Nino indices, North Atlantic Oscillation (NAO), Souther Oscillation Index (SOI)


The goal of this diagnostic is to compute indices based on area averages.

In recipe_combined_indices.yml, after defining the period (historical or future projection), the variable is selected. The predefined areas are:

  • Nino 3

  • Nino 3.4

  • Nino 4

  • North Atlantic Oscillation (NAO)

  • Southern Oscillation Index (SOI)

Available recipes and diagnostics

Recipes are stored in recipes/

  • recipe_combined_indices.yml

Diagnostics are stored in diag_scripts/magic_bsc/

  • combined_indices.R : calculates the area-weighted means and multi-model means, with or without weights

User settings

User setting files are stored in recipes/

  1. recipe_combined_indices.yml

Required settings for script

  • region: one of the following strings Nino3, Nino3.4, Nino4, NAO, SOI

  • running_mean: an integer specifying the length of the window (in months) to be used for computing the running mean.

  • moninf: an integer can be given to determine the first month of the seasonal mean to be computed (from 1 to 12, corresponding to January to December respectively).

  • monsup: an integer specifying the last month to be computed (from 1 to 12, corresponding to January to December respectively).

  • standardized: ‘true’ or ‘false’ to specify whether to compute the standarization of the variable.

    Required settings for preprocessor (only for 3D variables)


  • levels: [50000] # e.g. for 500 hPa level

  • scheme: nearest


  • all variables (atmos/ocean, monthly, longitude, latitude, time)

Observations and reformat scripts



Example plots


Time series of the standardized sea surface temperature (tos) area averaged over the Nino 3.4 region during the boreal winter (December-January-February). The time series correspond to the MPI-ESM-MR (red) and BCC-CSM1-1 (blue) models and their mean (black) during the period 1950-2005 for the ensemble r1p1i1 of the historical simulations.