Since 2011, huge amounts of Sargassum algae are detected in the equatorial Atlantic, causing large strandings events on the coasts of the West Indies, Brazil and West Africa. The distribution of this stock shows strong annual and interannual variability, whose drivers are not settled yet. Here we use satellite Sargassum observations from MODIS and currents from an ocean reanalysis to simulate the passive transport of algae in 2017. Wind effect was necessary to fit the observed distribution. Simulations reasonably reproduce the satellite monthly distribution for up to seven months, confirming the prominent role of transport in the distribution cycle. Annual cycle appears as a zonal exchange between eastern (EAR) and western accumulation regions (WAR). EAR is well explained by advection alone, with sharp meridional distribution controlled by converging currents below the inter-tropical Convergence Zone. Instead, WAR is not explained by advection alone, suggesting local growth.

自2011年以来，在赤道大西洋中发现了大量的Sargassum藻类，在西印度群岛，巴西和西非的沿海地区造成了大的搁浅事件。该股票的分布显示出强大的年度和年度间可变性，其动因尚未确定。在这里我们使用卫星Sargassum来自MODIS的观测数据以及来自海洋再分析的水流，以模拟2017年藻类的被动运输。必须使用风效应来适应观测到的分布。模拟合理地再现了长达七个月的卫星每月分布，证实了运输在分布周期中的重要作用。年度周期表现为东部（EAR）与西部堆积区（WAR）之间的区域交换。仅通过对流就可以很好地解释EAR，通过在热带收敛带以下的会聚电流控制清晰的子午线分布。取而代之的是，WAR不能仅通过对流来解释，这暗示了局部增长。