What kind of stratospheric sudden warming propagates to the troposphere?
What kind of stratospheric sudden warming propagates to the troposphere?
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DOI：
10.1029/2005gl024784
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发表时间：
2006-02
影响因子：
5.2
通讯作者：
Kentaro Nakagawa;K. Yamazaki
中科院分区：
文献类型：
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作者：
Kentaro Nakagawa;K. Yamazaki
通过对欧洲中期天气预报中心45年再分析资料的合成分析，研究了平流层突然变暖（SSW）事件向下传播到对流层的影响因素。在SSW的增长阶段，传播到对流层的事件表现出增强的波数2波的向上通量，而不向下传播的事件显示减少的波数2通量。在这两个事件中，波数为1的波的向上通量增强，但在非传播事件中增强更强。传播事件的合成揭示了在增长阶段对流层水平位势异常的负欧亚模式，以及事件之后的负北极涛动模式，而非传播事件之前是正欧亚模式。在这两类事件中，对流层异常主要是由对流层行星波强迫产生的SSW出现之前。
The factors affecting the downward propagation of stratospheric sudden warming (SSW) events to the troposphere are studied through composite analysis of 45‐year reanalysis data from the European Centre for Medium‐Range Weather Forecasts. During the growth stage of SSW, events that propagate into the troposphere exhibit enhanced upward flux of the wavenumber 2 wave, while events that do not propagate downward display reduced wavenumber 2 flux. In both events, upward flux of the wavenumber‐1 wave is enhanced, but the enhancement is stronger in the non‐propagating event. The composite for propagating events reveals a negative Eurasian pattern of horizontal geopotential anomalies in the troposphere during the growth stage, and a negative Arctic Oscillation pattern following the event, while non‐propagating events are preceded by a positive Eurasian pattern. In both types of event, the tropospheric anomalies are generated mainly by tropospheric planetary wave forcing prior to the emergence of SSW.