Purpose of Review

This review focuses on recent progress in understanding the extratropical influence on the annual- and zonal-mean intertropical convergence zone (ITCZ) position using a hierarchy of model simulations and theory.

Recent Findings

Significant progress in our theoretical understanding of the zonal-mean ITCZ position has been made utilizing simulations with a slab ocean. Interhemispheric contrasts in the atmospheric heating (e.g., via an anomalous radiative forcing in one hemisphere) lead to a compensating cross-equatorial energy transport by Hadley circulation adjustments and corresponding meridional ITCZ shifts. In particular, high-latitude radiative perturbations have a strong influence on the ITCZ position. The effectiveness of extratropical forcing for resulting in ITCZ shifts is amplified by cloud radiative feedbacks in the midlatitudes and tropical water vapor feedback associated with the ITCZ displacement. However, more recently conducted fully coupled model simulations tend to show a less pronounced extratropical influence on the ITCZ position due to additional compensating effects from ocean dynamics. The oceanic damping effect on ITCZ shifts results from distinct ocean circulation components, including the Atlantic Meridional Overturning Circulation and the wind-driven subtropical cell. Both the relative importance of different ocean circulation components and the roles of different radiative feedbacks are sensitive to forcing location, making the tropical hydroclimate response to extratropical forcing sensitive to the geographical location of the forcing, for instance, in which ocean basin it occurs. The interaction between radiative feedbacks and ocean dynamical adjustment further confounds the determination of extratropical influence on the ITCZ position, which has motivated a recently initiated model intercomparison project.

Summary

The zonal-mean energetics framework needs to be refined to explain beyond the time- and zonal-mean ITCZ position so as to incorporate transient propagation features and the spatial distribution of the tropical precipitation response.

中文翻译：

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温带对热带降雨分布的影响

审查目的

本综述重点介绍了利用模型模拟和理论层次结构了解温带对年平均和纬向平均热带辐合带（ITCZ）位置影响的最新进展。

最近的发现

利用板状海洋的模拟，我们对纬向平均 ITCZ 位置的理论理解取得了重大进展。大气加热的半球间对比（例如，通过一个半球的异常辐射强迫）导致通过哈德利环流调整和相应的经向 ITCZ 移动补偿跨赤道能量传输。特别是高纬度辐射扰动对 ITCZ 位置有很大影响。中纬度地区的云辐射反馈和与 ITCZ 位移相关的热带水汽反馈放大了温带强迫导致 ITCZ 移动的有效性。然而，由于海洋动力学的额外补偿效应，最近进行的全耦合模型模拟往往显示出对 ITCZ 位置的温带影响不太明显。 ITCZ 变化的海洋阻尼效应是由不同的海洋环流成分造成的，包括大西洋经向翻转环流和风驱动的副热带环流。不同海洋环流成分的相对重要性和不同辐射反馈的作用都对强迫位置敏感，使得热带水气候对温带强迫的响应对强迫的地理位置（例如发生在哪个洋盆）敏感。辐射反馈和海洋动力调整之间的相互作用进一步混淆了温带对 ITCZ 位置影响的确定，这激发了最近启动的模型比对项目。

概括

需要完善纬向平均能量学框架，以解释时间和纬向平均 ITCZ 位置之外的情况，以便纳入瞬态传播特征和热带降水响应的空间分布。