Fig. 6: Decomposition of the future ENSO-induced US precipitation changes into ENSO amplitude and environmental effects.

a–c The changes in (a) total ENSO effect, (b) ENSO amplitude effect, and (c) ENSO environmental effect on winter US precipitation (mm day⁻¹) in SPEAR-LENS. The total ENSO effect is defined as the difference between the regression coefficients of scaled future ENSO and historical ENSO. The ENSO amplitude effect is defined as the difference in regression coefficients of scaled future ENSO and non-scaled future ENSO. The environmental effect is defined as the difference between the regression coefficients of non-scaled future ENSO and historical ENSO (See Method section 2.4). The precipitation shown in (a–c) is above the 95% confidence level based on the two-tailed Student’s t-test.