Two contrasting tropical convection modes from the eastern Pacific to northern Africa that drive Eurasian teleconnections in boreal summer
Zhiwei Zhu, Liaoyuan Shao, Rui Lü, Wenjian Hua
Abstract
Eurasian teleconnections in boreal summer significantly influence regional climates and extremes, yet their dynamic origins remain largely unclear. Here, we revealed two critical modes of tropical convection that drive these Eurasian teleconnections in boreal summer. The first mode is characterized by suppressed convection in the equatorial eastern Pacific, coupled with enhanced convection extending from the equatorial Atlantic to northern Africa. In contrast, the second mode displays similar suppressed convection in the equatorial eastern Pacific, but features enhanced convection in the Gulf of Mexico and the equatorial Atlantic. These two modes result in markedly different atmospheric teleconnections, leading to distinct surface air temperature anomalies across the Eurasian continent. Both modes arise from the combined effects of sea surface temperature anomalies in the eastern Pacific and the North Atlantic/Indian Ocean. This study offers new insights into dynamics and seasonal predictions of boreal summer Eurasian climates.