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Reconstruction of glacial-interglacial variations of greenhouse gases from a Greenland deep ice core, NGRIP

从格陵兰深冰芯重建冰期-间冰期温室气体变化，NGRIP

基本信息

批准号：
13304035
负责人：
NAKAZAWA Takakiyo
金额：
$ 31.2万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13304035/
关键词：
Ice core Greenland North GRIP Greenhouse gas Isotope Glacial period Interglacial period Global cycle

项目摘要

In order to reconstruct variations of atmospheric CH_4, N_2O, CO_2 and O_2 concentrations, δ^<15>N of N_2, δ^<18>O of O_2, and air content for the last 130 Kyrs, we analyzed the North-GRIP deep ice core from Greenland using a wet air extraction technique. We also determined ice age and age differences between ice and occluded air based on the results of δ^<18>O of ice and an accumulation model. After correcting for a gravitational effect occurred due to molecular diffusion in firn, detailed temporal variations of all the abovementioned factors were deduced. Furthermore, we also discussed the similarity and differences between variation histories of all factors in north and south polar regions, by comparing the results obtained from the North-GRIP core and the Dome Fuji deep ice core, Antarctica. Especially interesting results derived in this study are that 1.the CH4 concentration was always higher in the north polar region in the south polar region, and those concentration differences … More depended on temperature, except for Holocene, 2.the CO_2 concentrations from the North-Grip core were apparently higher than those from the Dome Fuji core, suggestion that CO2 was newly produced by reacting with impurities during storage of air in ice in Greenland, 3.the N_2O concentrations from the North-Grip and Dome Fuji ice cores were fairly stable for Holocene, but quite variable in the glacial period, 4.the O2 concentrations from the North-Grip and Dome Fuji ice cores were extremely low, suggesting that the process of air occlusion into ice at the bottom of firn is very complex, and 5.that temporal variations of air content from both cores were similar to each other, but such variations are in conflict with our present knowledge, which may be related to incident solar radiation. By analyzing the temporal variations of CH4 concentration differences obtained from the North-Grip and Dome Fuji ice cores using a 3-box model consisting of northern and southern high latitudes and low latitude, we also succeeded in elucidating where was responsible for the north-south concentration differences over the glacial interglacial period. Less

为了重建近130 Kyrs来大气CH_4、N_2O、CO_2和O_2浓度、N_2的δ^<15>N、O_2的δ^ O<18>和空气含量的变化，我们利用湿空气提取技术分析了格陵兰北部GRIP深冰芯。根据冰的δ^ O和积累模型的结果，我们还确定了冰的年龄和冰与闭塞空气之间的年龄差异<18>。在对由于分子扩散引起的重力效应进行校正后，推导出了上述各因子的详细时间变化。通过对南极北极GRIP冰芯和南极Dome Fuji深冰芯的观测结果的比较，讨论了南北两极各因子变化历史的相似性和差异。研究结果表明：1.北极区的甲烷浓度高于南极区，而南极区的甲烷浓度高于北极区。 ...更多信息除全新世外，其他时间均取决于温度。2. North-Grip冰芯的CO_2浓度明显高于Dome Fuji冰芯，表明格陵兰冰中空气储存过程中与杂质反应新产生的CO_2。3. North-Grip冰芯和Dome Fuji冰芯的N_2O浓度在全新世相当稳定，但在冰期变化很大。4.北极冰核和富士冰穹冰芯的O_2浓度极低，表明空气在雪底的吸积过程非常复杂; 5.两个冰芯的空气含量的时间变化相似，但这种变化与我们现有的知识相矛盾，这可能与入射太阳辐射有关。通过分析从北握和圆顶富士冰芯获得的CH 4浓度差异的时间变化，使用一个由北方和南方高纬度和低纬度组成的三箱模型，我们也成功地阐明了在冰期间冰期南北浓度差异的原因。少