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Joint Study on Northern Environmental Change and Forecast

北方环境变化与预测联合研究

基本信息

批准号：
10045021
负责人：
FUKUDA Masami
金额：
$ 4.22万
依托单位：
Hokkaido Univeristy
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

1) Boreal Forest Fire Impact to Hydrological Condition in PermafrostIn 1999 July 8^<th>, prescribed forest fire experiment was conducted at Poker Creek Water shed in Alaska as to evaluate the impact of fire to permafrost condition. By the different degree of forest fire to permafrost. On the spot investigation thermal conductivity of uppermost humic layers was affected by fire degree. The reciprocal of the humic or arganic layer thickness and thermal conductivity after fire impact are major factor of deepening of active layer. During fire experiments, direct measurements of ground temperature were conducted by means of small size data loggers. At some location, temperature of frozen layer increased up to 50C degrees. This amount of creased temperature was not due to heat conduction but perorated melt water into the ground.2) Aerosol Emission by boreal forest fire experimentAt the site of FROST FIRE experiment and Barrow, Alaska long term monitoring of aerosol emission was conducted. As the result of measurement, at Barrow in winter and early spring, soot, black carbon, arsenic, and vanadium which were produced by industry were traced, and the occurrence of Arctic Haze was proofed by these materials. At Poker Flat, high amount of black carbon was detected indicationg the influence of boreal forest fire.3) Emission of green house gases from permafrostBy the chamber method on the ground surface, direct influence of forest fire to the emission of green house gas were measured at Poker Creek Water shed. The flux of carbon dioxide from permafrost after fire impact decreased. On the contrary, Methane flux increased indicating of additional thaw of permafrost.

1)1999年7月8日，在美国阿拉斯加州的扑克溪流域进行了森林火灾试验，以评估火灾对多年冻土水文条件的影响。<th>由不同程度的森林火灾到多年冻土。现场调查表明，火烧强度对最上层腐殖层的导热系数有一定的影响。腐殖酸层厚度与热传导系数的倒数是影响活性层深度的主要因素。在火灾实验中，通过小型数据记录仪直接测量地面温度。在某些地方，冻结层的温度上升到50摄氏度。2）北方森林火灾的气溶胶释放实验在阿拉斯加州的巴罗和霜冻火灾实验现场进行了气溶胶释放的长期监测。在巴罗的冬季和早春，通过对工业产生的煤烟、黑碳、砷和钒的测定，证实了北极灰霾的发生。3）多年冻土层绿色气体的排放利用地面气室法，在扑克溪流域测定了森林火灾对绿色气体排放的直接影响。火灾后冻土CO2释放通量降低。相反，甲烷通量增加，表明多年冻土的额外解冻。