Weak Stratospheric Polar Vortex Events Modulated by the Arctic Sea‐Ice Loss
Weak Stratospheric Polar Vortex Events Modulated by the Arctic Sea‐Ice Loss
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DOI：
10.1029/2018jd029222
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
K. Hoshi;J. Ukita;M. Honda;Tetsu Nakamura;K. Yamazaki;Y. Miyoshi;Ralf Jaiser
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文献类型：
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作者：
K. Hoshi;J. Ukita;M. Honda;Tetsu Nakamura;K. Yamazaki;Y. Miyoshi;Ralf Jaiser
基于1979-2015年期间的复合分析，我们描述了巴伦支-卡拉海重海冰年和轻海冰年之间观测到的弱极涡（WPV）事件期间向上行星尺度波传播的差异。在重冰年的WPV事件期间，向上波传播由波数1分量主导。相比之下，发生在轻冰年的WPV事件的特征是更强的波数2传播，这是由对流层波数2对巴伦支-卡拉海海冰减少的响应引起的。上述观测特征得到了大气环流模式试验的支持。因此，在目前的气候条件下，北极海冰损失是WPV事件期间调制波传播的一个可能因素。我们还发现，在轻冰年的WPV事件有更强的平流层-对流层耦合，其次是更冷的中纬度地面条件，特别是在欧亚大陆。
We characterize the differences in the upward planetary‐scale wave propagation during observed weak polar vortex (WPV) events between heavy‐ and light‐sea‐ice years in the Barents‐Kara Sea based on a composite analysis for the period of 1979–2015. Upward wave propagation during WPV events in heavy‐ice years is dominated by the wavenumber 1 component. In contrast, WPV events occurring in light‐ice years are characterized by stronger wavenumber 2 propagation, which is caused by the tropospheric wavenumber 2 response to sea‐ice reduction in the Barents‐Kara Sea. The above observed features are supported by an Atmospheric General Circulation Model experiment. Thus, under present climate conditions, Arctic sea‐ice loss is a possible factor modulating the wave propagation during the WPV events. We also find that the WPV events in light‐ice years have stronger stratosphere‐troposphere coupling, followed by colder midlatitude surface conditions particularly over Eurasia.