A simple model of coupled synoptic waves in the land surface and atmosphere of the northern Sahel
A simple model of coupled synoptic waves in the land surface and atmosphere of the northern Sahel
复制标题
萨赫勒北部陆地表面和大气耦合天气波的简单模型
DOI：
10.1002/qj.343
复制
发表时间：
2008
影响因子：
8.9
通讯作者：
D. Parker
中科院分区：
文献类型：
--
作者：
D. Parker
开发了一个简单的动态模型来描述观察到的萨赫勒北部大气和土壤湿度模式之间的相互作用。在该模型中，大气遵循准地转动力学，而陆地-大气耦合则通过简单的线性关系来描述。相对于大气和陆地表面的平衡状态，干燥表面加热大气边界层，而潮湿表面冷却边界层。反过来，假设在大气扰动的凉爽、潮湿阶段达到最大的云过程，通过润湿（降雨）和减少入射太阳通量来冷却地表。这些假设导致了一个线性系统，可以对其进行数值求解以获得模态解及其伴随物（最佳激励）。没有详细探讨潮湿对流对大气状态的影响。
A simple dynamic model is developed to describe the observed interactions between the atmosphere and the soil moisture patterns of the northern Sahel. In the model, the atmosphere follows quasi‐geostrophic dynamics, while land‐atmosphere coupling is described by simple linear relationships. Dry surfaces heat the atmospheric boundary layer, while wet surfaces cool the boundary layer, relative to the equilibrium state of the atmosphere and land surface. In turn, cloud processes, which are assumed to maximise in the cool, humid phase of an atmospheric disturbance, cool the land surface through wetting (rainfall) and reduction of the incoming solar flux. These assumptions lead to a linear system which can be solved numerically to obtain modal solutions, and the adjoints (optimal excitation) of these. Moist convective influences on the atmospheric state are not explored in detail.