| 摘要: |
| 西格陵兰位于北极-北大西洋地区，其海洋环境演变受西格陵兰洋流中冷、暖水团的显著影响。本文运用主成分分析方法对西格陵兰Disko湾DA06-139G孔沉积物中主要硅藻属种进行研究，试图揭示5000a BP以来西格陵兰洋流中冷、暖水团强度变化对研究区海洋环境的影响。5000-3800a BP期间，东格陵兰寒流携带的极地冷水团强度较弱，而北大西洋暖水团势力较强，Disko湾地区海洋环境较为温暖。3800-2000a BP期间，西格陵兰洋流中极地冷水团势力呈现阶段性增强，此时Disko湾地区气候缓慢转冷，海冰覆盖面积逐渐增加。2000a BP以后，特别是650a BP之后，样品在主成分轴一上的得分显著增高，表明Disko湾气候明显变冷，来自东格陵兰寒流的极地冷水团强度显著增强。Disko湾中晚全新世以来的硅藻记录及样品在主成分轴一上的得分所指示的极地冷水团的强度变化与格陵兰冰芯温度及海冰变化等具有较好的一致性，说明研究区海流特征与大气温度、海冰等环境要素密切相关。 |
| 关键词: 中晚全新世 西格陵兰洋流 Disko湾 硅藻 |
| DOI：10.11693/hyhz20160500101 |
| 分类号: |
| 基金项目:国家自然科学基金项目，41302134号，41406209号；南北极环境综合考查与评估专项，CHINARE2016-03-02号；宁波大学学科项目，xkl13d210号。 |
附件 |
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| IMPACT OF COLD WATERS ON THE DISKO BUGT, WEST GREENLAND DURING THE MID-TO LATE-HOLOCENE |
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LI Dong-Ling1, SHA Long-Bin1, LIU Yan-Guang2, JIANG Hui3, WU Yan-Ni1
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1.Department of Geography & Spatial Information Techniques, Ningbo University, Ningbo 315211, China;2.Key Laboratory of Marine Sedimentology and Environmental Geology, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China;3.Key Laboratory of Geographic Information Science, East China Normal University, Shanghai 200062, China
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| Abstract: |
| West Greenland is located in Arctic-North Atlantic area,of which climatic and hydrographical conditions are strongly influenced by changes in the relative strengths of two components of the West Greenland Current:the cold polar waters from the East Greenland Current (EGC) and warmer Atlantic water from the Irminger Current (IC).A high-resolution diatom record was reconstructed in Core DA06-139G located in Disko Bugt,West Greenland,showing the variability of the cold polar waters over the past 5000 years by principal component analysis (PCA).A relatively warm period with increased influence of Atlantic warm water occurred at the interval of 5000-3800a BP,as a result of a weakening of the cold polar water in Disko Bugt.During 3800-2000a BP,the influence of cold polar waters from the EGC increased in the Vaigat Strait and further led to a cold condition that enhanced sea-ice cover.After 2000a BP,sample scores on the first PCA axis are much higher than the one earlier,particularly so after ca.650a BP,indicating a strengthened impact of the cold polar waters and colder hydrographic conditions during the Little Ice Age.Furthermore,the good coherence between diatom and PCA results,and temperature reconstruction from Greenland ice core suggests that changes in the strength of the West Greenland Current is correlated with air temperature and sea-ice concentration in West Greenland. |
| Key words: Mid-to late-Holocene the West Greenland Current Disko Bugt Diatom |
