Extended Data Fig. 5: Schematic of ocean-atmosphere dynamics during positive and negative AMO/AMM states.
From: Equatorial upwelling of phosphorus drives Atlantic N2 fixation and Sargassum blooms
Schematic overview of the ITCZ position, the Saharan dust plume, and surface currents during positive (top) and negative (bottom) AMO/Atlantic Meridional Mode (AMM) phases. Positive AMO/AMM phases correspond to a northward displacement of the ITCZ, a predominance of the Saharan dust plume over the subtropical North Atlantic and Caribbean, reduced easterly wind strength, and an enhanced North Equatorial Counter Current (NECC). Negative AMO/AMM phases correspond to a southward displacement of the ITCZ, a predominance of Saharan dust over the equatorial North Atlantic and Amazon basin, and stronger easterlies that enhance equatorial upwelling. Also, during negative AMO/AMM phases the North Equatorial Current (NEC), the South Equatorial Current (SEC) and the Caribbean Current (CC) are stronger and transport more Atlantic water with excess P into the Caribbean, ultimately enhancing N2 fixation. Base map: ‘Blue Marble’ global mosaic. Credit: NASA’s Goddard Space Flight Center.
