Modulation in Teleconnections of the El Nino Southern Oscillation by Atlantic Multidecadal Sea Surface Temperature Variability

Abstract

This manuscript uses idealized AGCM experiments to explore impacts of observed decadal Atlantic sea surface temperature (SST) changes on El Nino Southern Oscillation teleconnections. Significant regional changes are observed in numerous locations (e.g., Indo-Pacific and Central Africa) due to the addition of the AMV anomalies. In some regions the teleconnection impacts of AMV forcing appeared to scale with the magnitude of the AMV forcing. However, the AMV induced modulation of temperature and precipitation teleconnections is regionally specific with changes in magnitude, statistical strength, and spatial connection dependent on region. These ENSO teleconnection changes were found to be asymmetric between AMV phases, with negative anomalies appearing to have a larger effect. We hypothesize these changes may be underpinned by a AMV induced modulation and migration of ENSO's equatorial precipitation response.