Solidification effects of snowfall on sea-ice freeze-up: results from an onsite experimental study
Solidification effects of snowfall on sea-ice freeze-up: results from an onsite experimental study
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DOI：
10.1017/aog.2020.49
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发表时间：
2020-07
影响因子：
2.9
通讯作者：
T. Toyota;Takashi Ono;T. Tanikawa;P. Wongpan;Daiki Nomura
中科院分区：
文献类型：
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作者：
T. Toyota;Takashi Ono;T. Tanikawa;P. Wongpan;Daiki Nomura
尽管对于厚度足以容纳干雪的海冰，人们已经研究了雪在海冰生长过程中的作用，但对于薄海冰，由于观测困难，对雪的影响还没有引起足够的重视。雪泥的存在及其随后的冻结使观测变得复杂，地表热量收支可能对额外的冰厚度很敏感。根据观测结果和一维热力学模式，在日本北海道的Saroma-Ko泻湖进行了一个现场短期陆上快速海冰冻结试验，以考察降雪对薄海冰结构和表面热量收支的影响。我们发现，降雪有助于冰雪表层的固化，使冰层厚度与降雪量相当，并对晶体结构产生显著影响。基冰生长速率和湍流热通量没有受到显著影响，分别为3.1×10−8m S−1和3W m−2。这一发现可能证实了以往研究中在估计冰川产生率时忽略了雪的影响，并对从样本分析中重建生长历史具有一定的意义。
Abstract Although the effects of snow during sea-ice growth have been investigated for sea ice which is thick enough to accommodate dry snow, those for thin sea ice have not been paid much attention due to the difficulty in observing them. Observations are complicated by the presence of slush and its subsequent freeze-up, and the surface heat budget might be sensitive to the additional ice thickness. An onsite short-term land fast sea-ice freeze-up experiment in the Saroma-ko Lagoon, Hokkaido, Japan was carried out to examine the effects of snowfall on the structure and surface heat budget of thin sea ice, based on observational results and a 1-D thermodynamic model. We found that snowfall contributes to the solidification of the surface slush layer, contributing ice thickness that is comparable to the snowfall amount and affecting the crystal texture significantly. On the other hand, the basal ice growth rate and turbulent heat flux were not significantly affected, being <3.1 × 10−8 m s−1 and 3 W m−2, respectively. This finding may validate the omission in past studies of snow effect in estimating ice production rates in polynyas and has implications about the reconstruction of growth history from sample analysis.