Mechanisms of Arctic Surface Air Temperature Change in Response to the Madden–Julian Oscillation
Mechanisms of Arctic Surface Air Temperature Change in Response to the Madden–Julian Oscillation
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DOI：
10.1175/jcli-d-11-00566.1
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发表时间：
2012-03
影响因子：
4.9
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：在这项研究中，利用滞后复合材料和热力学能量方程的预测，研究了与马登-朱利安振荡（MJO）相关的北半球冬季北极表面气温（SAT）变化的机制。使用惠勒和亨登 MJO 指数，将 MJO 分为 8 个阶段，其中第 1 阶段（第 5 阶段）对应于海洋大陆和西太平洋的对流减少（增强）。结果表明，与 MJO 第 5 阶段（第 1 阶段）相关的更局部（均匀）热带对流加热导致向极地传播的罗斯贝波的激发增强（减少），从而导致北极变暖（变冷）。研究发现绝热变暖/冷却、涡流热通量以及随后的向下红外辐射 (IR) 通量变化对于北极 SAT 变化非常重要。绝热变暖/变冷引发了北极SAT变化，然而，随后的涡流热通量做出了更大的贡献。由此产生的 SAT 成绩...
AbstractUsing lagged composites and projections with the thermodynamic energy equation, in this study the mechanisms that drive the boreal winter Arctic surface air temperature (SAT) change associated with the Madden–Julian oscillation (MJO) are investigated. The Wheeler and Hendon MJO index, which divides the MJO into 8 phases, where phase 1 (phase 5) corresponds to reduced (enhanced) convection over the Maritime Continent and western Pacific Ocean, is used. It is shown that the more zonally localized (uniform) tropical convective heating associated with MJO phase 5 (phase 1) leads to enhanced (reduced) excitation of poleward-propagating Rossby waves, which contribute to Arctic warming (cooling). Adiabatic warming/cooling, eddy heat flux, and the subsequent change in downward infrared radiation (IR) flux are found to be important for the Arctic SAT change. The adiabatic warming/cooling initiates the Arctic SAT change, however, subsequent eddy heat flux makes a greater contribution. The resulting SAT chan...