Abstract
El Niņo/Southern Oscillation (ENSO) events are known to force atmospheric teleconnections
that impact extratropical sea surface temperatures and surface winds. In this paper we use
focused model experiments to investigate whether this extratropical variability can feedback to,
and significantly impact, the Tropics through ocean Rossby waves. We use an atmospheric general
circulation model coupled to a reduced gravity Pacific Ocean model to isolate these potential
feedback loops and quantify their impact on ENSO variability. We find that anomalous winds and
heat fluxes located in regions of maximum mean subduction in the subtropical North Pacific
trigger ocean Rossby waves that take approximately four years to reach the equator.
Most notably, we demonstrate that this feedback loop causes a primarily 2-year ENSO,
when only the Tropics is coupled, to shift to a more realistic broad 2-5 year range by
damping ~2 year variability and amplifying ~4 year variability.