate of the Past 15.4(2019).