Amidst changing seasonal snow-covered periods and extents in northern high latitude regions, winter CH₄ oxidation is susceptible to drastic climate change, all of which modulates an accurate assessment of regional carbon balance. The importance of winter CH₄ oxidation to the soils in these regions has previously been recognized; in this study, concentrations of CH₄ and ²²²Rn were observed in the snowpack and underlying cold temperate soils during the winters of 1995/96 and 1996/97. These observations were carried out in order to 1) validate the ²²²Rn tracer as a proxy for variations in CH₄ diffusivity within a snowpack containing many seasonal ice lenses, and to 2) estimate winter CH₄ oxidation through the snowpack to the soils. Winter CH₄ oxidations estimated by snow density (method 1); using the ²²²Rn tracer under steady (method 2) and non-steady (method 3) conditions; and using a static chamber (method 4) during the winter of 1996/97 yielded 16.7 ± 6.3; 8.2 ± 2.9; 9.8 ± 7.4; and 4.5 ± 2.5 mg CH₄–C m⁻², respectively. These results suggest that contributions from average CH₄ oxidation represent 23.3% (range: 12.7–35.1%) of the annual CH₄ oxidation into cold temperate soils. Wintertime CH₄ oxidation significantly reflects temporal variation in the snowpack, demonstrating that soil temperature depends on snow cover, and that a threshold snow depth of 40 cm does not prevent, but rather promotes, atmospheric CH₄ oxidation through snowpack to the soils. These findings demonstrate that the ²²²Rn tracer was useful for estimating winter CH₄ diffusivity and oxidation, using a one-dimensional vertical diffusion box model in cold temperate soils in Japan during multiple snow-covered seasons.

在北部高纬度地区季节性积雪覆盖时间和范围不断变化的情况下，冬季 CH ₄氧化容易受到剧烈气候变化的影响，所有这些都会调节区域碳平衡的准确评估。先前已经认识到冬季 CH ₄氧化对这些地区土壤的重要性；在这项研究中，在 1995/96 和 1996/97 冬季期间，在积雪和下伏的寒温带土壤中观察到CH ₄和²²² Rn 的浓度。进行这些观察是为了 1) 验证²²² Rn 示踪剂作为 CH ₄变化的代理包含许多季节性冰透镜的雪堆内的扩散率，以及 2) 估计冬季 CH ₄氧化通过雪堆到土壤。通过雪密度估算的冬季 CH ₄氧化（方法 1）；在稳定（方法 2）和非稳定（方法 3）条件下使用²²² Rn 示踪剂；并在 1996/97 冬季使用静态室（方法 4）产生 16.7 ± 6.3；8.2±2.9；9.8±7.4；和 4.5 ± 2.5 mg CH ₄ –C m ^-2，分别。这些结果表明，平均 CH ₄氧化的贡献占每年 CH ₄氧化进入冷温带土壤的23.3%（范围：12.7-35.1%）。冬季 CH ₄氧化显着反映了积雪的时间变化，表明土壤温度取决于积雪，并且 40 cm 的阈值雪深不会阻止，而是促进大气 CH ₄通过积雪氧化到土壤。这些发现表明，²²² Rn 示踪剂可用于估计冬季 CH ₄扩散率和氧化，在多个雪覆盖季节期间使用日本寒冷温带土壤中的一维垂直扩散箱模型。