1945-2010 Years Kuroshio Zone Temperature PN Section Season / Interannual / Decadal Changes

The ocean plays a vital role in the climate system, seawater temperature is areflection of the basic parameters of the heat balance of marine water body, it’s animportant indicator of climate too. It’s the focus of the21st century oceanographyclimate studies that marine multi-scale change process, mechanism and predictability.The Kuroshio Current of the East China Sea is the main driving force of Chinas coastalcirculation variability and plays an important role in China’s climate and environment.It has important implications that explore the Kuroshio temperature seasonal,interannual and decadal variation process research. It provides a basis for furtherunderstanding and forecasting the influence of the Kuroshio on seasonal, interannualclimate in China.Using the Ishii (1945-2010) marine datasets building the temperature databaseof the PN section in Kuroshio of East China Sea, by extract section eigenvalues,numerical statistical analysis method explore PN section Four Seasons temperatureinterannual and decadal variation, try to analyze the main factors affecting the PNsection temperature change.The conclusions show that:1. From1945to2010, the less than300m seawater temperature significantlywarming,300~500m is buffer layer, more than500m cooling main, at PN section inspring, summer, autumn and winter; the upper seawater temperature mutated in the1990s, lower seawater temperature mutated around1964, the entire PN sectiontemperature difference has expanded dramatically. The greatest contribution layerfor warming is less than100m, the greatest contribution layer for cooling is morethan500m.2. From1978to2010, less than100m has a warming core, the appearing stageis from1978to1988,1989to1999for the development phase, from2000to2010asthe strong stage, the warming core expand deepen over time. Warming strongsummer and fall of the upper reach0.95℃and1.1℃, cooling most strongly to the bottom of the spring and summer,-0.67℃and-0.65℃, respectively.3. The PN Section temperature with2to5years of the primary cycle andsub-cycle of11years, compare with the same period index of El Nino-SouthernOscillation (ENSO) and Pacific Decadal Oscillation (PDO), with a good correlation toinfer from the primary cycle regulation by ENSO, whether the sub-cycle by thesunspot cycle change remains to be further argued.4. Ahead about13months the El Nino3.4index with the PN section less than50meters temperature index reach the highest correlation coefficient, but only insummer (significant at98%confidence level), that the surface temperature duringsummer in PN section with ENSO has a lead-lag correlation. And proved that ENSOmay impact the PN section temperature through circulation after13months,affecting mainly less than50m.5. Less than200m PN section Seawater temperature in spring and summer lagsPDO6~16months, and during winter, more than200meters lags PDO3~7months,with the increase in the depth of the correlation coefficient is reduced. PDO affectthe temperature of PN section and the affected depth changes with the seasons, it’sless than200m in the spring, its less than50m in summer, it’s not obvious in fall, it’srange100to700m in winter.