过去千年尺度北极夏季海冰面积数据集的研发  

Reconstructed Arctic Summer Sea Ice Areal Extent over the Past Millennium

作　　者：任帅 郭辉[2] Ren,S.;Guo,H.(Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;State Key Laboratory of Hydroscience and Engineering,Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]中国科学院青藏高原研究所,北京100101 [2]清华大学水利水电工程系,水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《全球变化数据学报（中英文）》2022年第3期366-373,V0366-V0373,共16页Journal of Global Change Data & Discovery

基　　金：中华人民共和国科学技术部(2017YFA0603303)。

摘　　要：北极海冰是地球系统的重要组成部分。海冰的变化对极地地区,乃至中纬度地区(北美、欧亚大陆等)气候至关重要。近30年遥感观测发现北极海冰正在快速消融,而这一变化趋势是否超过了海冰变化的历史波动仍不清楚。厘清这一问题需要重建北极海冰的长时间变化序列。已有的诸多研究通常使用代用指标进行海冰范围或海冰密度的重建,然而这些研究多反映局部海域的海冰变化,缺乏北极海冰整体变化的信息。基于此,本研究尝试探索新的海冰重建方法,基于北极海冰高反照率的特点,构建海冰反照率-大气环流统计模型,据此重建过去千年尺度北极地区夏季海冰面积的时空变化。结果显示,该方法所模拟的北极地区夏季海冰面积的时空动态变化特征与遥感观测高度吻合。重建的过去千年海冰变化序列显示,近30年海冰快速消融趋势远超过了历史时期海冰面积的波动。本研究提出的海冰重建方法,为进一步重建历史时期更长尺度海冰变化奠定了基础。数据集表明,最大面积出现在1259年,面积约为870万km2;面积最小年份出现在2003年,面积约为538万km2,在700余年间,北极海冰最小面积与最大面积相差约为332万km2,面积减少了38%。Arctic sea ice is an important component of the Earth system.Changes in sea ice are critical to the climate of polar regions and,by extension,the mid-latitudes(North America,Eurasia,etc.).Remote sensing observations over the last 30 years have revealed that Arctic sea ice is melting rapidly,and it remains unclear whether this trend exceeds historical sea ice fluctuations.Resolving this uncertainty requires reconstructing a longer time series of Arctic sea ice variability.Many studies have attempted to reconstruct sea ice extent or sea ice density using proxy indicators.However,these studies mostly reflect changes in local ice coverage and lack information on broader Arctic sea ice variability.Using the high albedo of Arctic sea ice,we developed a statistical model of sea ice albedo-atmospheric circulation in order to reconstruct the spatial and temporal changes in Arctic summer sea ice areal extent over the past millennium.The results show that the spatial and temporal dynamics of the summer Arctic sea ice areal extent modelled by this method are in strong agreement with remote sensing observations.The reconstructed sea ice record shows that the rapid trend in ice melt over the last 30 years greatly exceeds historical fluctuations of sea ice area.This sea ice reconstruction method establishes the foundation for additional reconstructions of longer-term sea ice changes in the historical period.Furthermore,this reconstruction shows that the maximum ice coverage occurred in 1259 and encompassed an area of approximately 8.7 million km2,while the minimum occurred in 2003 and covered approximately 5.38 million km2.The difference between the minimum and maximum of Arctic sea ice areal extent is approximately 3.32 million km2,which is equivalent to a 38%reduction in coverage since peak extent occurred over 700 years ago.

关 键 词：北极地区 夏季 海冰面积 海冰反照率-大气环流模型 

分 类 号：P731.15[天文地球—海洋科学]