石垣島安良崎のサンゴ骨格の酸素同位体比にみる冬期の水温変動と1988/1989年気候レジームシフト

概要

論文の詳細を見る
Precise and long term climate data are necessary to predict the magnitude of climate change in the future. The tropical regions are important subsystem of the global climate system because it receives over 50% of total amount of solar energy to the earth. Climate data, however, are available only for recent about 30 years. Thus climate reconstruction with proxies is urgently required. We conducted oxygen isotope analysis of the latest 30 years part of a 272 cm-long core of annually banded coral Porites sp. from Ishigaki Island, the Ryukyus, Japan to reconstruct sea surface temperature (SST) of the region. Significant correlation between coral skeletal oxygen isotope ratio and winter SST allow precise estimate of winter-time SST of the region. In the first half of the period, the winter SST of Ishigaki Island was strongly correlated to the development of winter Asian monsoon. After the climate regime shift in 1988/1989 at middle latitude Pacific, it showed no correlation to the monsoon and instead the influence of Kuroshio Current was suggested. Winter-time climate mechanism of the Ryukyu Islands region has changed since the regime shift. Further reconstruction of SST based on coral records at Ishigaki Island will greatly contribute to understand the climate system of the northern hemisphere.
日本地球化学会の論文
2006-12-26