气候变化领域集成服务门户(CCPortal): Upper stratospheric ClO and HOCl trends (2005-2020): Aura Microwave Limb Sounder and model results

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DOI	10.5194/acp-22-4779-2022
	Upper stratospheric ClO and HOCl trends (2005-2020): Aura Microwave Limb Sounder and model results
	Froidevaux, Lucien; Kinnison, Douglas E.; Santee, Michelle L.; Millan, Luis F.; Livesey, Nathaniel J.; Read, William G.; Bardeen, Charles G.; Orlando, John J.; Fuller, Ryan A.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	4779
结束页码	4799
卷号	22 期号:7 页码:21
英文摘要	We analyze Aura Microwave Limb Sounder (MLS) monthly zonal mean time series of ClO and HOCl between 50 degrees S and 50 degrees N to estimate upper stratospheric trends in these chlorine species from 2005 through 2020. We compare these observations to those from the Whole Atmosphere Community Climate Model version 6 (WACCM6), run under the specified dynamics configuration. The model sampling follows the MLS coverage in space and local time. We use version 5 MLS ClO zonal mean daytime profiles and similarly binned daytime ClO model profiles from 32 to 1.5 hPa. For MLS HOCl, we use the version 5 offline product derived from daily zonal mean radiances rather than averaged level-2 profiles; MLS HOCl is scientifically useful between 10 and 2 hPa, and the HOCl monthly zonal means are separated into day and night for comparison to WACCM6. We find good agreement (mostly within similar to 10 %) between the climatological MLS ClO daytime distributions and the model ClO climatology for 2005-2020. The model HOCl climatology, however, underestimates the MLS HOCl climatology by about 30 %. This could well be caused by a combination of fairly large systematic uncertainties in both the model-assumed rate constant for the formation of HOCl and the MLS HOCl retrievals themselves. The model daytime ClO trends versus latitude and pressure agree quite well with those from MLS. MLS-derived near-global upper stratospheric daytime trends between 7 and 2 hPa are -0.73 +/- 0.40 % yr(-1) for ClO and -0.39 +/- 0.35 % yr(-1) for HOCl, with 2 sigma uncertainty estimates used here. The corresponding model decreases are somewhat faster than observed (although the difference is not statistically significant), with trend values of -0.85 +/- 0.45 % yr(-1) for ClO and -0.64 +/- 0.37 % yr(-1) for HOCl. Both data and model results point to a faster trend in ClO than in HOCl. The MLS ClO trends are consistent with past estimates of upper stratospheric ClO trends from satellite and ground-based microwave data. As discussed in the past, trends in other species (in particular, positive trends in CH4 and H2O) can lead to a ClO decrease that is faster than the decrease in total inorganic chlorine. Regarding trends in HOCl, positive trends in HO2 can lead to a faster rate of formation for HOCl as a function of time, which partially offsets the decreasing trend in active chlorine. The decreasing trends in upper stratospheric ClO and HOCl provide additional confirmation of the effectiveness of the Montreal Protocol and its amendments, which have led to the early stages of an expected long-term ozone recovery from the effects of ozone-depleting substances.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000780952400001
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/273119
作者单位	California Institute of Technology; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); National Center Atmospheric Research (NCAR) - USA
推荐引用方式 GB/T 7714	Froidevaux, Lucien,Kinnison, Douglas E.,Santee, Michelle L.,et al. Upper stratospheric ClO and HOCl trends (2005-2020): Aura Microwave Limb Sounder and model results[J],2022,22(7):21.
APA	Froidevaux, Lucien.,Kinnison, Douglas E..,Santee, Michelle L..,Millan, Luis F..,Livesey, Nathaniel J..,...&Fuller, Ryan A..(2022).Upper stratospheric ClO and HOCl trends (2005-2020): Aura Microwave Limb Sounder and model results.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(7),21.
MLA	Froidevaux, Lucien,et al."Upper stratospheric ClO and HOCl trends (2005-2020): Aura Microwave Limb Sounder and model results".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.7(2022):21.