鄂霍次克海晚第四纪以来古环境演化
PALEOENVIRONMENTAL CHANGES IN THE OKHOTSK SEA SINCE LATE PLEISTOCENE AND ITS DRIVING FORCE
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摘要: 鄂霍次克海是北太平洋第二大边缘海,在"海-陆-气-冰"复杂的相互作用下,形成了独特的海洋环境,并以高生产力、季节性海冰覆盖以及作为北太平洋中层水换气源(ventilation)为特征。对晚第四纪鄂霍次克海海冰扩展,表层生产力、表层海水温度以及中层水演化等的研究显示,鄂霍次克海海冰覆盖面积变化与北太平洋亚极区上空大气环流活动中心位置和强度变化有关,黑龙江径流及Soya暖流仅在局部地区和局部时间有影响;海冰扩张和消退不仅影响鄂霍次克海的沉积作用,还影响着表层生产力的演化、中层水团的形成速率及规模,进而影响区域及全球碳循环及北太平洋水团的换气作用。提出了鄂霍次克海未来研究中应该关注的几个主要科学问题,认为了解鄂霍次克海海冰扩张和消退的历史是认识鄂霍次克海古环境演化的钥匙。Abstract: The Okhotsk Sea is the second largest marginal sea in the north Pacific Ocean. The marine environment of the Okhots Sea is very special under the complex interactions among ocean,land,atmosphere and ice,and characterized by high productivity, seasonal sea ice cover, and the ventilation source of the North Pacific Intermediate Water.Our results show that the advance and retreat of sea ice are mainly related to the strength and the active center of the atmosphere circulation over the subarctic Pacific Ocean. The influence of the sea ice cover by the Soya current and the Amur River only exist in a limited area and limited time. The advance and retreat of sea ice influence not only the sedimentation,but also the change in surface productivity and the formation of North Pacific Intermediate Water,and as the result the regional and global carbon cycle and the ventilation of the North Pacific Intermediate Water are also effected. In this study, we propose some key science questions for future study and conclude that the key to understand the paleoenvironmental changes in the Okhotsk Sea is to collect more information about the sea ice advance and retreat in the Okhotsk Sea.