Seasonal Cycle of Idealized Polar Clouds: Large Eddy Simulations Driven by a GCM
Seasonal Cycle of Idealized Polar Clouds: Large Eddy Simulations Driven by a GCM
复制标题
理想化极地云的季节周期：GCM 驱动的大涡模拟
DOI：
10.1029/2021ms002671
复制
发表时间：
2022
影响因子：
6.8
通讯作者：
Eisenman, Ian
中科院分区：
文献类型：
--
作者：
Zhang, Xiyue;Schneider, Tapio;Shen, Zhaoyi;Pressel, Kyle G.;Eisenman, Ian
极地云反馈的不确定性要求对云对气候变暖的响应过程有更深入的了解。作为改善过程理解的第一步，我们采用了一种新的模式框架，使用大涡模拟(LES)来研究当前气候下极地云的季节周期，该框架明确地解决了云的动力学问题。由理想大气环流模式(GCM)分解的水平和垂直热量和水汽平流被规定为LES中的强迫。在规定的海冰厚度下，LES也被强迫，但地面温度、大气温度和湿度在没有轻推的情况下自由演变。没有水汽和云反馈的半射线辐射传输方案使GCM和LES比更复杂的方案更容易实现封闭的能量预算。这使得两个模型中的平均状态可以被一致地比较，而不会因为与更全面的辐射的相互作用而增加复杂性。结果表明，LES与GCM的季节周期密切相关，LES中低层云的季节周期与观测结果基本一致：夏季末秋初云液最大，冬季云以对流层上层冰为主。夏季大范围的水汽平流为含液云提供了主要的水汽来源，而冬季的温度平流峰使大气相对干燥，减少了云的凝结。我们开发和使用的框架可广泛用于研究云过程和极地云对气候变暖的响应。
The uncertainty in polar cloud feedbacks calls for process understanding of the cloud response to climate warming. As an initial step toward improved process understanding, we investigate the seasonal cycle of polar clouds in the current climate by adopting a novel modeling framework using large eddy simulations (LES), which explicitly resolve cloud dynamics. Resolved horizontal and vertical advection of heat and moisture from an idealized general circulation model (GCM) are prescribed as forcing in the LES. The LES are also forced with prescribed sea ice thickness, but surface temperature, atmospheric temperature, and moisture evolve freely without nudging. A semigray radiative transfer scheme without water vapor and cloud feedbacks allows the GCM and LES to achieve closed energy budgets more easily than would be possible with more complex schemes. This enables the mean states in the two models to be consistently compared, without the added complications from interaction with more comprehensive radiation. We show that the LES closely follow the GCM seasonal cycle, and the seasonal cycle of low‐level clouds in the LES resembles observations: maximum cloud liquid occurs in late summer and early autumn, and winter clouds are dominated by ice in the upper troposphere. Large‐scale advection of moisture provides the main source of water vapor for the liquid‐containing clouds in summer, while a temperature advection peak in winter makes the atmosphere relatively dry and reduces cloud condensate. The framework we develop and employ can be used broadly for studying cloud processes and the response of polar clouds to climate warming.
登录
查看更多内容
理想化混合相层积云对气候扰动的敏感性
影响因子：
8.9
作者：
Xiyue Zhang;T. Schneider;C. Kaul
通讯作者：
C. Kaul
副热带云顶边界层大涡模拟：2.云对气候变化的响应
影响因子：
6.8
作者：
Zhihong Tan;T. Schneider;J. Teixeira;K. Pressel
通讯作者：
K. Pressel
副热带云顶边界层大涡模拟：1. 封闭地表能量平衡的强迫框架
影响因子：
6.8
作者：
Zhihong Tan;T. Schneider;J. Teixeira;K. Pressel
通讯作者：
K. Pressel
影响因子：
6.8
作者：
Zhaoyi Shen;K. Pressel;Zhihong Tan;T. Schneider
通讯作者：
Zhaoyi Shen;K. Pressel;Zhihong Tan;T. Schneider
影响因子：
6.8
作者：
Pressel KG;Mishra S;Schneider T;Kaul CM;Tan Z
通讯作者：
Tan Z