The South America Low-level Jet (SALLJ) is a climatological feature with a critical role in the spatiotemporal distribution of precipitation in South America. While previous studies have focused on the mechanisms and variability of the SALLJ in the central Andes (i.e., southeast Peru, Bolivia, and Paraguay), the occurrence of the low-level jet in the eastern slopes of the northern Andes (i.e., northeast Peru, Colombia, and Venezuela) and its linkages to the central region have not been previously explored. This study shows that the SALLJ in the northern branch exceeds 10 m s⁻¹ during September–February and the frequency can be as high as in the central region. Moreover, the SALLJ can occur simultaneously or separately in both regions. When the SALLJ is active only in the northern branch, wind speeds are very low from Bolivia towards southeast South America (SESA) and precipitation is significantly reduced (1–4 mm day⁻¹) from climatology. In contrast, precipitation increases over eastern Bolivia by 2–4 mm day⁻¹. Composites suggest that the SALLJ northern branch is forced by a large-scale circulation pattern with the enhancement of the North Atlantic Subtropical High driving northeasterly winds over the northern Andes. Further analysis shows that the frequency and intensity of the SALLJ in the northern Andes has substantially increased in the last 39 years.

南美低空急流（SALLJ）是一种气候特征，在南美降水的时空分布中起着至关重要的作用。尽管先前的研究集中在安第斯山脉中部（即秘鲁东南部，玻利维亚和巴拉圭）SALLJ的机制和变异性，但低空急流在安第斯山脉北部（即秘鲁东北部）的东部斜坡上发生，哥伦比亚和委内瑞拉）及其与中部地区的联系。这项研究表明，北部分支的SALLJ超过10 m s ^-1在9月至2月期间，频率可能与中部地区一样高。此外，SALLJ可以在两个区域同时或分别发生。当SALLJ仅在北部分支处于活动状态时，从玻利维亚到南美东南部（SESA）的风速非常低，并且气候条件使降水显着减少（1-4天^{-1 -1}）。相比之下，玻利维亚东部的降水量增加了2-4 mm day ^-1。综合资料表明，随着北大西洋亚热带高压带动安第斯山脉北部的东北风的增强，SALLJ北部分支受到了大规模环流模式的推动。进一步的分析表明，在过去39年中，安第斯山脉北部SALLJ的频率和强度大大增加。