Modelling of superimposed ice formation during the spring snowmelt period in the Baltic Sea
Modelling of superimposed ice formation during the spring snowmelt period in the Baltic Sea
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DOI：
10.3189/172756406781811277
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发表时间：
2006
影响因子：
2.9
通讯作者：
B. Cheng;T. Vihma;R. Pirazzini;M. Granskog
中科院分区：
文献类型：
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作者：
B. Cheng;T. Vihma;R. Pirazzini;M. Granskog
摘要在2004年早期融化季节，对波罗的海波特尼亚海湾陆上海冰及其积雪的发展进行了为期4周的监测。在此期间，大约90%的雪层转化为叠加冰，其余的则升华。采用一维热力学冰雪模式对这一过程进行了模拟。模拟的积雪融化和叠加冰的增长与观测结果一致，但叠加冰的净积累量被略微高估了。计算复冻时间变化的误差可能是由于外部强迫的不确定性和模式中降雪过程的简化所致。模拟的积雪厚度对大气强迫很敏感，当反照率被参数化为地表温度的函数时，这种影响被放大。在没有这种反馈的灵敏度测试中，反照率参数化不准确的直接影响很小。参数化长波辐射的误差对模拟的夜间雪面温度至关重要，但对春季融化期间的物质平衡没有太大影响。
Abstract Development of landfast sea ice and its snow cover was monitored in the Gulf of Bothnia, Baltic Sea, for a period of 4 weeks during the early melt season of 2004. During this period, approximately 90% of the snow layer was transformed into superimposed ice, while the rest sublimated. A one-dimensional thermodynamic snow/ice model was used to simulate this process. The modelled snowmelt and superimposed ice growth were consistent with the observations, but the net accumulation of superimposed ice was slightly overestimated. The errors in calculation of temporal variations of the refreezing were probably due to the uncertainties in the external forcing and simplification of snow processes in the model. The modelled snow thickness was sensitive to the atmospheric forcing, and the influence was amplified when the albedo was parameterized as a function of surface temperature. In the sensitivity tests without this feedback, the direct effect of the inaccuracy in the albedo parameterization was minor. Errors in the parameterized longwave radiation were critical for the modelled snow surface temperature during night-time, but did not have a large effect on the mass balance during this spring melt period.