The impacts of the low level jets that form through the gaps in the topography in the Limpopo and Zambezi River Valleys (LRV and ZRV) on southern African climate are investigated. ERA-5 reanalysis data and numerical experiments using regional climate models reveal that the two valleys act as main gateways for southwest Indian Ocean-sourced moisture inflows into southern Africa. The effects of the LRV jet are stationary and mostly confined to south of Limpopo. By blocking the LRV, the moisture convergence in the interior of the subcontinent reduces and leads to a weakening in both the Angola Low and the ridging high over southeastern Africa. These are unfavorable conditions for the southward transport of moisture, causing a decrease of up to 50% of the subtropical southern African total summer rainfall. In contrast, the influence of the Zambezi jet varies with the season. During early austral summer, a blocked ZRV results in an overall deficit in rainfall in the subcontinent. It then leads to a weaker Mozambique Channel Trough, intensified Angola Low, hence increase in rainfall during January and February. Toward the end of the austral summer season, the absence of the Zambezi jet allows more moisture from the tropical Atlantic to penetrate into the mainland which then converges with moisture transported from the Indian Ocean and triggers excess rainfall over the tropical areas. These results have important implications for understanding the intraseasonal and interannual rainfall variability over the subcontinent during the summer half of the year.

研究了通过林波波河和赞比西河谷（LRV 和 ZRV）地形间隙形成的低空急流对南部非洲气候的影响。ERA-5 再分析数据和使用区域气候模型的数值实验表明，这两个山谷是印度洋西南部水分流入南部非洲的主要通道。LRV 射流的影响是静止的，主要限于林波波南部。通过阻断LRV，次大陆内部的水分汇聚减少并导致安哥拉低压和非洲东南部的脊高压减弱。这些都是水分向南输送的不利条件，导致南部非洲亚热带夏季总降雨量减少多达 50%。相比之下，赞比西喷气式飞机的影响因季节而异。在澳大利亚初夏，ZRV 受阻导致次大陆降雨量总体不足。然后导致莫桑比克海峡海槽减弱，安哥拉低压加剧，因此一月和二月降雨量增加。在南方夏季末期，赞比西急流的消失使更多来自热带大西洋的水分渗透到大陆，然后与从印度洋输送的水分会聚，并引发热带地区的过量降雨。这些结果对于了解次大陆夏季半年的季节内和年际降雨变化具有重要意义。ZRV 受阻导致次大陆降雨量总体不足。然后导致莫桑比克海峡海槽减弱，安哥拉低压加剧，因此一月和二月降雨量增加。在南方夏季末期，赞比西急流的消失使更多来自热带大西洋的水分渗透到大陆，然后与从印度洋输送的水分会聚，并引发热带地区的过量降雨。这些结果对于了解次大陆夏季半年的季节内和年际降雨变化具有重要意义。ZRV 受阻导致次大陆降雨量总体不足。然后导致莫桑比克海峡海槽减弱，安哥拉低压加剧，因此一月和二月降雨量增加。在南方夏季末期，赞比西急流的消失使更多来自热带大西洋的水分渗透到大陆，然后与从印度洋输送的水分会聚，并引发热带地区的过量降雨。这些结果对于了解次大陆夏季半年的季节内和年际降雨变化具有重要意义。赞比西急流的消失使得来自热带大西洋的更多水分渗透到大陆，然后与从印度洋输送的水分会聚，并在热带地区引发过多的降雨。这些结果对于了解次大陆夏季半年的季节内和年际降雨变化具有重要意义。赞比西急流的消失使得来自热带大西洋的更多水分渗透到大陆，然后与从印度洋输送的水分会聚，并在热带地区引发过多的降雨。这些结果对于了解次大陆夏季半年的季节内和年际降雨变化具有重要意义。