1998/99년 겨울의 북태평양 regime shift 원인 분석

Abstract

We examine a possible mechanisms to lead the North Pacific regime shift of the winter of 1998/99. Since 1976/77 climate regime shift, the sea surface temperature(SST) in the North Pacific exhibits a long-term warming trend in the western and central North Pacific, which is mainly due to the two regime shifts which occurred in the winter of 1988/89 and 1998/99 regime shift, respectively. In particular, the 1998/99 regime shift is characterized by a dipole-like structure along 40°N where a significant warming in prominent in the southwestern and central North Pacific. It is found that slow dynamic adjustments of SST and zonal wind with the meridional heat exchange through the thermal advection is responsible for the 1998/99 regime shift. That is, an intrinsic multi-decadal SST oscillation in the North Pacific contributes to the 1998/99 regime shift. Furthermore, there exists another possibility, which is associated with the tropical-midlatitude interactions through oceanic teleconnections via Kuroshio current. Kuroshio currents, which is originated from the western tropical Pacific, carry more warm water and heat to the western North Pacific after the 1998/99. It is found that the western tropical Pacific SST shows a prominent warming since 1998/99, indicating that the oceanic teleconnections contribute to lead the 1998/99 North Pacific shift.d central North Pacific, which is mainly due to the two regime shifts which occurred in the winter of 1988/89 and 1998/99 regime shift, respectively. In particular, the 1998/99 regime shift is characterized by a dipole-like structure along 40°N where a significant warming in prominent in the southwestern and central North Pacific. It is found that slow dynamic adjustments of SST and zonal wind with the meridional heat exchange through the thermal advection is responsible for the 1998/99 regime shift. That is, an intrinsic multi-decadal SST oscillation in the North Pacific contributes to the 1998/99 regime shift. Furthermore, there exists another possibility, which is associated with the tropical-midlatitude interactions through oceanic teleconnections via Kuroshio current. Kuroshio currents, which is originated from the western tropical Pacific, carry more warm water and heat to the western North Pacific after the 1998/99. It is found that the western tropical Pacific SST shows a prominent warming since 1998/99, indicating that the oceanic teleconnections contribute to lead the 1998/99 North Pacific shift.