Spatial-temporal variability of thermohaline intrusions in the northwestern tropical Pacific Ocean  

作　　者：LI YuanLong WANG Fan TANG XiaoHui 

机构地区：[1]Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2013年第9期1038-1043,共6页

基　　金：supported by the National Basic Research Program of China (2012CB417401);the National Natural Science Foundation of China (40890152)

摘　　要：Using repeated hydrographic measurements at 137°E,spatial-temporal variability of thermohaline intrusions in the northwestern tropical Pacific are investigated.Intrusions can be found in the main thermocline throughout the section,with their strength decreasing rapidly poleward.The strongest intrusions exist at the North Equatorial Countercurrent(NECC) where North/South Pacific thermocline water converges.These intrusions also exhibit temporal variations in strength which are closely associated with the meridional displacement of the NECC.Intrusion strength peaks in boreal winter when the NECC reaches its northernmost position of the year.At interannual time scale,intrusions tend to be weak(strong) during El Ni o(La Ni a) episodes.Variations in intrusion strength also lead to prominent fluctuation of lateral diffusivity K L and cross-front temperature flux F Θ.F Θ exhibits significant year-to-year changes which are well correlated with ENSO index,suggesting a possible role of intrusions in the low-latitude Pacific climate variability.Using repeated hydrographic measurements at 137°E, spatial-temporal variability of thermohaline intrusions in the northwestern tropical Pacific are investigated. Intrusions can be found in the main thermocline throughout the section, with their strength decreasing rapidly poleward. The strongest intrusions exist at the North Equatorial Countercurrent （NECC） where North/South Pacific thermocline water converges. These intrusions also exhibit temporal variations in strength which are closely associated with the meridional displacement of the NECC. Intrusion strength peaks in boreal winter when the NECC reaches its northernmost position of the year. At interannual time scale, intrusions tend to be weak （strong） during E1 Nifio （La Nifia） episodes. Variations in intrusion strength also lead to prominent fluctuation of lateral diffusivity KL and cross-front temperature flux Fo. Fo exhibits significant year-to-year changes which are well correlated with ENSO index, suggesting a possible role of intrusions in the low-latitude Pacific climate variability.

关 键 词：西北太平洋 热带海洋 入侵 时空变异 温盐 水文测量 时空变化 重复使用 

分 类 号：P731.1[天文地球—海洋科学]