Picture: Atlantic Ocean. Credit: Aaron Ulsh (Pexels)

The El Nino Southern Oscillation (ENSO) is known to affect sea surface temperature in the tropical North Atlantic via atmospheric teleconnections in the tropics and the extra-tropics. However, this influence seems to vary depending on the strength of ENSO.

In this study, CLEX researchers and colleagues showed that the North Atlantic sea-surface temperature response to ENSO is nonlinear with respect to the strength of the sea-surface temperature forcing in the tropical Pacific. For example, further increases in El Nino magnitudes ceases to create further increases of the tropical North Atlantic sea surface temperature anomaly.

They also found that the tropical teleconnection pathway is more linear than the extratropical pathway.

Paper: Casselman, Jake W., Andréa S. Taschetto, and Daniela I.V. Domeisen. ” Non-linearity in the pathway of El Niño-Southern Oscillation to the tropical North Atlantic”, Journal of Climate (published online ahead of print 2021), https://doi.org/10.1175/JCLI-D-20-0952.1