摘要
铁是地壳中丰度较高的元素之一,然而在全球海洋中却存在大面积缺铁的"高营养盐,低叶绿素"(HNLC)海域,因此海洋中铁是一种相对缺乏的元素。铁可以通过影响浮游植物对碳的固定,降低大气CO_(2)的浓度,进而影响到全球气候变化。因此在近几十年来,铁循环是目前地球科学领域的研究热点。冰冻圈作为全球铁循环的重要组成部分之一,其中冰川、冰盖、积雪、冰山与海冰等是其主体,其不仅可以记录大气沉降铁,同时又能向海洋中输送铁,是全球铁循环的重要环节。本文对极地和青藏高原雪冰中铁的历史变化规律及气候意义进行了综述,总结了雪冰中大气沉降铁的现状及存在的问题,归纳了雪冰中铁的实验室分析方法。针对该领域目前研究上的空白和热点,对雪冰中铁的未来发展发向和需要重点关注的部分进行了展望。
The iron(Fe)has a high crustal abundance(ca.5.6%)and its compounds make up a significant proportion of the Earth’s rocks and soils but its low solubility dictates that dissolved iron concentrations in seawater are typically sub-nanomolar.Therefore,there are large areas of"High-Nitrate,Low Chlorophyll"(HNLC)in the global ocean.Fe is considered the main limiting nutrient of phytoplankton growth in HNLC sea.Fe from different sources can affect global climate change by affecting marine primary production,so the biogeochemical cycle of Fe has become a research hot topic of geosciences in recent decades.The cryosphere is one of the key components of the Earth System,and the ice sheet,glacier,snow and sea ice are important component of the cryosphere,which can not only record atmospheric Fe deposition,but also transport Fe into the ocean.Therefore,the cryosphere is an important part of the global Fe cycle.In this paper,we reviewed the Fe record in polar and alpine glacier.The ice cores from polar and alpine glacier,which preserve detailed climate records in their stratigraphy,provide a continuous archive to reconstruct past atmospheric Fe fluxes.Based on the Fe records in Antarctica deep ice cores,we observe large glacial-interglacial contrasts in Fe deposition,which reflects strongly changing South Hemisphere conditions.However,we found the Fe fluxes in the same period(e.g.Last Glacial Maximum)in different deep ice cores in Antarctica are different,which we infer influenced by the different preliminary treatments and analysis method.Therefore,we also investigate the analysis methods of Fe in snow and ice of polar regions,and we think the most appropriate method to determine the iron concentration in the snow and ice is the inductive coupled plasma mass spectrometry(ICP-MS).We suggested that several aspects should be highlighted in the future studies.Studies regarding the reconstruction of atmospheric Fe in the alpine ice cores should be given more attentions.The source and mineral form of iron in alpine snow and ice will provide a basis for similar research in polar regions.Besides,DFe in the snow and ice is scarce in polar regions,the relationship between DFe and marine primary production is important for the iron study in ice core in polar regions.Studies regarding the source of atmospheric Fe in the ice core as well as the potential application of mineralogical characteristics and Fe isotope in snow and ice are also recommended.
作者
刘科
侯书贵
庞洪喜
吴霜叶
张王滨
邹翔
于金海
LIU Ke;HOU Shugui;PANG Hongxi;WU Shuangye;ZHANG Wangbin;ZOU Xiang;YU Jinhai(School of Geography and Ocean Science,Nanjing University,Nanjing 210023,Jiangsu;School of Oceanography,Shanghai Jiao Tong University,Shanghai 200240;Department of Geology,University of Dayton,Dayton,Ohio 45469)
出处
《第四纪研究》
CAS
CSCD
北大核心
2021年第3期792-803,共12页
Quaternary Sciences
基金
国家自然科学基金项目(批准号:91837102、41830644和41771031)
自然资源部国家海洋局极地考察办公室2020年度极地科学协同创新平台项目(批准号:CXPT2020012)
江苏省“333高层次人才工程”项目(批准号:BRA2020030)共同资助。
关键词
雪冰
铁
大气沉降
南极
北极
snow and ice
Fe
atmospheric deposition
Antarctica
Arctic
