Teleconnection patterns of different El Ni\~no types revealed by climate network curvature

TL;DR

This study uses climate network curvature to differentiate the teleconnection patterns of Eastern Pacific and Central Pacific El Niño types, revealing distinct regional influence pathways and emphasizing the eastern Pacific's mediating role.

Contribution

It introduces a novel application of Forman-Ricci curvature to climate networks, providing a global perspective on how different El Niño types influence teleconnection patterns.

Findings

EP events show tropical teleconnections; CP events involve tropical-extratropical links.

The eastern Pacific mediates most remote influences for both El Niño types.

Central Pacific region has few teleconnections, even during CP events.

Abstract

The diversity of El Ni\~no events is commonly described by two distinct flavors, the Eastern Pacific (EP) and Central Pacific (CP) types. While the remote impacts, i.e. teleconnections, of EP and CP events have been studied for different regions individually, a global picture of their teleconnection patterns is still lacking. Here, we use Forman-Ricci curvature applied on climate networks constructed from 2-meter air temperature data to distinguish regional links from teleconnections. Our results confirm that teleconnection patterns are strongly influenced by the El Ni\~no type. EP events have primarily tropical teleconnections whereas CP events involve tropical-extratropical connections, particularly in the Pacific. Moreover, the central Pacific region does not have many teleconnections, even during CP events. It is mainly the eastern Pacific that mediates the remote influences for both El Ni\~no types.