摘要
利用日本气象厅对137°E断面32个站位每年2次的连续观测资料,分析了此断面3°N～34°N在1967～2003年期间的温度、盐度特征及其年际变化。资料分析表明,该断面温度变化有2个极大值区,低纬度极大值区温度变化与厄尔尼诺事件有重要关联。在厄尔尼诺事件达到峰值前,此区域温跃层向上抬升,冬季此区域下层300～400 m处(北赤道逆流区)的温度出现与以上抬升反相位的变化,即在厄尔尼诺发生时可以加大等温线的倾斜,从而加强了北赤道逆流,在拉尼娜发生时正好相反。30°N以北的温度变化极大值区的温度变化主要受日本以南黑潮大弯曲的影响,当黑潮出现弯曲时,该区出现的气旋式涡旋造成深层水的上涌,导致该区200 m以深出现大范围降温。以700 m为界,日本以南黑潮区上、下层盐度的年际变化相反,这是由于该海域盐度的气候分布特征为中层低、上层和底层相对高所造成的。所以当水柱上涌时,原本的高盐水被低盐水代替,而原本的低盐水被高盐水代替,导致了以上反相位的变化。冬季28℃等温线的北端位置不仅有14 a的变化周期,而且整个暖池37 a来以平均每年0.1个纬距的速度向北移动。中层低盐水(34.2 psu等盐线分布)的强度分布有明显的年际差异,并且逐年加强。
Based on the hydrographic data gathered along the 137°E meridian by the R/V Ryofu Maru of Japan Meteorological Agency(JMA),the characteristics of temperature and salinity and their interannual vari- abilities are analyzed along this section from 3°N to 34°N.The temperature variation has two maximum value ranges,the one in the south is related with the vertical displacement of the thermocline accompanied by El Nino and La Nina events.In this area at depth 300 m to 400 m(NECC range)the temperature has negative correla- tions with this variation so that it strengthens the current of the NECC during El Nino events and weakens it during La Nina events.The one in the north is affected by the Kuroshio meander.When the Kuroshio meander occurs,there is a counterclockwise current on the surface of this region,causing deep water upwelling,which leads to large-scale cooling of the water below 200 meters in this region.The salinities in the upper layer(depths 200 to 600 m)and lower layer(depths 800 to 1 000 m)are negatively correlated.The salinity in this area is rel- atively low in the middle,and relatively high in the upper and bottom layers.Therefore,when water column upwelling happens,the original high salinity water is replaced by low salinity water,while the original low salinity water is replaced by high salinity water,causing the anti-phase changes mentioned above.The distribu- tion of intermediate water varies from year to year,and its intensity tends to become higher.The 28℃isotherm varies with a period of 14 years in winter,and it moves northward with a speed of 10 km/a.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第S1期38-46,共9页
Periodical of Ocean University of China
基金
国家重点基础研究发展计划项目(2005CB422308)资助
