Arctic Response to an MJO-Like Tropical Heating in an Idealized GCM
Arctic Response to an MJO-Like Tropical Heating in an Idealized GCM
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DOI：
10.1175/jas-d-11-0261.1
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发表时间：
2012-08
影响因子：
3.1
通讯作者：
C. Yoo;Sukyoung Lee;S. Feldstein
中科院分区：
文献类型：
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作者：
C. Yoo;Sukyoung Lee;S. Feldstein
摘要：使用初始值方法和理想化大气环流模型，研究了马登-朱利安振荡（MJO）影响北极表面气温（SAT）的机制。进行了与 MJO 第 1 阶段和第 5 阶段相对应的模型计算，因为之前的研究表明，这两个阶段分别与北极表面的冷却和变暖有关。指定了观测到的类似 MJO 的热带加热剖面，第 5 阶段（第 1 阶段）加热呈现出更加区域化的局部（均匀）空间结构。执行大型集合模型运行，其中每个集合成员的初始流由冬季气候以及从观测数据中随机选择的初始扰动组成。模型计算表明，MJO 第 5 阶段（第 1 阶段）之后，向极地波活动传播出热带的加强（减弱），这导致北极 SAT 的增加（减少）。检验T...
AbstractUsing an initial-value approach with an idealized general circulation model, the mechanisms by which the Madden–Julian oscillation (MJO) influences the Arctic surface air temperature (SAT) are investigated. Model calculations corresponding to MJO phases 1 and 5 are performed, as previous studies have shown that these two phases are associated with a cooling and warming of the Arctic surface, respectively. Observed MJO-like tropical heating profiles are specified, with the phase 5 (phase 1) heating taking on a more zonally localized (uniform) spatial structure. A large ensemble of model runs is performed, where the initial flow of each ensemble member consists of the winter climatology together with an initial perturbation that is selected randomly from observational data. The model calculations show that MJO phase 5 (phase 1) is followed by a strengthening (weakening) in the poleward wave activity propagation out of the tropics, which leads to an increase (decrease) in Arctic SAT. Examination of t...