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RECONSTRUCTION OF CLIMATE AND ATMOSPHERIC TRANSPORT BY MEANS OF ICE CORE ANALYSES IN THE NORTH PACIFIC

通过冰芯分析重建北太平洋的气候和大气输送

基本信息

批准号：
16403005
负责人：
SHIRAIWA Takayuki
金额：
$ 6.21万
依托单位：
Research Institute for Humanity and Nature (2005)Hokkaido University (2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

项目摘要

We analyzed the ice core drilled at Mt.Wrangell in 2004. The analyses were made for the upper 100m of the 217-m long ice core. They are hydrogen isotope ratio (0-50m), major ions (0-50m), dust concentration (0-80m), X-ray density (0-100m) and tritium (0-50m). Trace elements were also measured for the Mt.Logan ice core which we drilled in 2002. Following results are obtained by this research project :1.Clear seasonal cycles are found for the upper 50m of the ice core in the cases of hydrogen isotope ratio, dust and tritium concentrations. The peaks appeared in summer for delta D and spring for the dust and tritium concentrations.2.Standard deviation in the X-ray density variations are negatively related with delta D suggesting that the high density variations occur in spring-summer period when snow falls rather intermittently.3.Concentration in dust becomes higher in spring and lower in the other periods. It is also found that the dust concentration has been increasing since 2000, which coincides with observation of dust falls in Japan.4.Tritium concentration in the Wrangell ice core shows a beautiful seasonal cycle having the highest peak in spring. This is due to the so-called "Stratosphere-Troposphere Exchange" in air mass and the concentration can be a promising indication of atmospheric disturbances in spring.5.Sodium flux is positively correlated with Pacific Decadal Oscillations suggesting the atmospheric-oceanic interaction in the North Pacific.6.Annual Iron fluxes during the period 1980-2000 in the Logan ice core were varying from several μg/square m to 80μg/square m. The source of the iron can be ascribed to Asian dust and the nearby volcanoes.7.Annual accumulation rates both in the Wrangell ice core and the Logan ice core showed clear negative relationship for the last 100 years, suggesting that the PDO has impacted mountain precipitation significantly.

我们分析了2004年在Mt.Wrangell钻取的冰芯。分析是针对217米长冰芯的上部100m进行的。它们是氢同位素比（0-50m）、主要离子（0-50m）、灰尘浓度（0-80m）、X射线密度（0-100m）和氚（0-50m）。我们还对2002年钻探的Mt.Logan冰芯进行了微量元素测量。本研究项目获得了以下结果： 1.在氢同位素比、灰尘和氚浓度的情况下，冰芯上部50m发现了明显的季节循环。 δ D 峰值出现在夏季，沙尘和氚浓度峰值出现在春季。2.X 射线密度变化的标准差与δ D 负相关，表明高密度变化出现在春夏季节，降雪间歇性较大。3.沙尘浓度春季较高，其他时期较低。研究还发现，自2000年以来，沙尘浓度一直在增加，这与日本沙尘暴的观测结果吻合。4.兰格尔冰芯的氚浓度呈现出美丽的季节周期，春季达到最高峰值。这是由于气团中所谓的“平流层-对流层交换”，其浓度可以作为春季大气扰动的一个有希望的指示。5.钠通量与太平洋年代际振荡呈正相关，表明北太平洋的大气-海洋相互作用。6.洛根冰芯中 1980-2000 年期间的年度铁通量从几微克/平方米到几微克/平方米不等。 80微克/平方米。铁的来源可归因于亚洲尘埃和附近的火山。7.兰格尔冰芯和洛根冰芯的年积累率在过去100年中表现出明显的负相关关系，表明PDO对山区降水有显着影响。