运用海冰生物标志物(IP25)重建第四纪末期冰岛北部陆架区的海冰变化

项目名称： 运用海冰生物标志物(IP25)重建第四纪末期冰岛北部陆架区的海冰变化

项目编号： No.41506214

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 海洋科学

项目作者： 肖晓彤

作者单位： 中国海洋大学

项目金额： 21万元

中文摘要： 海冰作为极地区域的一个重要组成部分，对全球的温盐环流和气候变化有重要作用。近几年北极夏季海冰覆盖面积的急剧减小引起了社会各界的关注，但是目前对北极海冰长时间尺度高分辨率的变化规律还缺乏研究。在此申请中，我们选用位于冰岛北部陆架区的沉积物岩芯，重建长期的（过去18000年）连续的海冰变化记录。此区域位于北极圈边缘以及现代冬季海冰覆盖边缘以南，对海冰、洋流及气候变化比较敏感。我们拟运用一种新的海冰生物标志物IP25（含25个碳原子的海冰指标），并结合海源浮游植物生物标志物（菜子甾醇、甲藻甾醇和短链正构烷烃），得到定量指标PIP25（Phytoplankton marker-IP25 index）的记录，定量且高分辨地重建此区域的海冰变化规律，揭示海冰变化对洋流和气候变化的响应。海冰对第四纪末期暖期和冷期事件的响应对认识和了解现代海冰的快速变化有重要参考意义，可为预测未来海冰变化提供可靠的数据。

中文关键词： 海冰；生物标志物；IP25；沉积物；冰岛

英文摘要： Sea ice is a fundamental component of Polar Regions, contributing to global thermohaline circulation and climate changes. The rapid shrinking Arctic summer sea-ice cover is of major interest for the entire community. So far, the long-term and high-resolution study on Arctic sea-ice variability is still sparse. In this study, we will use the marine sediment core taken from the North Icelandic shelf to reconstruct the long-term and continuous sea-ice variability during the past 18000 years. The North Icelandic shelf is located at the boundary of the Arctic Circle and South of present-day winter ice edge, which is sensitive to the changes of sea ice, currents and Earth’s climate. We will use the novel sea-ice biomarker IP25 (Ice Proxy with 25 carbon atoms), combined with open-water phytoplankton derived biomarkers (e.g. brassicasterol, dinosterol and short-chain n-alkanes), to obtain the quantitative index PIP25 (Phytoplankton marker-IP25 index) records，estimating the sea-ice variability more quantitatively and indicating its response to the global climate change. To understand how the sea-ice variability responds to the warm and cold events during the late Quaternary is of significant importance for interpreting the rapid decline of modern sea-ice cover, providing promising reliable data for future prediction.

英文关键词： sea ice;biomarker;IP25;sediment;Iceland