A model intercomparison of the tropical precipitation response to a CO2 doubling in aquaplanet simulations
A model intercomparison of the tropical precipitation response to a CO2 doubling in aquaplanet simulations
复制标题
水行星模拟中热带降水对二氧化碳加倍响应的模型比较
DOI：
10.1002/2016gl072347
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发表时间：
2017
影响因子：
5.2
通讯作者：
T. Merlis
中科院分区：
文献类型：
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作者：
Jeongbin Seo;Sarah M. Kang;T. Merlis
在今天的气候中，平均热带辐合区(ITCZ)位于赤道以北。我们研究了全球变暖下ITCZ纬度的变化，使用了与水行星板块海洋耦合的多个大气模型。参考气候因规定的海洋升温而变暖，但二氧化碳增加了一倍，对此感到不安。大多数模式显示ITCZ向北移动，但这种移动不能用大气能量输送(FA)消失的赤道能量通量响应来解释。模拟的环流位移的能量学是微妙的：哈德利环流输送能量的效率，总湿稳定度(Δm)的变化，在确定δFA时，主导着质量通量的变化。即使当δFA ≈ 0时，由于Δm的变化，ITCZ也会显著移动，这在以前常常被忽略。ITCZ响应对δΔm的依赖性要求我们更好地理解决定热带Δm的物理机制。
In the present‐day climate, the mean Intertropical Convergence Zone (ITCZ) is north of the equator. We investigate changes in the ITCZ latitude under global warming, using multiple atmospheric models coupled to an aquaplanet slab ocean. The reference climate, with a warmer north from prescribed ocean heating, is perturbed by doubling CO2. Most models exhibit a northward ITCZ shift, but the shift cannot be accounted for by the response of energy flux equator where the atmospheric energy transport (FA) vanishes. The energetics of the simulated circulation shifts are subtle: changes in the efficiency with which the Hadley circulation transports energy, the total gross moist stability (Δm), dominate over mass flux changes in determining δFA. Even when δFA ≈ 0, the ITCZ can shift significantly due to changes in Δm, which have often been neglected previously. The dependence of ITCZ responses on δΔm calls for improved understanding of the physics determining the tropical Δm.