A Study on the Prediction of Anomalous Southward Intrusion of the Oyashio

本文研究了北太平洋异常南下入侵和北太平洋次北极环流的机制，特别是它们的可能预测方法。第一年，研究了南向异常侵入体产生的基本动力学。已有研究表明，由于阿留申低压向南发展引起的风应力变化，造成了奥亚西奥环流和亚北极环流的南下侵入(Sekine，1990)。由于冬季阿留申低压的南下发展，以及黑潮延伸区暖水的缺乏和津格鲁暖流的东移，可以预测奥雅希奥和亚北极环流的南下入侵。由此推断，南下入侵形成的更广的冷海表温度(SST)对全球大气环流有显著的影响。…之间的关系第二年研究了更多的异常南侵和全球大气环流的变化。由于阿留申低压的南下发展是太平洋/北美(PNA)型的一个过程，Oyashio和亚北极环流的异常南下入侵被证明是一种全球现象，它与赤道地区的ENSO现象有遥相关(Sekine和Suzuki，1991)。由于PNA模式往往出现在厄瓜多尔附近暖水出现的一年后，根据ENSO现象的演变，可以预测异常的南向入侵。由于阿留申低压的南下发展是由南侵冷海温独立形成的，南下入侵对阿留申低压南下发展的正反馈作用。然而，Sekine和Nakagawa(1992)和Sekine et al.(1992)研究表明，鄂霍次克海冬季海冰面积较小，存在异常的南向侵入，抑制了冬季大气的降温。由于全球大气和海洋的耦合变化是重要事件，因此未来的一些问题将被省略，以得出关于它们的整个系统的确切结论。较少

Mechanisms of the anomalous southward intrusion of the Oyashio and the subarctic circulations in the North Pacific have been studied with special reference to the possible prediction method for their occurrence. In the first year, the basic dynamics of the generation of the anomalous southward intrusion was studied. It has been demonstrated that the southward intrusions of the Oyashio and the subarctic circulation are due to the wind stress change by the southward development of the Aleutian Low (Sekine, 1990). The prediction of the southward intrusion of the Oyashio and subarctic circulation is show to be possible by the southward development of the Aleutian Low in winter and by the lack of the warm water detached from the Kuroshio Extension and eastward development of the Tsugaru Warm Current.It is inferred that the wider cold sea surface temperature (SST) formed by the southward intrusion has a remarkable influences on the global atmospheric circulation. The relationship between the … More anomalous southward intrusion and the global change in atmospheric circulation was studied in the second year. As the southward development of the Aleutian Low is one process of the Pacific/North American (PNA) pattern, the anomalous southward intrusion of the Oyashio and subarctic circulation is shown to be a global phenomena that has a teleconnection with the ENSO phenomenon in equatorial area (Sekine and Suzuki, 1991). Since the PNA pattern has a tendency to occur in one year later than the onset of the warm water appearance off Ecuador, the prediction of the anomalous southward intrusion is possible by the evolution of the ENSO phenomenon. Because the southward development of the Aleutian Lowis independently by formed by the cold SST due to the southward intrusion, the positive feedback of the southward intrusion to the the southward development of the Aleutian Low. However, Sekine and Nakagawa (1992) and Sekine et al. (1992) showed that the sea ice area in the Okhotsk Sea is relatively small in winter with the anomalous southward intrusion, which suppresses winter cooling of the atmosphere. As the coupled global changes in atmosphere and ocean are important events, some future problems are left out to draw a firm conclusion on their total systems. Less