Multi-frequency microwave remote sensing of summer Arctic sea ice attributes as indicators of climate and biophysical processes

夏季北极海冰属性的多频微波遥感作为气候和生物物理过程的指标

• 批准号: RGPIN-2015-05540
• 负责人: Scharien, Randall
• 金额: $ 1.46万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633974
• 关键词: Multi; frequency; microwave; remote; sensing

In the last 30 years, summer Arctic sea ice extent has rapidly declined, leading to uncertainties regarding the fate of the Arctic marine environment and the coordination of Arctic stakeholders. There is now an entirely new Arctic ice pack dominated by thinner first-year ice (FYI) instead of thicker multiyear ice (MYI). The areal fraction of low albedo melt ponds on summer ice, termed pond fraction (PF), has increased due to fewer topographical controls on flooding extent over FYI compared to rough MYI. Several field studies point to the coupling of PF evolution to rates of shortwave radiation absorption, light transmittance, upper ocean warming, under-ice primary production, and atmosphere-ocean biogeochemical exchanges, including contaminants. Our understanding of local scale PF evolution and relationships with components of the Arctic marine environment is not matched at regional and greater scales. By extension, parameterizations of PF in large scale sea ice models, largely based on local scale observations of MYI, are inadequate for reliable regional and basin-wide forecasts of sea ice and climate conditions. At all scales the impact of intra-seasonal melting state variations on PF evolution and coupled processes are poorly understood. A robust means by which to monitor and assess the seasonal decay of summer ice and related biophysical processes is needed.

近30年来，北极夏季海冰面积迅速减少，给北极海洋环境的命运和北极利益攸关方的协调带来了不确定性。现在有一个全新的北极冰盖，由较薄的一年期冰（FYI）取代较厚的多年冰（MYI）。夏季冰面上低反照率融化池的面积分数，称为池塘分数（PF），由于FYI上对洪水范围的地形控制较少，与粗略的MYI相比有所增加。一些实地研究指出，PF的演变与短波辐射吸收率、透光率、上层海洋变暖、冰下初级生产和大气-海洋生物地球化学交换（包括污染物）的耦合。我们对局地尺度PF演变及其与北极海洋环境组分关系的理解在区域和更大尺度上是不匹配的。进一步地说，大尺度海冰模式中PF的参数化主要基于MYI的局地尺度观测，不足以对海冰和气候条件进行可靠的区域和全流域预报。在所有尺度上，季节性融化状态变化对PF演化和耦合过程的影响知之甚少。需要一种强有力的手段来监测和评估夏季冰的季节性衰变和相关的生物物理过程。