Disproving the Bodélé depression as the primary source of dust fertilizing the Amazon Rainforest

Motivated by the ongoing debates about the relative contribution of specific North African dust sources to the trans-Atlantic dust transport to the Amazon Basin, the current study integrates a suite of satellite observations into a novel trajectory analysis framework to investigate dust transport from the leading two North African dust sources, namely the Bodélé depression and El Djouf. In particular, this approach provides observation-constrained quantification of the dust’s dry and wet deposition along its transport pathways and is validated against multiple satellite observations. The current large ensemble trajectory simulations identify favorable transport pathways from the El Djouf across the Atlantic Ocean with respect to seasonal rain belts. The limited potential for long-range transport of dust from the Bodélé depression is attributed to the currently identified extensive near-source dust removal primarily by dry and wet deposition during boreal winter and summer, respectively.

鉴于当前关于北非特定沙尘源对跨大西洋沙尘输送至亚马逊盆地的相对贡献的持续争论，本研究将一系列卫星观测数据整合到一个新颖的轨迹分析框架中，以探究来自北非两大主要沙尘源——即博德莱洼地（Bodélé depression）和埃尔朱夫（El Djouf）的沙尘输送过程。具体而言，该方法可对沙尘输送路径上的干湿沉降进行观测约束下的量化分析，并通过多源卫星观测数据验证。当前的大集合轨迹模拟结果表明，埃尔朱夫沙尘穿越大西洋的输送路径与季节性雨带分布具有良好的匹配性。博德莱洼地沙尘的长距离输送潜力有限，这主要归因于本研究识别出的近源沙尘移除过程——即北半球冬季以干沉降为主，夏季以湿沉降为主。