| The long-term structural changes of temperature, salinity, and current at East China Sea are closely related to the coastal climate, ecological environment, and sea operations of China. Knowing these changes is the scientific basis to safeguard our offshore development activities, environmental quality, and biological sources. And changes of the marine elements in oceans and of the spread of the abnormal signal would also have a certain impact on our coastal waters.In this paper, data along the 137°E and PN,TK section gathered during 1967-2003 were used to study the interannual variability in the northern ECS, through statistical methods such as, linear fit analysis,correlation analysis, dynamic height calculation and wavelet spectrum analysis.The conclusions were drawn as follows:1 Northern mean position of 28°C isotherm along the 137°E section is 8.9°N in winter,it varies with a period of 14 years( This is consistent with the period[29] of the zonal movement of surface warm water in the western Pacific warm pool),and it moved northward with a speed of 10km/a.2 Temperature on the south of the 137°E section is ralated with the vertical displacement of thermocline accompanied by El Nino and La Nina events. In this area at depth of 300m to 400m (NECC range) has negative correlations with this variation so that it strengthens the current of the NECC during El Nino events and weakens it during La Nina events. Temperature and salinity of PN and TK section respond with the variation of NECC range 2 years later.Their correlative coefficient is 0.56 and 0.57.3 When the meander of Kuroshio occurs ,there will be large-scale low-temperature and low salinity anomalies at 100 meters deeper area on the norhern of the 137°E section. However, there is positive anomaly of salinity at 700 meter deeper area, i.e. the salinity changes of this area is anti-phase to that of upper area. It is mainly due to the influence of the large cold water in the west side of Japan Izu islands generated by the meander of Kuroshio. The distribution of salinity in this section relatively low at the middle, and relatively high at the upper and the bottom layers. Therefore, when the 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, which causes the anti-phase changes above. Moreover, there is an upward trend of upper ocean salinity, whereas a downward trend of lower ocean salinity, nevertheless, the overall salinity remains almost unchanged.4 Distributing of intermediate water and sub-surface saline water has big differences from year to year .Intensity of intermediate water trends bigger,and the sub-surface saline water trends calmly.5 Meander of Kuroshio result in the descension of temperature at the 137°E section.This descension correlates with PN,TK section hardly.But temperature and salinity of these three sections varies in-phase upper 250m layer.So variation of temperature and salinity at these three sections associates by current——Kuroshio. 6 When meander of Kuroshio occurs,the flux of PN section will increase. the nothern of 137°E section varies with negative correlations. if meander of Kuroshio doesn't occurs ,flux of PN section varies consistently with the 137°E's.The increasing of flux over PN section is associate with positive temperature anomaly, however negative temperature anomaly is associated with El Nino[62].Temperature is decided by their intensity,the weaker one prevent the effects of the other.
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