Monsoon low pressure system like variability in an idealized moist model
Monsoon low pressure system like variability in an idealized moist model
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季风低压系统类似于理想化潮湿模型中的变化
DOI：
10.1175/jcli-d-19-0289.1
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发表时间：
2019
影响因子：
4.9
通讯作者：
Adames, Ángel F.
中科院分区：
文献类型：
--
作者：
Clark, Spencer K.;Ming, Yi;Adames, Ángel F.
本文表明，南亚季风区向西传播的季风低压系统样扰动可以通过加入简化的陆地参数化而在理想的潮湿环流模式中模拟。陆地被参数化为具有周围平板海洋的十分之一的热容量，蒸发受到桶形水文模型的限制。利用回归分析阐明了模拟风暴的性质，并与前人文献和再分析的综合gcm风暴合成结果进行了比较。这些风暴在异常Ertel位涡度上与再分析的风暴具有相似的垂直剖面。然而，传播似乎并不受-漂移的强烈影响。相反，除了Ertel位涡预算中垂直平流项对扰动的增长和维持的重要性外，它似乎与线性水汽涡不稳定性理论更接近。本文的结果表明，简化的GCM配置可能能够更清楚地了解季风低压系统对平均状态气候变化的敏感性。
In this paper, it is shown that westward-propagating monsoon low pressure system–like disturbances in the South Asian monsoon region can be simulated in an idealized moist general circulation model through the addition of a simplified parameterization of land. Land is parameterized as having one-tenth the heat capacity of the surrounding slab ocean, with evaporation limited by a bucket hydrology model. In this model, the prominent topography of the Tibetan Plateau does not appear to be necessary for these storm systems to form or propagate; therefore, focus is placed on the simulation with land but no topography. The properties of the simulated storms are elucidated using regression analysis and compared to results from composites of storms from comprehensive GCMs in prior literature and reanalysis. The storms share a similar vertical profile in anomalous Ertel potential vorticity to those in reanalysis. Propagation, however, does not seem to be strongly dictated by beta drift. Rather, it seems to be more closely consistent with linear moisture vortex instability theory, with the exception of the importance of the vertical advection term in the Ertel potential vorticity budget toward the growth and maintenance of disturbances. The results presented here suggest that a simplified GCM configuration might be able to be used to gain a clearer understanding of the sensitivity of monsoon low pressure systems to changes in the mean state climate.