Fig. 5

Tropical precipitation regressed onto Niño3.4 SST index during boreal winter (mm⁻¹d⁻¹ °C⁻¹). Color-mapping and contour show the regression coefficients of precipitation and SST onto Niño 3.4 index in a GPCP, b reanalysis datasets, c AMIP5 models, d AMIP6 models, e CMIP5 models and f CMIP6 models. g That regression coefficients of the precipitation gradient (defined as the difference of the spatial-mean precipitation between the “cold tongue” region 5° S–5° N, 165° E–135° W and the ‘‘warm pool’’ region 10° S–10° N, 95° E–145° E. These two regions are marked as black boxes in Fig. 5a onto the Niño3.4 SST index in reanalyses and AMIP/CMIP models. The white lines show the regression coefficients, and the ranges of the bars indicate the 95% confidence interval of these regression results with Student’s t test. Panel h is the box–whisker plots to indicate the spread of the reanalysis and model representation