Galapagos Regional Nino Index

The Galapagos Regional Nino Index (GReNI) is a local sea surface temperature index designed to represent ocean conditions in and around the Galapagos Archipelago.

Why a local index is useful

Standard basin-scale ENSO indices such as Nino 3.4 describe large-scale Pacific variability well, but they do not always capture the SST anomalies most relevant to island-scale rainfall in the Galapagos. A local index can therefore be more directly tied to mesoscale atmospheric response.

Research use

Schneider et al. (2025, Geophysical Research Letters) used GReNI to show that local SST anomalies are a stronger diagnostic for heavy rainfall events in the Galapagos than basin-scale ENSO indices alone.

See also: Sea surface temperature, Galapagos Cold Pool, Heavy rainfall in the Galapagos