Abstract

Stability of the stratospheric polar vortex in the winter–spring period is one of key factors of the duration and scales of stratospheric ozone depletion in a polar region. The Arctic polar vortex attains its peak intensity in winter, whereas the Antarctic vortex usually strengthens in early spring. As a result, large-scale ozone depletion occurs every year from August to November over the Antarctic, and short-term ozone loss occasionally occurs from January to March over the Arctic. In this work, we analyze the reason for the high strength and stability of the Antarctic polar vortex in the winter–spring period. A good agreement between the seasonal variations in the temperature of the subtropical lower stratosphere and in the zonal wind in the lower subpolar and polar stratosphere in the Southern Hemisphere is shown on the basis of ERA-Interim reanalysis data. The results of numerical simulations with the PlaSim-ICMMG-1.0 model show acceleration of zonal wind in the subpolar region with an increase in the temperature of the subtropical stratosphere. Thus, the winter–spring strengthening of the Antarctic polar vortex occurs due to an increase in the stratospheric equator-to-pole temperature gradient caused by the seasonal increase in the temperature of the lower subtropical stratosphere in this period.

中文翻译：

---

下亚热带平流层温度对南极极涡动力学的影响

摘要

平流层极涡在冬春季节的稳定性是极地平流层臭氧消耗持续时间和尺度的关键因素之一。北极极涡在冬季达到峰值，而南极涡通常在初春时增强。结果，南极每年八月至十一月都会发生大规模的臭氧消耗，而北极一月至三月间偶尔会发生短期臭氧损失。在这项工作中，我们分析了南极极涡在冬季到春季具有高强度和稳定性的原因。根据ERA-Interim的再分析资料，显示了亚热带下平流层温度的季节变化与南半球下亚极平流层和极地平流层的纬向风的季节变化之间的良好一致性。用PlaSim-ICMMG-1.0模型进行的数值模拟结果表明，随着亚热带平流层温度的升高，亚极地区的纬向风加速。因此，南极极涡的冬春季增强是由于平流层赤道极间温度梯度的增加所引起的，该平流层至赤道极温度梯度是由该时期下亚热带平流层温度的季节性升高引起的。0模型显示了随着亚热带平流层温度升高，亚极地区纬向风加速。因此，南极极涡的冬春季增强是由于平流层赤道极间温度梯度的增加所引起的，该平流层至赤道极温度梯度是由该时期下亚热带平流层温度的季节性升高引起的。0模型显示了随着亚热带平流层温度升高，亚极地区纬向风加速。因此，南极极涡的冬春季增强是由于平流层赤道极间温度梯度的增加所引起的，该平流层至赤道极温度梯度是由该时期下亚热带平流层温度的季节性升高引起的。