Fig. 1: Time series of HCE latitude and spatial structure of Hadley cell expansion.

a Time series of the DJFM-mean HCE latitude (°N) for the period 1979 to 2019. b Mass streamfunction for climatology (contour) and high-minus-low HCE latitude year composite (shading) for DJFM. Units are 1010 kg s−1. Stippling denotes a significant area at the 95% confidence level.