日本近海の海水温変動と北半球気候変動との共時性

概要

論文の詳細を見る
Annual sea-surface temperatures (SSTs) (°C) were derived from a regression analysis between the ratio of warm- and cold-water diatoms (Td ratio) in 123 surface sediment samples around the Japanese Islands and measured mean annual SSTs (°C) at the core sites. The cross spectra between the atmospheric residual 14C (‰), and annual SSTs (°C) of cores DGC-6 (Japan Sea) and MD01-2421 (off Kashima), respectively, consist of five dominant periods: 6000, 2400, 1600, 950, and 700 years. The amplitude of fluctuations of annual SSTs (°C) in the millennial time scale during the Holocene after the Younger Dryas is within 6-10°C. Periodic variations of annual SSTs (°C) can be correlated within error to abrupt climatic events reported from different paleoclimatic proxy records in many regions of the Northern Hemisphere. The cooling time of annual SSTs (°C) also corresponds to the triple events of high 14C values in the atmospheric residual 14C records, as well as the Bond events in the North Atlantic.