Fig. 7: Observed and simulated changes in Southern Annual Mode and Interdecadal Pacific Oscillation indices.
From: Simulated Antarctic sea ice expansion reconciles climate model with observation
a The December-January-February (DJF) Southern Annual Mode (SAM) index over 1979–2014 based on HadSLP2 (gray), ERA5 (green), station-based data by Marshall (purple), HIST_ASI+ (ensemble mean, red; ensemble spread, light red), and HIST_ASI- (ensemble mean, blue; ensemble spread, light blue) where the ensemble spread is calculated as one standard deviation among ensembles. b Linear trends of the DJF SAM index over 1979–2014 for the same data, using the same color scheme, with dots representing ensemble mean and bars representing ensemble spread for either HIST_ASI+ or HIST_ASI-. c The TPI index over 1979-2014 based on COBESSTv2 (gray), ERSSTv5 (purple), HadISST (green), HIST_ASI+ (ensemble mean, red; ensemble spread, light red), and HIST_ASI- (ensemble mean, blue; ensemble spread, light blue). The ensemble spread in HIST_ASI+ or HIST_ASI- is calculated as one standard deviation among ensembles. A 13-year Lanczos filtering has been applied for all the Interdecadal Pacific Oscillation (IPO) timeseries.
