气候变化领域集成服务门户(CCPortal): Climatological impact of the Brewer-Dobson circulation on the N2O budget in WACCM, a chemical reanalysis and a CTM driven by four dynamical reanalyses

CCPortal

DOI	10.5194/acp-20-12609-2020
	Climatological impact of the Brewer-Dobson circulation on the N2O budget in WACCM, a chemical reanalysis and a CTM driven by four dynamical reanalyses
	Minganti D.; Chabrillat S.; Christophe Y.; Errera Q.; Abalos M.; Prignon M.; E. Kinnison D.; Mahieu E.
发表日期	2020
ISSN	1680-7316
起始页码	12609
结束页码	12631
卷号	20 期号:21
英文摘要	The Brewer Dobson circulation (BDC) is a stratospheric circulation characterized by upwelling of tropospheric air in the tropics, poleward flow in the stratosphere, and downwelling at mid and high latitudes, with important implications for chemical tracer distributions, stratospheric heat and momentum budgets, and mass exchange with the troposphere. As the photochemical losses of nitrous oxide (N2O) are well known, model differences in its rate of change are due to transport processes that can be separated into the mean residual advection and the isentropic mixing terms in the transformed Eulerian mean (TEM) framework. Here, the climatological impact of the stratospheric BDC on the longlived tracer N2O is evaluated through a comparison of its TEM budget in the Whole Atmosphere Community Climate Model (WACCM), in a chemical reanalysis of the Aura Microwave Limb Sounder version 2 (BRAM2) and in a chemistry transport model (CTM) driven by four modern reanalyses: the European Centre for Medium-Range Weather Forecasts Interim reanalysis (ERA-Interim; Dee et al., 2011), the Japanese 55-year Reanalysis (JRA-55; Kobayashi et al., 2015), and the Modern-Era Retrospective analysis for Research and Applications version 1 (MERRA; Rienecker et al., 2011) and version 2 (MERRA-2; Gelaro et al., 2017). The effects of stratospheric transport on the N2O rate of change, as depicted in this study, have not been compared before across this variety of datasets and have never been investigated in a modern chemical reanalysis. We focus on the seasonal means and climatological annual cycles of the two main contributions to the N2O TEM budget: the vertical residual advection and the horizontal mixing terms. The N2O mixing ratio in the CTM experiments has a spread of approximately 20% in the middle stratosphere, reflecting the large diversity in the mean age of air obtained with the same CTM experiments in a previous study. In all datasets, the TEM budget is closed well; the agreement between the vertical advection terms is qualitatively very good in the Northern Hemisphere, and it is good in the Southern Hemisphere except above the Antarctic region. The datasets do not agree as well with respect to the horizontal mixing term, especially in the Northern Hemisphere where horizontal mixing has a smaller contribution in WACCM than in the reanalyses. WACCM is investigated through three model realizations and a sensitivity test using the previous version of the gravity wave parameterization. The internal variability of the horizontal mixing inWACCM is large in the polar regions and is comparable to the differences between the dynamical reanalyses. The sensitivity test has a relatively small impact on the horizontal mixing term, but it significantly changes the vertical advection term and produces a less realistic N2O annual cycle above the Antarctic. In this region, all reanalyses show a large wintertime N2O decrease, which is mainly due to horizontal mixing. This is not seen with WACCM, where the horizontal mixing term barely contributes to the TEM budget. While we must use caution in the interpretation of the differences in this region (where the reanalyses show large residuals of the TEM budget), they could be due to the fact that the polar jet is stronger and is not tilted equatorward in WACCM compared with the reanalyses. We also compare the interannual variability in the horizontal mixing and the vertical advection terms between the different datasets. As expected, the horizontal mixing term presents a large variability during austral fall and boreal winter in the polar regions. In the tropics, the interannual variability of the vertical advection term is much smaller in WACCM and JRA-55 than in the other experiments. The large residual in the reanalyses and the disagreement between WACCM and the reanalyses in the Antarctic region highlight the need for further investigations on the modeling of transport in this region of the stratosphere. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	atmospheric chemistry; atmospheric circulation; atmospheric dynamics; climate effect; climate modeling; climatology; heat budget; nitrous oxide; stratosphere-troposphere interaction
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/247426
作者单位	Royal Belgian Institute for Space Aeronomy, BIRA-IASB, Brussels, 1180, Belgium; Earth Physics and Astrophysics Department, Universidad Complutense de Madrid, Madrid, 28040, Spain; Institute of Astrophysics and Geophysics, University of Liège, Liège, 4000, Belgium; National Center for Atmospheric Research, Boulder, CO 80301, United States
推荐引用方式 GB/T 7714	Minganti D.,Chabrillat S.,Christophe Y.,et al. Climatological impact of the Brewer-Dobson circulation on the N2O budget in WACCM, a chemical reanalysis and a CTM driven by four dynamical reanalyses[J],2020,20(21).
APA	Minganti D..,Chabrillat S..,Christophe Y..,Errera Q..,Abalos M..,...&Mahieu E..(2020).Climatological impact of the Brewer-Dobson circulation on the N2O budget in WACCM, a chemical reanalysis and a CTM driven by four dynamical reanalyses.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(21).
MLA	Minganti D.,et al."Climatological impact of the Brewer-Dobson circulation on the N2O budget in WACCM, a chemical reanalysis and a CTM driven by four dynamical reanalyses".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.21(2020).