Role of Snow Distribution Processes in Antarctic Sea Ice Mass Balance

雪分布过程在南极海冰质量平衡中的作用

• 批准号: 1142075
• 负责人: Katherine Leonard
• 金额: $ 65.35万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1142075&HistoricalAwards=false
• 关键词: Role; Snow; Distribution; Processes; Antarctic

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.

北极和南极的海冰显示出一些重要的差异。几乎所有的南极海冰都是季节性的，在夏季消失。 南极海冰通常比北极多年形成的浮冰更薄、更破碎、更粗糙，更容易被风浪移动。 近年来，北极的冰面积明显迅速减少，而南极的冰面积却在扩大。雪在南极海冰质量平衡、海冰表面特性和海冰生态系统动力学中起着重要作用，但记录较少。 由于大气变暖，预计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发挥的作用尚不清楚。最近的研究表明，海冰上的雪分布模式更多地是由于风的输送和雪的再沉积，而不是降水。此外，超过一半的降雪可能会失去开放的线索。 结合两次国际南极考察船的实地测量，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是否可以作为冰的类型或形态的函数？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输送和沉积成变形冰和铅？5)海冰上的积雪和分布是否可以作为降水和冰况的函数进行量化？这些问题是我们了解南极海冰特性的核心，它们在气候模型中的代表性引起了广泛的兴趣。