Atmosphere‐to‐snow‐to‐firn transfer studies of HCHO at Summit, Greenland
Atmosphere‐to‐snow‐to‐firn transfer studies of HCHO at Summit, Greenland
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格陵兰峰会上甲醛从大气到雪到雪的转移研究
DOI：
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发表时间：
1999
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影响因子：
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通讯作者：
R. Bales
中科院分区：
文献类型：
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作者：
M. Hutterli;R. Röthlisberger;R. Bales
1996年6月在格陵兰萨米特对雪、积雪、大气和积雪开放孔隙空间（积雪空气）中的甲醛（HCHO）进行了测量，结果表明，最上层的雪层是甲醛的来源。新雪中的甲醛浓度高于与大气浓度平衡的浓度，导致甲醛在降雪后几天至几周内脱气。积雪空气中甲醛的最大浓度为1.5-2.2 ppbv，而地表以上1米处的平均大气甲醛浓度为0.23 ppbv。雪中的HCHO表观通量是光化学建模预测的0.1 ppbv大气浓度与测量值之间差异的合理解释。在年平均温度下，积雪较深处的HCHO与对流层较低处的HCHO浓度接近平衡。因此，冰中的HCHO实际上可能通过温度依赖的分配系数与多年平均大气浓度线性相关。
Formaldehyde (HCHO) measurements in snow, firn, atmosphere, and air in the open pore space of the firn (firn air) at Summit, Greenland, in June 1996 show that the top snow layers are a HCHO source. HCHO concentrations in fresh snow are higher than those in equilibrium with atmospheric concentrations, resulting in HCHO degassing in the days to weeks following snowfall. Maximum HCHO concentrations in firn air were 1.5–2.2 ppbv, while the mean atmospheric HCHO concentration 1 m above the surface was 0.23 ppbv. Apparent HCHO fluxes out of the snow are a plausible explanation for the discrepancy between the 0.1 ppbv atmospheric concentration predicted by photochemical modeling and the measurements. HCHO in deeper firn is near equilibrium with the lower tropospheric HCHO concentration at the annual average temperature. Thus HCHO in ice may in fact be linearly related to multi‐year average atmospheric concentrations through a temperature dependent partition coefficient.