Fig. 4: Thresholds of the identified key factors and their implication for ENSO prediction.
From: Single- and multi-year ENSO events controlled by pantropical climate interactions
a, b Relative percentages of the single (black bar-chart) and multi (red bar-chart)-year El Niños in the CESM1 with their key factors of developing-season intensity changing from 2.2 to 0.2 °C and zonal maximum location changing from 3.3 to −0.1 °C. c, d Same as a, b except for single (black bar-chart) and multi (blue bar-chart)-year La Niñas with their key factors of pre-onset Pacific condition changing from 3.9 to −0.4 °C and zonal maximum location changing from −1.0 to 0.8 °C. The green and purple horizontal lines in a–d mark a 50% relative percentage for identifying thresholds from the key factors. e, f Scatter plots of the zonal maximum location against the developing-season intensity for the single (black dots) and multi (red dots)-year El Niños in the CESM1 and observations. The numbers of single- and multi-year El Niños in the four regimes separated by two thresholds (two green lines) are, respectively, shown as black and red text in the legend with larger numbers in bold. g, h Same as e, f except they display the zonal maximum location against the pre-onset Pacific condition for single (black dots) and multi (blue dots)-year La Niñas with the two regimes separated by one threshold (one purple line). Gray shadings in e–h indicate regimes where the major ENSO group (single-year event for El Niño or multi-year event for La Niña) is dominant.
