Geomagnetic activity signatures in wintertime stratosphere wind, temperature, and wave response
Geomagnetic activity signatures in wintertime stratosphere wind, temperature, and wave response
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DOI：
10.1002/jgrd.50236
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发表时间：
2013-03-16
影响因子：
4.4
通讯作者：
Rodger, C. J.
中科院分区：
文献类型：
--
作者：
Seppala, A.;Lu, H.;Rodger, C. J.
我们分析了ERA-40和ERA中期气象再分析资料，以获得地磁活动在北半球延冬(11-3月)纬向平均纬向风、温度和Eliassen-Palm通量中的特征。我们发现，对于较高的地磁活动水平，平流层极涡在冬末变得更强，更多的行星波被折射到赤道。统计上有意义的信号首次出现在12月，并持续到3月，随着时间的推移，信号向极地传播，尽管由于可用数据量有限(类似于50年)，仍存在一些不确定性。我们的结果还表明，地磁对行星波传播的影响倾向于在初冬平流层背景气流相对稳定或极涡较强且扰动较小的情况下发生。这些情况通常发生在高太阳辐照度周期条件或西风准两年振荡条件下。
We analyzed ERA-40 and ERA Interim meteorological re-analysis data for signatures of geomagnetic activity in zonal mean zonal wind, temperature, and Eliassen-Palm flux in the Northern Hemisphere extended winter (November-March). We found that for high geomagnetic activity levels, the stratospheric polar vortex becomes stronger in late winter, with more planetary waves being refracted equatorward. The statistically significant signals first appear in December and continue until March, with poleward propagation of the signals with time, even though some uncertainty remains due to the limited amount of data available (similar to 50 years). Our results also indicated that the geomagnetic effect on planetary wave propagation has a tendency to take place when the stratosphere background flow is relatively stable or when the polar vortex is stronger and less disturbed in early winter. These conditions typically occur during high solar irradiance cycle conditions or westerly quasi-biennial oscillation conditions.