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RECONSTRUCTION OF ALEUTIAN LOW ACTIVITIES FOR THE LAST 200 YEARS BY ICE CORE ANALYSES

通过冰芯分析重建阿留申岛过去 200 年的低度活动

基本信息

批准号：
09640517
负责人：
SHIRAIWA Takayuki
金额：
$ 1.79万
依托单位：
THE INSTITUTE OF LOW TEMPERATURE SCIENCE
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640517/
关键词：
ice core Paleoclimate Kamchatka Aleutian low カムチャツカ気候変化ロシア

项目摘要

Reconstruction of the Aleutian low activity was attempted by means of physical and chemical analyses of ice cores recovered from Ushkovsky Ice Cap, Kamchatka, Russia. Major ions and stable oxygen and hydrogen isotopes were measured for the upper 60 m of the ice cores. We found that NaィイD1+ィエD1, KィイD1+ィエD1, MgィイD12+ィエD1, CaィイD12+ィエD1, ClィイD1-ィエD1, and SOィイD24ィエD2ィイD12-ィエD1 are definitely influenced by volcanic activities because high peaks in these ions were observed at the same horizons where visible ash layers are present. In contrast, variations in NOィイD23ィエD2ィイD1-ィエD1 seem to be independent from volcanic ashes except for major volcanic event The fluctuations found in NOィイD23ィエD2ィイD1-ィエD1 are quasi-synchronous to those observed in stable oxygen and hydrogen isotopes which are known to fluctuate seasonally.By counting seasonallity in NOィイD23ィエD2ィイD1-ィエD1 and stable isotopes, ice core was converted into time series of annual mass balances after compensation with densification and thinning by flow. We found a signiricant positive correlation between reconstructed mass balances and total annual precipitation recorded at foot slope of the Ushkovsky volcano for the last 70 years This implies that the ice core is the proxy of annual precipitation in this area and provide proxy precipitation record for the last 500 years once the whole record (212 m) will be analyzed in future. It will be also possible for this ice cores to show DICE events since the major climate shift observed around mid-1970s in North Pacific Ocean is clearly recorded in the reconstructed mass balances as increasing precipitation.

通过对从俄罗斯堪察加半岛乌什科夫斯基冰盖回收的冰芯进行物理和化学分析，尝试重建阿留申群岛的低活动度。测量了冰芯上部 60 m 的主要离子以及稳定的氧和氢同位素。我们发现 NaィイD1+ィエD1、KィイD1+ィエD1、MgィイD12+ィエD1、CaィイD12+ィエD1、ClィイD1-ィエD1 和SOィイD24ィエD2ィイD12-ィエD1 肯定受到火山活动的影响，因为在存在可见灰层的同一地平线处观察到这些离子的高峰。相比之下，NOィイD23ィエD2ィイD1-ィエD1 的变化似乎与火山灰无关，除了重大火山事件。NOィイD23ィエD2ィイD1-ィエD1 中发现的波动与已知的稳定氧和氢同位素中观察到的波动准同步。季节性波动。通过计算季节性 NOィイD23ィエD2ィイD1-ィエD1和稳定同位素，冰芯经过流致密化和稀化补偿后转换为年质量平衡时间序列。我们发现重建的质量平衡与过去70年乌什科夫斯基火山脚坡记录的年降水总量之间存在显着的正相关性，这意味着冰芯是该地区年降水量的代理，并且在将来分析整个记录（212 m）时可以提供过去500年的代理降水记录。这些冰芯也有可能显示 DICE 事件，因为 1970 年代中期左右在北太平洋观察到的主要气候变化在重建的质量平衡中清楚地记录为降水增加。