Upper-Ocean Circulation and Tropical Atlantic Interannual Modes

Abstract The impact of tropical Atlantic Ocean variability modes in the upper-ocean circulation has been investigated. For this purpose, we use three oceanic reanalyses, an interannual forced-ocean simulation, and satellite data for period 1982–2018. We have explored changes main surface subsurface ocean currents during emergence meridional mode (AMM), zonal (AZM), AMM–AZM connection. developing phase AMM is associated with a boreal spring intensification North Equatorial Countercurrent (NECC) reinforced summer Eastern Undercurrent (EEUC) north South Current (nSEC). During decaying phase, reduction wind forcing sea height gradient produces weakening circulation. connected AMM–AZM, addition to intensified NECC, EEUC, nSEC spring, anomalous north-equatorial curl excites Rossby wave (RW) that boundary-reflected into equatorial Kelvin (KW). KW reverses thermocline slope, EUC autumn, respectively. AZM, considerably reduced no consistent at levels. autumn upwelling RW-reflected mechanism activated, modifying pressure intensifies nSEC. NECC spring–summer. Our results reveal robust alteration AMM, highlighting decisive role waves connecting transport.