Fig. 5: Distributions of standard deviation of SST anomalies (∘C) along the equator (averaged between 2°S and 2°N).
From: Upper-ocean stratification changes control ENSO amplitude shift under sustained global warming
They are calculated from intermediate coupled model (ICM) experiments for three periods of 1940-1990 (P1), 2040-2090 (P2) and 2240-2290 (P3), respectively. a ICM-P1 and ICM-P2 are control experiments (solid lines), in which three components of the mean ocean state during one period are correspondingly used for the same period; then, focusing on the control experiment during P1 (ICM-P1), one of its three mean component is replaced by the corresponding one during P2 (dashed or dotted lines): ICM-P1P2-N2 is an experiment in which the stratification component (N2) during P1 is replaced by the one during P2; the similar denotations are for ICM-P1P2-U (the surface velocity_SST component in ICM-P1 (denoted as U) is replaced by the one during P2) and ICM-P1P2-Te (the thermocline component (Te) in ICM-P1 is replaced by the one during P2), respectively. b The same as (a), but with ICM-P2 and ICM-P3 being the control experiments, in which sensitivity experiments are performed. Focusing on the ICM-P2 control experiment: one of its three mean components during P2 is replaced by the corresponding one during P3 (dashed or dotted lines): ICM-P2P3-N2 is a sensitivity experiment in which the stratification component during P2 (denoted as N2) is replaced by that during P3; the similar denotations are for ICM-P2P3-U and ICM-P2P3-Te, respectively. c The same as (b), with mode-specific sensitivity experiments performed based on ICM-P2, in which only p₁ or p₂ for the stratification component is replaced by corresponding one from P3 (dashed or dotted lines): ICM-P2P3-N2 mode1+2 is a sensitivity experiment in which the stratification parameters for mode 1 (p1) and mode 2 (p2) during P2 are both replaced by those during P3; this experiment is similar to that shown in b (ICM-P2P3-N2). Then, parameters for mode 1 (p1) or mode 2 (p2) in ICM-P2 are individually replaced by those during P3. ICM-P2P3-N2 mode1 is a sensitivity experiment in which only mode 1 (p1) is replaced by the corresponding one during P3; ICM-P2P3-N2 mode2 is an experiment in which only p2 is replaced, disentangling the stratification effects on ENSO attributed to different baroclinic modes.
