Derivation of snow thickness information on sea ice using in-situ and satellite based multi-frequency polarimetric scatterometer and SAR data

利用现场和卫星多频偏振散射仪和 SAR 数据推导海冰积雪厚度信息

• 批准号: 238754-2011
• 负责人: Yackel, John
• 金额: $ 1.6万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=547081
• 关键词: Derivation; snow; thickness; information; sea

The recent and rapid reduction in Arctic sea ice has received considerable scientific and media attention during the past decade. This decrease has occurred to both its seasonal extent and to its thickness distribution. Modelling studies suggest that the long-term declining trend for both the extent and thickness of Arctic sea ice will continue for at least the next several decades due to an enhanced greenhouse effect resulting from the atmospheric build-up of anthropogenic produced gases. Global climate models participating in the latest Intergovernmental Panel on Climate Change - Fourth Assessment Report (IPCC-AR4) show that a transition to a summertime ice-free Arctic could occur both abruptly and earlier than previously anticipated. However, the sea ice cover remains highly variable from year-to-year within respect to its extent and thickness distribution owing to large scale atmospheric circulation pattern changes which operate over a continuum of time and space scales throughout the Arctic. These atmospheric circulation changes manifest to deposit spatially varying amounts of precipitation in the form of snow accumulation once the sea ice has formed, however, our ability to measure and quantify these amounts using optically based satellite remote sensing techniques is severely limited owing to cloud cover and 24-hour darkness during much of the fall and winter. The snow cover on sea ice is a critical component of snow/sea ice system because it controls the ice thickness and melt behaviour of the ice. As a result, it also largely controls the mechanical properties of the ice such as ice strength and break-up potential. This research will use all-weather imaging microwave remote sensing data acquired from both the ice surface and satellites along with snow covered thermodynamic sea ice and microwave scattering models fed with in situ collected snow and sea ice property data. The expected results will permit an estimation the snow cover characteristics (thickness distribution, snow water equivalent, liquid water content) at various times during the spring transition such that an improved understanding of the role of snow on sea ice can be assessed towards determining its role in the interannual variability in Arctic sea ice extent and thickness.

在过去的十年中，北极海冰的最近和迅速减少受到了科学和媒体的关注。这种减少的季节性范围和厚度分布都发生了。建模研究表明，由于人为产生的气体的大气积累，至少在接下来的几十年中，北极海冰范围和厚度的长期趋势都将持续至少几十年。参与最新政府间气候变化小组的全球气候模型 - 第四次评估报告（IPCC-AR4）表明，向夏季无冰北极的过渡可能会突然出现，并且比以前预期的要早。然而，由于大规模大气循环模式变化，海冰覆盖层的程度和厚度分布在其范围和厚度分布的情况下仍然很大，在整个北极的时间和空间尺度上都可以运行。这些大气循环变化表现为在海冰形成一旦形成海冰，以积雪的形式表现出空间变化的降水量，但是，我们在秋季和冬季的大部分时间内使用基于光学的卫星遥感技术测量和量化这些量的能力严重限制了云和24小时黑暗。海冰上的雪覆盖是雪/海冰系统的关键组成部分，因为它可以控制冰的冰厚度和融化行为。结果，它还在很大程度上控制了冰的机械性能，例如冰强度和破裂潜力。这项研究将使用从冰层和卫星中获取的全天候成像微波遥感数据，以及雪覆盖的热力学海冰和微波散射模型，并用原位收集的雪和海冰特性数据喂养。预期的结果将允许在春季过渡期间的不同时间估算雪覆盖特征（厚度分布，雪水等效，液态水含量），以便可以评估对雪对海冰的作用的了解，以确定其在北极海上冰冰范围和厚度的年度变异性中的作用。