Mechanisms of stratospheric ozone depletion at high and middle latitudes

自1995年以来，在日本北海道岛的陆别和Moshiri天文台以及瑞典基鲁纳使用地面FTIR仪器测量了HF、HCl、ClONO2、HNO3和O3。在日本观察到的所有这些物种都有明显的季节变化。即7 - 9月列量最小，2 - 4月列量最大。这些物种是通过长寿命的微量物种光解产生的。从秋天到春天，这些物种丰度的增加基本上是由于行星波向极地输送。除了冬季和春季柱丰度普遍增加外，这两个季节的变异较大。根据位涡分析，在2 - 4月间，极涡中的气团偶尔被输送到日本北部上空。在这些病例中，观察到HCl/HF比下降和ClONO2/HF比增加。这些结果与包括极地平流层云（PSCs）上的非均相反应的三维化学和输运模型（CTM）计算的结果基本一致。1 - 4月臭氧的逐日变化与包括极地平流层云（PSCs）上的非均相反应的CTM计算的结果基本一致。3月底，这些CTM计算的O3量比未进行非均相反应的计算结果低2%。当极地涡旋中的气团被输送到陆别上空时，差异可达6%。这些结果表明，来自北极的空气输送对中纬度地区观测到的臭氧减少有很大的影响。

Measurements of HF, HCl, ClONO2, HNO3, and O3 were made using the Ground-based FTIR instruments at Rikubetsu and Moshiri observatories on the island of Hokkaido, Japan, and at Kiruna Sweden since 1995. All these species observed in Japan show marked seasonal variations. Namely the column amounts are minimum in July-September and reach maximum values in February-April. These species are produced through photolysis of long lived trace species. The increases of the abundance of these species from fall to spring are basically due to poleward transport by planetary waves. In addition to the general increase of the column abundances in winter and spring, the variability is larger in these seasons. Based on the potential vorticity (PV) analysis, air mass in the polar vortex was occasionally transported to over the north part of Japan between February and April. On these cases, a decrease in the HCl/HF ratio and an increase in the ClONO2/HF ratio were observed. These results were consistent with those calculated using the three-dimensional chemistry and transport model (CTM) in which heterogeneous reactions on polar stratospheric clouds (PSCs) were included The observed day to day variation of O3 between January and April was generally in good agreement with that calculated using the CTM which included the heterogeneous reactions on PSCs. These CTM calculated O3 amounts were lower than those calculated without the heterogeneous reactions by 2 % at the end of March. When air mass in the polar vortex was transported to over Rikubetsu the difference was as large as 6 %. These results suggest the size of influence from the transport of air from the Arctic that was responsible for the ozone decrease observed at midlatitudes.