Derivation of snow thickness information on sea ice using in-situ and satellite based multi-frequency polarimetric synthetic aperture radar data

利用现场和卫星多频极化合成孔径雷达数据推导海冰积雪厚度信息

• 批准号: 305482-2011
• 负责人: Yackel, John
• 金额: $ 1.09万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Northern Research Supplement
• 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=548434
• 关键词: Derivation; snow; thickness; information; sea

Considerable attention has focused on the satellite measured decline of sea ice extent in the Arctic Ocean over the past 10+ years. Sea ice makes up approximately 11% of the Earth's surface area and is a critical variable in the global radiation and energy balances and to determining the Earth's response to climate change. The snow cover on sea ice is an important physical variable that plays a central role in mass and energy exchange across the ocean-sea ice-atmosphere interface. Because of the high albedo of snow, the shortwave radiative exchange dominates the sea ice-albedo feedback mechanism during the spring transition season. The onset of spring melt and the eventual formation of liquid water melt ponds on the surface of the sea ice cause rapid decreases in the surface albedo, and as such, cause an increase in the rate of ice melt. Spring melt on Arctic sea ice is highly variable in both space and time and is largely governed by the timing and magnitude of snow thickness on the sea ice prior to sufficient atmospheric warming. Information of snow on sea ice is scarce. This is because of the inherent difficulties in measuring snow distributions remotely and/or the lack of representativeness of High Arctic climate and precipitation reporting stations. Historical data on snow thickness distributions and their relationship to types of sea ice are also rare. Evidence from both observational and modeling studies indicate that snow on sea ice plays a central role in the interaction of visible and microwave energy at the surface and within the volume. My research addresses a number of key questions to understand the inter-relationship between the visible and microwave EM interactions of snow covered sea ice using a combination of surface and satellite based remote sensing data during the spring melt transition period. Observations of snow thickness will be collected annually from both a cold environment laboratory setting and in-situ High Arctic environments coincident with other climate and sea ice measurements along with surface and satellite based remote sensing data for the purpose of quantifying the role snow plays in manifesting sea ice extent and thickness at a variety of spatial and temporal scales.

在过去的十多年中，大量关注的重点是卫星测量了北极海洋冰量的下降。海冰约占地球表面积的11％，是全球辐射和能量平衡的关键变量，并确定地球对气候变化的反应。海冰上的雪覆盖是一个重要的物理变量，它在跨大洋冰冰界的质量和能量交换中起着核心作用。由于雪的反照率很高，短波辐射交换在春季过渡季节中占据了海冰 - 阿尔贝多的反馈机制。弹簧熔体的发作以及液态水在海冰表面的最终形成导致表面反照率的快速减少，因此导致冰融化的速率增加。在空间和时间上，北极海冰上的弹簧融化都有很大变化，并且在充足的大气变暖之前，在很大程度上受海冰上的雪厚的时间和幅度支配。海冰上的雪的信息很少。这是因为远程测量雪分布的固有困难和/或缺乏高北极气候和降水报告站的代表性。关于雪厚分布及其与海冰类型的关系的历史数据也很少见。观察性研究和建模研究的证据表明，海冰上的雪在表面和体积内的可见和微波能的相互作用中起着核心作用。我的研究解决了许多关键问题，以了解在春季熔体过渡期间，使用表面和基于卫星的遥感数据的组合，可见的和微波EM相互作用之间的相互关系覆盖了海冰。每年将从冷环境实验室环境和现场高北极环境中收集雪厚度的观察结果，以及与其他气候和海冰测量相一致的，以及基于表面和卫星的遥感数据，以量化积雪在各种空间和时间尺度上表现出海冰的作用，并在各种空间和时间范围内表现出厚度。