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: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=590493
• 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.

在过去30年中，夏季北极海冰范围迅速减少，导致北极海洋环境的命运和北极利益攸关方的协调存在不确定性。现在有一个全新的北极冰盖，主要是较薄的第一年冰（FYI），而不是较厚的多年冰（MYI）。夏季冰面上的低CO2融化池塘的面积分数，称为池塘分数（PF），增加了由于地形控制洪水范围FYI相比，粗糙MYI。一些实地研究指出，PF演变的耦合率的短波辐射吸收，透光率，上层海洋变暖，冰下初级生产，大气-海洋生物地球化学交换，包括污染物。我们对当地尺度的PF演变和与北极海洋环境组成部分的关系的理解在区域和更大的尺度上是不匹配的。推而广之，PF在大尺度海冰模式，主要是基于当地尺度观测MYI的参数化，是不足以可靠的区域和流域范围内的海冰和气候条件的预测。在所有尺度上，季节内融化状态变化对PF演变和耦合过程的影响知之甚少。需要有一种强有力的手段来监测和评估夏季冰的季节性衰减和相关的生物物理过程。