Equatorial Rossby waves on cold surge days and their impact on rainfall
Equatorial Rossby waves on cold surge days and their impact on rainfall
复制标题
寒潮日的赤道罗斯贝波及其对降雨的影响
DOI：
10.1002/qj.4493
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发表时间：
2023
影响因子：
8.9
通讯作者：
Diong J
中科院分区：
文献类型：
--
作者：
Diong J
通过研究活跃赤道Rossby（R1）波的不同涡度位相和与R1波相关的南海（SCS）的动力学，了解决定冷涌（CS）期间赤道南海（SCS）及其周边区域降水分布的过程。CS可以被认为是来自中纬度的反气旋外流，表现得像一组分散的R1涡旋模。结果表明，R1波的涡度在冷CS轴的西侧有反气旋相，而在冷CS轴的东侧有气旋相。南海赤道区的CS风在气旋性活跃期比反气旋性活跃期出现早、持续时间长、纬向分量大。在气旋性涡度活跃阶段，赤道南海的降水异常型由“钩状”型转变为“V型”型，这是波向西传播的结果。在气旋性涡度中心附近，降水概率增大，而在反气旋性涡度中心南部，降水概率增大。有增加（减少）的强度和概率的极端降雨事件在活跃的气旋（反气旋）涡度阶段的CS天。总体而言，降水异常主要是由雨日强度的变化而不是雨日数的变化所主导。这些变化反映了R1波涡度位相在CS日降水分布中的作用。增强和抑制降雨的时间将提供额外的有价值的信息，以帮助改善极端天气事件的预报。
This study aims to understand the process that determines the regional rainfall distribution in the equatorial South China Sea (SCS) and its surrounding during the cold surge (CS) days by looking at the different vorticity phases of active equatorial Rossby (R1) waves and the dynamics of the CSs related to the R1 wave. The CS can be thought of as an anticyclonic outflow from midlatitude and behaves like a dispersive group of R1 meridional modes. From the study, it shows the vorticity of the R1 wave arranges itself in such a way that the anticyclonic phase is located to the west and the cyclonic phase is located to the east of the cold CS axis. The CS winds in the equatorial SCS occur early, remain longer, and possess a larger zonal component in the active cyclonic phase compared with the active anticyclonic phase. During the active cyclonic vorticity phase, the rainfall anomalies pattern in the equatorial SCS changes from a “tick‐mark‐like” pattern to a “V‐shape” pattern as a consequence of the westward propagation of the wave. The probability of rainfall increases near the centre of cyclonic vorticity, but for anticyclonic vorticity the probability increases in the southern part of the vorticity centre. There is both increased (decreased) intensity and probability of extreme rainfall events during the active cyclonic (anticyclonic) vorticity phase on CS days. Overall, the rainfall anomalies are largely dominated by changes in the intensity on wet days rather than the number of wet days. These changes indicate the roles of the R1 wave vorticity phase in the rainfall distribution during CS days. The timing of enhancement and suppression of rain will provide additional valuable information to help improve forecast extreme weather events.
影响因子：
3.1
作者：
Yang G
通讯作者：
Yang G
冬季 MONEX：四分之一世纪及以后
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
Richard H. Johnson;Chih
通讯作者：
Chih
影响因子：
3.2
作者：
WU, MC;CHAN, JCL
通讯作者：
CHAN, JCL