摘要: |
利用1993~2017年海表面高度异常数据集,分析研究了西北太平洋季节内变化(20~120 d)的整体分布特征,结果表明空间上季节内信号在20°N附近海域(16°~24°N)最强,时间上在6~8月达到一年中的最大值。在吕宋海峡东侧(123.875°E,20.125°N)季节内信号周期(70 d)和传播速度(10.7~12.7cm/s)均大于吕宋海峡西侧(119.625°E,20.125°N)(60 d,6.5~7.8cm/s)。在大洋内部(123°~140°E,18°~24°N)存在准90 d的周期信号,传播速度约10.3cm/s。传播路径受黑潮的影响发生改变,由沿纬度西传转向向西北方向传播。第一斜压Rossby波理论对海表面高度季节内变化的周期和传播速度具有很好的解释性。 |
关键词: 西北太平洋 吕宋海峡 海表面高度 季节内变化 |
DOI:10.11759/hykx20190319003 |
分类号:P731.2 |
基金项目:国家自然科学基金项目(41576014) |
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Intraseasonal variability of sea surface height near the Luzon Strait |
YUAN Xin1,2,3, WANG Qing-ye1,2
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1.Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2.Key Laboratory of Ocean Circulation and Wave, Chinese Academy of Sciences, Qingdao 266071, China;3.University of Chinese Academy of Sciences, Beijing 100049, China
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Abstract: |
Based on the sea surface height anomaly dataset from 1993 to 2017, the intraseasonal variability (ISV, period of 20~120 days) in the Northwestern Pacific was investigated. Results showed strong ISV occurred in the latitude band centered on 20°N (16°~24°N), and was stronger during June~August. In the eastern part of the Luzon Strait (point B, 123.875°E, 20.125°N), the signal period (70 days) and propagation velocity (10.7~12.7 cm/s) were larger than the corresponding values (60 days, 6.5~7.8 cm/s) on the western side of the Luzon Strait (point A, 119.625°E, 20.125°N). In the open ocean (123°~140°E, 18°~24°N), ISV had a typical period of 90 days and a typical propagation speed of about 10.3 cm/s. The propagation pathway of the ISV is associated with the Kuroshio Current. The ISV signal in the open ocean propagates westward, then turns northwestward when it is approaching the coast. Theory values of the first baroclinic Rossby wave phase period and velocity were consistent with those of the ISV calculated from sea surface height. |
Key words: Northwestern Pacific Luzon Strait sea surface height intraseasonal variability |