Figure 2.

(a) Schematic that describes how inter‐hemispheric extratropical thermal forcing is balanced by the adjustment of the Hadley circulation. Suppose the northern (southern) extratropics are warmed (cooled). The faded (dark) gray contours in the upper panel indicate the Hadley circulation in the reference (perturbed) state. The Hadley circulation transports moisture equatorward following its lower branch (blue arrow) and transports energy poleward following its upper branch (red arrow). (Reprinted with permission from Kang, Shin, and Xie (2018). Copyright 2018 Nature; under the creative commons license http://creativecommons.org/licenses/by/4.0/). (b) Temperature contrast between Northern and Southern hemisphere extratropics (poleward of 24°N and 24°S) based on instrumental data (black), and average daily rainfall over the Sahel (12°−18°N, 20°W–35°E) during June–October based on land station data (blue). All temperatures and temperature contrasts are given as anomalies relative to the 1960–1991 AD mean (Reprinted from Schneider, Bischoff, and Haug (2014). Copyright 2014 Springer‐Nature)