サンゴ骨格の酸素同位体比とその変動幅 : 海洋表層の水温と塩分の水平分布復元に向けて(<特集>サンゴ年輪と低緯度の海洋環境)

概要

論文の詳細を見る
Although tropical oceans are a key component of the global climate system, their behavior in the past - even only a few decades ago - remains poorly characterized. Coral skeletons can provide several centuries of continuous paleoclimatic records with weekly to annual resolution. The skeletal oxygen isotope ratio (δ^<18>O) is one of the most commonly used coral-based paleoclimatic proxies. The skeletal δ^<18>O values reflect a combination of temperature and the δ^<18>O of ambient surface seawater, and seawater δ^<18>O and sea surface salinity are affected by similar factors. Many calibration studies have sought to validate skeletal δ^<18>O as a paleoclimatic tracer and to define the relationship between skeletal δ^<18>O, temperature, seawater δ^<18>O and salinity. The time resolution of this calibration is increasing; it currently occurs biweekly in the Palau Islands in the tropical Western Pacific. Generally, changes in sea surface temperature and seawater δ^<18>O have almost the same effect on changes in skeletal δ^<18>O, both temporally and spatially. Local contribution rates of these two factors to skeletal δ<18>O differ owing to regional climatic conditions. Parallel studies of detailed calibrations and an expansion of coral skeletal δ^<18>O datasets over the next decade are anticipated to lead to many developments in paleoclimatic understanding.
日本地球化学会の論文
2004-12-27