On the Reproducibility of the September 2002 Vortex Splitting Event in the Antarctic Stratosphere Achieved without Satellite Observations
On the Reproducibility of the September 2002 Vortex Splitting Event in the Antarctic Stratosphere Achieved without Satellite Observations
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论2002年9月无卫星观测的南极平流层涡旋分裂事件的再现性
DOI：
10.1002/qj.3193
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发表时间：
2017
影响因子：
8.9
通讯作者：
and C. Kobayashi
中科院分区：
文献类型：
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作者：
S. Noguchi;and C. Kobayashi
为了突出卫星观测的影响，对日本55年再分析（JRA-55）和没有同化卫星观测的等效再分析（JRA-55 C; C代表“常规”观测）进行了比较。作为极端事件的可探测性问题的一个说明性的例子，我们报告的平流层突然变暖（SSW）事件发生在2002年9月下旬的再现性，这一事件是第一次观察到的独特的涡旋分裂事件在南极平流层。通过JRA-55的数据同化系统，即使在没有卫星观测的情况下，也能很好地捕捉到这次变暖事件的初始趋势和随后的恢复过程。然而，JRA-55 C的变暖并不满足主要SSW事件的标准，除了极涡缺乏分裂行为之外。在SSW事件期间，JRA-55和JRA-55 C之间的显著差异，其特征是从平流层上部到对流层突然出现近正压结构，这反映了观测地点的地理分布。此外，在极涡的物理状态和观测锚定效应的几个差异是一致的建议，这SSW是由一个高度变形的极涡的灾难性崩溃的建议，最近的一些工作。
To highlight the impact of satellite measurements, a comparison between the Japanese 55‐year reanalysis (JRA‐55) and its equivalent without the assimilation of satellite observations (JRA‐55C; C stands for ‘conventional’ observations) was conducted. As an illustrative example of the detectability problem of extreme events, we report on the reproducibility of a stratospheric sudden warming (SSW) event that occurred in late September 2002; this event represents the first observed unique vortex splitting event in the Antarctic stratosphere. Through the data assimilation system of JRA‐55, the initial tendency of this warming event and the following recovery process were well captured even when no satellite observations were used. However, the warming in JRA‐55C does not satisfy the criteria for a major SSW event besides the lack of splitting behaviour in the polar vortex. A prominent difference between JRA‐55 and JRA‐55C during the SSW event, which was characterized by the sudden appearance of a nearly barotropic structure from the upper stratosphere to the troposphere, was found over the Western Hemisphere reflecting the geographic distribution of observational sites. Moreover, several differences in the precursory state of the polar vortex and the observational anchoring effect are consistent with the proposal that this SSW was caused by the catastrophic breakdown of a highly deformed polar vortex as suggested by some recent works.