caa a22 4500 605472807 CHVBK 20210128100340.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00382-015-2472-x doi (NATIONALLICENCE)springer-10.1007/s00382-015-2472-x ENSO and non-ENSO induced charging and discharging of the equatorial Pacific [Elektronische Daten] [Bruce Anderson, Renellys Perez] It is well established that variations in extratropical North Pacific wind stress fields can influence the state of the tropical Pacific 12-15months prior to the maturation of boreal winter El Niño/Southern Oscillation (ENSO) events. While most research has focused on accompanying variations in the North Pacific trade winds and underlying sea surface temperatures that subsequently shift equatorward via anomalous air-sea interactions—e.g. meridional mode dynamics—observational and numerical model analyses indicate empirical and dynamical links exist between these same trade-wind variations and concurrent changes in subsurface temperatures across the equatorial Pacific, which can also serve as a key initiator of ENSO events. This paper shows that within an observationally-constrained ocean reanalysis dataset this initiation mechanism—termed the trade-wind charging (TWC) mechanism—is induced by the second leading mode of boreal winter zonal wind stress variability over the tropical Pacific and operates separately from ENSO-induced recharge/discharge of the equatorial Pacific heat content. The paper then examines the characteristics and evolution of the ENSO and TWC modes. Results indicate that the oceanic evolution for both modes is consistent with wind stress induced vertically-integrated, meridional mass transport into and out of the equatorial Pacific—i.e. a charging and discharging of the equatorial Pacific—despite having distinctly different wind stress anomaly patterns. The process-based similarity between these two modes of tropical Pacific wind stress variability suggests that both can produce a charging/discharging of the equatorial Pacific, however one (the ENSO mode) represents part of the ENSO cycle itself and the other (the TWC mode) represents a separate forcing mechanism of that cycle. Springer-Verlag Berlin Heidelberg, 2015 ENSO nationallicence Tropical-extratropical interactions nationallicence Ocean reanalysis nationallicence Charging and discharging processes nationallicence ENSO precursors nationallicence Anderson Bruce Department of Earth and Environment, Boston University, 02215, Boston, MA, USA aut Perez Renellys Cooperative Institute of Marine and Atmospheric Studies, University of Miami, Miami, FL, USA aut Climate Dynamics Springer Berlin Heidelberg 45/9-10(2015-11-01), 2309-2327 0930-7575 45:9-10<2309 2015 45 382 https://doi.org/10.1007/s00382-015-2472-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-015-2472-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Anderson Bruce Department of Earth and Environment, Boston University, 02215, Boston, MA, USA aut NATIONALLICENCE 700 1- Perez Renellys Cooperative Institute of Marine and Atmospheric Studies, University of Miami, Miami, FL, USA aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/9-10(2015-11-01), 2309-2327 0930-7575 45:9-10<2309 2015 45 382