Climatology of Arctic and Antarctic Polar Vortices Using Elliptical Diagnostics
Climatology of Arctic and Antarctic Polar Vortices Using Elliptical Diagnostics
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使用椭圆诊断的北极和南极极涡气候学
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
W. Randel
中科院分区：
文献类型：
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作者：
D. Waugh;W. Randel
气候结构和年际变化，北极和南极平流层极涡的椭圆诊断应用于超过19年的位涡数据的分析研究。椭圆诊断定义的面积，中心，伸长率，和每个漩涡的方向，并用于量化它们的结构和演变。诊断提供了一个新的观点，众所周知的差异，在气候结构的极涡。虽然这两个涡旋都在秋季到初冬形成，但北极涡旋的寿命较短，并且比南极涡旋早一个多月分解。有实质性的差异，扭曲的涡从纬向对称，北极涡是位移更远的极，是比南极涡拉长。南极涡旋的畸变有一个仲冬极小值，而北极涡旋的畸变在其生命周期中不断增加。涡旋的年际变化也有很大的差异：南极涡旋的变化很小，除了在春季涡旋崩溃，而北极涡旋是高度可变的整个生命周期，特别是在冬末。诊断还揭示了以前研究中不明显的特征。在某些时期，涡旋的气候位置会发生大的纬向移动（先向西，然后向东）：北极涡旋的初冬，南极涡旋的冬末到春季。此外，在初冬，低平流层北极涡旋中心有两个优先的转向，并且涡旋可以迅速地从一个转向另一个。在平流层中上部，大的极移和大的涡伸长都与小的涡面积有关，但极移和涡伸长之间的相关性很小。
The climatological structure, and interannual variability, of the Arctic and Antarctic stratospheric polar vortices are examined by analysis of elliptical diagnostics applied to over 19 yr of potential vorticity data. The elliptical diagnostics define the area, center, elongation, and orientation of each vortex and are used to quantify their structure and evolution. The diagnostics offer a novel view of the well-known differences in the climatological structure of the polar vortices. Although both vortices form in autumn to early winter, the Arctic vortex has a shorter life span and breaks down over a month before the Antarctic vortex. There are substantial differences in the distortion of the vortices from zonal symmetry; the Arctic vortex is displaced farther off the pole and is more elongated than the Antarctic vortex. While there is a midwinter minimum in the distortion of the Antarctic vortex, the distortion of the Arctic vortex increases during its life cycle. There are also large differences in the interannual variability of the vortices: the variability of the Antarctic vortex is small except during the spring vortex breakdown, whereas the Arctic vortex is highly variable throughout its life cycle, particularly in late winter. The diagnostics also reveal features not apparent in previous studies. There are periods when there are large zonal shifts (westward then eastward) in the climatological locations of the vortices: early winter for the Arctic vortex, and late winter to spring for the Antarctic vortex. Also, there are two preferred longitudes of the center of the lower-stratospheric Arctic vortex in early winter, and the vortex may move rapidly from one to the other. In the middle and upper stratosphere large displacements off the pole and large elongation of the vortex are both associated with a small vortex area, but there is very little correlation between displacement off the pole and elongation of the vortex.