| Variation of Sea Surface Height (SSH) and Sea Surface Temperature (SST) east of Taiwan is closely connected to the variation of Kuroshio, and is important in climate variation. In this paper, we use satellite observational data with high time and space resolution, according to high space resolution ocean model (OFES) output data and other oceanography data, use simple ocean model, through theoretical and statistical analysis, series of research are investigated on characteristics and mechanisms of SSH and SST east of Taiwan, innovative results obtained are as follows:1. In the region of 2 countercurrents (Subtropical Countercurrent and Hawaiian Lee Countercurrent) in the North Pacific, it is discovered that dominant low frequency variation of SSH is of period of 70-210 days, its amplitude is much larger than the amplitude of annual variation; because in the Subtropical Countercurrent (STCC) region, the flow direction of surface STCC and subsurface North Equatorial Current is opposite, the existence of mode water decreases subsurface vertical density gradient, ocean Rossby wave with period of 70-210 day is unstable and its amplitude increases when propagating eastward, amplitude reaches its maximum east of Taiwan; while in the region of HLCC, 70-210 day baroclinic Rossby wave is stable in the western part of countercurrent, amplitude doesn't increase when propagating westward; in the region east of Taiwan, annual Rossby wave is stable, so, 70-210 day variation amplitude is larger than annual variation amplitude east of Taiwan.2. It is discovered amplitude of interannual variation of wind driven SSH is larger than amplitude of annual variation, the dominant period is 2-7 years, this is because sea surface wind anomaly caused by ENSO mainly appears in the middle of subtropical North Pacific (21-32°N, 170°E-160°W), the Rossby wave driven by this anomaly signal propagates to the east of Taiwan, induces interannual variation of SSH and Kuroshio transport east of Taiwan; 50% of interannual SSH variation east of Taiwan can be explained by linear baroclinic Rossby wave theory.3. The western boundary current's role in SST seasonal variation is first brought forward using high resolution (9km) satellite observational SST data and other data: because mid-latitude mixed layer is thicker and SST meridional gradient increases in winter, the warm (cold ) advective effect of western boundary current becomes more important, forms the asymmetrical effect of western boundary current on SST—the effect is more important in winter than in summer; this effect results in SST annual range in Kuroshio east of Taiwan is smaller than SST annual range in the interior ocean east of Kuroshio.4. It is discovered in the region east of Taiwan, seasonal variation of SST and SSH is not of the same phase, 127°E-134°E is the maximum region of SST seasonal variation, the dominant period of SST seasonal variation in this region is 60-70 day and 110 day. The result shows, in intraseasonal time scale, this region is affected by northward propagation of atmosphere intraseasonal variation, anticyclonic (cyclonic) anomaly moves near this region from southeast induces upward velocity decreases (increases), cloud water decreases (increases), sea surface wind speed decreases (increases), SST decreases (increases); changes of wind curl and wind speed lead changes of SST, cloud water.The results above increase our understand on SSH and SST variation east of Taiwan, explain the phenomenon why～100 day variation exceed annual variation east of Taiwan and in Luzon Strait Kuroshio which was found using buoy observational data by some scientist, and bring forward new questions meanwhile.
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