Robust Longitudinally Variable Responses of the ITCZ to a Myriad of Climate Forcings
Robust Longitudinally Variable Responses of the ITCZ to a Myriad of Climate Forcings
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DOI：
10.1029/2020gl088833
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发表时间：
2020-09-16
影响因子：
5.2
通讯作者：
Pausata, Francesco S. R.
中科院分区：
文献类型：
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作者：
Atwood, Alyssa R.;Donohoe, Aaron;Pausata, Francesco S. R.
我们使用一大套耦合气候模式模拟来评估热带雨带经向位移对自然和人为强迫的响应的经向变化。我们发现，无论强迫的特征如何，纬向平均Hadley环流的能量框架一般不适用于描述区域尺度上的雨带移动。具有较大半球不对称性的强迫，如温带火山强迫、融水强迫和末次冰期最大，导致雨带强烈的纬向平均位移；然而，位移的方向和大小随着经度的变化而强烈变化。即使太平洋雨带在任何强迫作用下也不是均匀移动的。具有弱半球不对称性的强迫，如CO(2)和中全新世强迫，会产生小的或不存在的纬向平均移位，但雨带确实以连贯的方式跨模式发生区域移位，这可能会产生重要的动力学后果。
We evaluate the longitudinal variation in meridional shifts of the tropical rainbelt in response to natural and anthropogenic forcings using a large suite of coupled climate model simulations. We find that the energetic framework of the zonal mean Hadley cell is generally not useful for characterizing shifts of the rainbelt at regional scales, regardless of the characteristics of the forcing. Forcings with large hemispheric asymmetry such as extratropical volcanic forcing, meltwater forcing, and the Last Glacial Maximum give rise to robust zonal mean shifts of the rainbelt; however, the direction and magnitude of the shift vary strongly as a function of longitude. Even the Pacific rainband does not shift uniformly under any forcing considered. Forcings with weak hemispheric asymmetry such as CO(2)and mid-Holocene forcing give rise to zonal mean shifts that are small or absent, but the rainbelt does shift regionally in coherent ways across models that may have important dynamical consequences.