The Pacific Meridional Mode and the Occurrence of Tropical Cyclones in the Western North Pacific
The Pacific Meridional Mode and the Occurrence of Tropical Cyclones in the Western North Pacific
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DOI：
10.1175/jcli-d-15-0282.1
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发表时间：
2016-01-01
影响因子：
4.9
通讯作者：
Jia, L.
中科院分区：
文献类型：
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作者：
Zhang, W.;Vecchi, G. A.;Jia, L.
本研究调查了太平洋经向模态 (PMM) 与西北太平洋 (WNP) 热带气旋 (TC) 活动之间的关联。研究发现，正PMM相有利于WNP中TC的出现，而负PMM相则抑制TC在WNP中的出现。观察到的关系与高分辨率 TC 解析地球流体动力学实验室 (GFDL) 面向预报的低海洋分辨率 (FLOR) 耦合气候模型的长期工业化前控制实验（1000 年）的关系一致。 FLOR 的敏感性实验进一步支持了观测值和模型中 PMM 和 TC 之间的诊断关系。 PMM对TC生成的调节主要是通过西北部地区特别是西北部地区的异常纬向垂直风切变(ZVWS)变化。异常ZVWS可归因于PMM正相期间大气对PMM模式西北部异常变暖的响应，这类似于经典的Matsuno-Gill模式。西太平洋国家公园上空的气旋流加强了对热带气旋形成的影响。本文确定的 TC 与 PMM 之间的显着关系可为 TC 的季节预报和解释西北部地区 TC 活动的变化提供有用的参考。
This study investigates the association between the Pacific meridional mode (PMM) and tropical cyclone (TC) activity in the western North Pacific (WNP). It is found that the positive PMM phase favors the occurrence of TCs in the WNP while the negative PMM phase inhibits the occurrence of TCs there. Observed relationships are consistent with those from a long-term preindustrial control experiment (1000 yr) of a high-resolution TC-resolving Geophysical Fluid Dynamics Laboratory (GFDL) Forecast-Oriented Low Ocean Resolution (FLOR) coupled climate model. The diagnostic relationship between the PMM and TCs in observations and the model is further supported by sensitivity experiments with FLOR. The modulation of TC genesis by the PMM is primarily through the anomalous zonal vertical wind shear (ZVWS) changes in the WNP, especially in the southeastern WNP. The anomalous ZVWS can be attributed to the responses of the atmosphere to the anomalous warming in the northwestern part of the PMM pattern during the positive PMM phase, which resembles a classic Matsuno-Gill pattern. Such influences on TC genesis are strengthened by a cyclonic flow over the WNP. The significant relationship between TCs and the PMM identified here may provide a useful reference for seasonal forecasting of TCs and interpreting changes in TC activity in the WNP.