This study highlights the influence of convectively coupled Kelvin wave (KW) activity on deep convection and African easterly waves (AEWs) over North Africa during dry and wet boreal summer rainfall years. Composite analysis based on 25 years of rainfall, satellite observed cold cloud temperature, and reanalysis data sets show that KWs are more frequent and stronger in dry Central African years compared with wet years. Deep convection associated with KWs is slightly more amplified in dry years compared with wet years. Further, KW activity over North Africa strengthens the lower level zonal flow and deepens the zonal moisture flux in dry years compared with wet years. Results also show that enhanced KW convection is in phase with above-average AEW variance in dry years. However, enhanced KW convection is out-of-phase with average AEW activity in wet years. In general, this study suggests that KW passage over Africa enhances convective activity and more strongly modulates the monsoon flow and moisture flux during the dry years than wet years.

中文翻译：

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非洲干旱和潮湿的夏季降雨年中开尔文波活动的影响

这项研究强调了北旱夏季干湿降雨年中，对流耦合开尔文波（KW）活动对北非深对流和非洲东风（AEW）的影响。基于25年降雨，卫星观测到的冷云温度和再分析数据集的综合分析表明，与湿润年份相比，中非干旱年份的KWs更为频繁且较强。与湿润年份相比，在干旱年份，与KWs有关的深对流会稍微放大。此外，与湿润年份相比，干燥年份的北非KW活动增强了较低水平的纬向气流，并加深了纬向湿度。结果还表明，在干旱年份，KW对流增强与AEW的变化高于平均水平。然而，增强的KW对流与湿年中的平均AEW活动不同相。总体而言，这项研究表明，在干旱年份比在湿润年份，KW在非洲的通过增强了对流活动，并更强烈地调节了季风流量和水分通量。