Response of the ITCZ to Northern Hemisphere cooling
Response of the ITCZ to Northern Hemisphere cooling
复制标题
DOI：
10.1029/2005gl024546
复制
发表时间：
2006-01-10
影响因子：
5.2
通讯作者：
Stouffer, RJ
中科院分区：
文献类型：
--
作者：
Broccoli, AJ;Dahl, KA;Stouffer, RJ
气候模拟，使用不同程度的复杂性模式，表明南北位置的热带辐合带（ITCZ）的半球间温度对比度的变化作出反应。各种时间尺度的古气候数据表明了类似的行为，ITCZ向南位移，以及北方半球寒冷时期热带大气环流的相关变化。为了确定一种机制，ITCZ位移可以被迫从热带外，我们使用一个气候模式与理想化的地理和一个简单的板状海洋。我们冷却的北方热带外和温暖的南部热带外，代表不对称的温度变化与冰期间冰期和千年尺度的气候变率。随着信风的变化和哈德利环流的不对称响应，ITCZ发生了沿着的南移。热带和中纬度地区之间的大气热交换的变化是这种响应的可能原因，这表明这种机制可能发挥重要作用，在ITCZ位移的时间尺度从十年到冰期-间冰期。
Climate simulations, using models with different levels of complexity, indicate that the north-south position of the intertropical convergence zone (ITCZ) responds to changes in interhemispheric temperature contrast. Paleoclimate data on a variety of timescales suggest a similar behavior, with southward displacements of the ITCZ and associated changes in tropical atmospheric circulation during cold periods in the Northern Hemisphere. To identify a mechanism by which ITCZ displacements can be forced from the extratropics, we use a climate model with idealized geography and a simple slab ocean. We cool the northern extratropics and warm the southern extratropics to represent the asymmetric temperature changes associated with glacial-interglacial and millennial-scale climate variability. A southward shift in the ITCZ occurs, along with changes in the trade winds and an asymmetric response of the Hadley circulation. Changes in atmospheric heat exchange between the tropics and midlatitudes are the likely cause of this response, suggesting that this mechanism may play an important role in ITCZ displacements on timescales from decadal to glacial-interglacial.