Role of Snow Distribution Processes in Antarctic Sea Ice Mass Balance

北极和南极的海冰显示出一些重要的区别。几乎所有的南极海冰都是季节性的，在夏天消失。与多年的北极海冰相比，南极海冰通常更薄、更破碎、更粗糙，更容易被风和海浪移动。近年来，北极的冰层面积明显迅速减少，而南极洲的冰层却在不断扩大。雪在南极海冰物质平衡、海冰表面性质和海冰生态系统动力学中发挥着重要作用，但文献资料很少。据预测，由于大气变暖，南大洋的降水量将增加，但这种降水量增加在海冰质量平衡中可能起到的作用尚不清楚。最近的研究表明，海冰上雪的分布模式更多地归因于风的输送和雪的再沉积，而不是降水。此外，超过一半的降雪量可能会因为打开线索而消失。来自两个国际南极科考船的实地测量的组合将提出一些问题：1)雪深分布和冰面形态之间的空间关系是什么？2)雪深分布的统计描述能否作为冰类型或形态的函数？3)什么因素控制着吹雪的质量通量？4)地表粗糙度和地形如何控制吹雪的运输和沉积成变形冰和铅？5)海冰上雪的积累和分布是否可以量化为降水和冰条件的函数？这些问题是让我们了解南极海冰的特性及其在气候模型中的表现是非常有意义的。

Arctic and Antarctic sea ice exhibit some important differences. Almost all Antarctic sea-ice is seasonal, disappearing in summer. Antarctic sea-ice is usually thinner, more broken, rougher and more easily moved by the wind and waves than the multiyear Arctic pack. Arctic ice extent has been notably rapidly depleting over recent years, while Antarctic ice has been, if anything, expanding. Snow plays an important role but poorly documented role in Antarctic sea ice mass balance, sea ice surface properties and sea ice ecosystem dynamics. Precipitation over the Southern Ocean is predicted to increase as a consequence of atmospheric warming, but the role such a precipitation increase might play in sea ice mass balance is unclear. Recent work suggests that patterns of snow distribution on sea ice owes more to wind transport and re-deposition of snow than to precipitation. Also more than half of all snowfall may be lost to open leads. A combination of field measurements made from aboard two international Antarctic research cruises will set out with a number of questions in mind:1) What are the spatial relationships between snow depth distribution and ice surface morphology?2) Can a statistical description of the snow depth distribution be developed as a function of ice type or morphology?3) What factors control the mass flux of blowing snow?4) How does surface roughness and topography control blowing snow transport and deposition into deformed ice and leads?5) Can snow accumulation and distribution on sea ice be quantified as a function of precipitation and ice conditions?These questions are central to informing our knowledge of Antarctic sea-ice properties and their representation in climate models is of wide interest.