We evaluate the Oyashio and Kuroshio fronts latitudinal transition under the projected climate change scenarios using eddy resolving regional ocean climate projection products from 1981 to 2100. The regional ocean climate projections are produced based on dynamical downscaling of four CMIP5 models and two RCP experiments RCP2.6 and RCP8.5. Two approaches of the fronts detection methods are compared. One is conventional approach based on subsurface specific isotherm and another is newly proposed approach based on the Oyashio and Kuroshio water temperature and salinity (TS) profiles that may change as the global warming progresses. It is found that the Oyashio TS profile rapidly shift to be high both in temperature and salinity in RCP8.5 cases while the Kuroshio TS profile shows small change toward the end of the twenty-first century in all cases. Northward shift of the Oyashio and Kuroshio fronts reaches 2° northward by the late twenty-first century in extreme case of RCP8.5 cases from the temperature-based definition. On the other hand, the northward shifts of fronts are less than 1° when we use the TS-based definition. The comparison of both fronts positions with the surface velocity distributions suggest that the TS-based definition captures transitions of the fronts better than the temperature-based definition.

中文翻译：

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在预计的21世纪气候变化下检测Oyashio和Kuroshio阵线

我们使用涡旋解析1981年至2100年的区域海洋气候预测产品，在预估的气候变化情景下评估了Oyashio和Kuroshio前沿的纬度转变。区域海洋气候预测是基于四个CMIP5模型的动态缩减和两个RCP实验RCP2.6得出的和RCP8.5。比较了前沿检测方法的两种方法。一种是基于地下特定等温线的常规方法，另一种是基于Oyashio和Kuroshio水温和盐度（TS）剖面的新提出的方法，这些剖面可能会随着全球变暖的进行而改变。发现在RCP8.5情况下，Oyashio TS曲线迅速转变为高温和高盐度，而在所有情况下，黑潮TS曲线在20世纪末都显示出很小的变化。根据温度的定义，在RCP8.5的极端情况下，到21世纪后期，Oyashio和Kuroshio前沿的北移达到了2°。另一方面，当使用基于TS的定义时，锋面的北移小于1°。两种锋面位置与表面速度分布的比较表明，基于TS的定义比基于温度的定义更好地捕获了锋面的过渡。