The Hadley cell response to globally increasing CO₂ concentrations is spatially complex, with an intensified rising branch and weakened descending branch. To better understand these changes, we examine the sensitivity of the Hadley cell to idealized radiative forcing in different latitude bands. The Hadley cell response is, to first order, governed by the latitudinal structure of the forcing. The strengthening of the upward branch is attributed to tropical forcing, whereas the weakening of the descending branch is attributed to extratropical forcing. These direct radiatively-forced Hadley cell responses are amplified by changes in atmospheric eddy heat transport while being partially offset by changes in gross moist stability and ocean heat uptake. The radiative feedbacks further modulate the Hadley cell response by altering the meridional atmospheric energy gradient. The Hadley cell projections under global warming are thus a result of opposing – and thus compensating – effects from tropical and extratropical radiative forcings.

Hadley 细胞对全球增加的 CO _2的反应浓度在空间上是复杂的，上升分支增强，下降分支减弱。为了更好地理解这些变化，我们检查了哈德利单元对不同纬度波段理想化辐射强迫的敏感性。哈德利细胞反应首先受强迫的纬度结构支配。上行分支的加强归因于热带强迫，而下行分支的减弱归因于温带强迫。这些直接的辐射强迫哈德利细胞反应被大气涡流热传输的变化放大，同时被总湿稳定性和海洋热吸收的变化部分抵消。辐射反馈通过改变经向大气能量梯度进一步调节哈德利细胞响应。