Prediction of Short-Term Variations of the Warm-Core Rings in the Sea Off Sanriku

三陆海岸外的海域被认为是复杂的海洋环境，它由黑潮和沽潮洋流以及许多暖核环形成。由于这个特点，它有时被称为汇流带。由于形成了良好的商业渔场，该海域对日本渔业很重要。本研究的目的是建立一个预测暖核环短期变化的原型系统。首先，我们对日本东北大学本地接收的NOAA-A VHRR数据进行再处理，生成每天4-6张海温图像。通过对这些图像的调查，我们挑选了92个短期变化事件。针对所有这些事件，我们使用轮廓动力学模型进行了仿真实验，该模型对每个事件都显示了良好的性能。暖核环由东大洋向研究区传播，其数量密度增大。引起研究区短期变化的因素之一是暖核环与高数目密度的相互作用。我们分析了高度计海表高度和高分辨率海表温度图像，提出了估算暖核环周围海表高度和海表速度的方法。在整个研究过程中，以卫星高度计和海温测量值为初始条件，建立了一个预测海温锋位置的基本系统，该系统显示了暖核环的位置。

The sea off Sanriku Coast is known as complicated oceanic conditions, which is formed by the Kuroshio and Oyashio currents and many warm-core rings. Because of this feature, it is sometime called as confluence zone. Since good commercial fish grounds are formed, this sea area is important for the Japanese fisheries. The purpose of present study was to develop a prototype system for forecasting of the short-term variations relating to the warm-core rings.First, we reprocessed the NOAA-A VHRR data locally received at the Tohoku University for generation of 4-6 sea surface temperature images in a day. Through investigation of these images, we picked up 92 events of the short-term variations. Foe all of these events, we conducted simulation experiments using the contour dynamics model, which shows good performance for each event. The warm-core rings propagate from the eastern ocean into the study area, and its number density becomes high. One of the factors which activate the short-term variations in the study area is the interaction of the warm-core rings with the high-number density.We analyzed the altimeter sea-surface height together with the high-resolution Sea Surface Temperature images, and developed methodology to estimate the sea surface height and surface velocity around the warm-core rings. Throughout this study, a basic system is established to predict the positions of SST fronts, which shows the locations of warm-core rings, using the satellite altimeter and SST measurements as the initial conditions.