New Insights on Subseasonal Arctic–Midlatitude Causal Connections from a Regularized Regression Model
New Insights on Subseasonal Arctic–Midlatitude Causal Connections from a Regularized Regression Model
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DOI：
10.1175/jcli-d-19-0142.1
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发表时间：
2019-12
影响因子：
4.9
通讯作者：
M. McGraw;E. Barnes
中科院分区：
文献类型：
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作者：
M. McGraw;E. Barnes
北极-中纬度遥相关是复杂和多方面的。通过设计，有针对性的建模研究通常只关注一个方向的影响，通常是中纬度大气对北极变化的反应。双向的，耦合的反馈北极和中纬度环流之间的次月时间尺度的探讨使用正则化的回归模型制定周围的格兰杰因果关系。正则化回归模型表明，有北极温度驱动中纬度环流响应的区域，以及中纬度环流驱动北极响应的区域;然而，这些区域很少重叠。在许多区域，在次月时间尺度上，中纬度环流驱动北极温度变率，突出了中纬度环流在影响北极方面的重要作用。特别是，正则化回归模型结果支持了最近的工作，表明观察到的欧亚大陆高压异常在次月时间尺度上驱动了北极的显着响应，而不是由北极驱动。
Arctic–midlatitude teleconnections are complex and multifaceted. By design, targeted modeling studies typically focus only on one direction of influence—usually, the midlatitude atmospheric response to a changing Arctic. The two-way, coupled feedbacks between the Arctic and the midlatitude circulation on submonthly time scales are explored using a regularized regression model formulated around Granger causality. The regularized regression model indicates that there are regions in which Arctic temperature drives a midlatitude circulation response, and regions in which the midlatitude circulation drives a response in the Arctic; however, these regions rarely overlap. In many regions, on submonthly time scales, the midlatitude circulation drives Arctic temperature variability, highlighting the important role the midlatitude circulation can play in impacting the Arctic. In particular, the regularized regression model results support recent work that indicates that the observed high pressure anomalies over Eurasia drive a significant response in the Arctic on submonthly time scales, rather than being driven by the Arctic.