Stratosphere‐Troposphere Exchange of Air Masses and Ozone Concentrations Based on Reanalyses and Observations
Stratosphere‐Troposphere Exchange of Air Masses and Ozone Concentrations Based on Reanalyses and Observations
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DOI：
10.1029/2021jd035159
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
Mingcheng Wang;Q. Fu
中科院分区：
文献类型：
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作者：
Mingcheng Wang;Q. Fu
这项研究估计了平流层-对流层交换（STE）的空气质量和臭氧浓度平均在2007年至2010年使用现代回顾分析研究和应用2（MERRA 2）和ERA 5再分析和观测。后者包括用于臭氧的微波临边探测器（MLS），用于温度的MLS和气象、电离层和气候星座观测系统（COSMIC），以及用于非绝热加热的A-Train测量。ERA 5再分析的大气层外向下臭氧通量为538 Tg年-1，MERRA 2再分析为543 Tg年-1，观测为528-539 Tg年-1，与以前的研究一致。然而，以前的研究没有考虑热带向上的臭氧通量。在这里，我们表明热带向上的臭氧通量为183-193 Tg year-1，它补偿了约35%的温带向下臭氧通量，不应被忽视。在考虑热带向上的臭氧通量后，ERA 5再分析的全球臭氧STE为346 Tg年-1，MERRA 2再分析为360 Tg年-1，观测为336-346 Tg年-1。这些估计值（347 ± 12 Tg年-1）可用作臭氧STE对对流层臭氧收支的贡献。我们还研究了云辐射对空气质量和臭氧的STE的影响。在380 K，云辐射效应增强向下通量的热带外再分析和观测，但减少和增强向上通量的热带再分析和观测，分别。热带地区的差异与再分析中缺少的热带对流层顶薄卷云有关。云辐射效应使全球臭氧STE增加了21%-29%。
This study estimates the stratosphere–troposphere exchange (STE) of air masses and ozone concentrations averaged over 2007 to 2010 using the Modern Era Retrospective‐Analyses for Research and Applications 2 (MERRA2) and ERA5 reanalyses, and observations. The latter includes Microwave Limb Sounder (MLS) for ozone, MLS and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) for temperatures, and A‐Train measurements for diabatic heating. The extratropical downward ozone fluxes are 538 Tg year−1 from the ERA5 reanalysis, 543 Tg year−1 from the MERRA2 reanalysis, and 528–539 Tg year−1 from the observations, consistent with previous studies. Previous studies, however, did not consider tropical upward ozone flux. Here we show that the tropical upward ozone flux is 183–193 Tg year−1, which compensates about 35% of the extratropical downward ozone fluxes and should not be neglected. After considering the tropical upward ozone flux, the global ozone STE is 346 Tg year−1 from the ERA5 reanalysis, 360 Tg year−1 from the MERRA2 reanalysis, and 336–346 Tg year−1 from the observations. Those estimates (347 ± 12 Tg year−1) can be used as the contribution of ozone STE to the tropospheric ozone budget. We also investigate cloud radiative effects on the STE of air mass and ozone. At 380 K, cloud radiative effects enhance downward fluxes in the extratropics from both reanalyses and observation, but reduce and enhance upward fluxes in the tropics from reanalyses and observation, respectively. The discrepancy in the tropics is related to the tropical tropopause layer thin cirrus that is missing in the reanalyses. We find that cloud radiative effects enhance the global ozone STE by about 21%–29%.