Analysis of Climate - Sea Ice Interactions in the Polar Basin using Remote Sensing Imagery and Atmospheric Diagnostics

利用遥感图像和大气诊断分析极地盆地的气候-海冰相互作用

• 批准号: 8454-2012
• 负责人: LeDrew, Ellsworth
• 金额: $ 1.97万
• 依托单位: University of Waterloo
• 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=568591
• 关键词: Analysis; Climate; Sea; Ice; Interactions

Research on the impacts of climate change and variability in polar regions focuses on the interactions between the polar sea ice and climate systems. In particular, more than thirty years of passive microwave imagery of almost daily coverage of the polar regions is used to determine sea ice concentration and ice motion. Upper air reanalysis data from the European Centre for Medium-Range Weather Forecasts are used to determine synoptic patterns of geopotential height and temperature as well as derived fields of vorticity and ageostrophic motion. In addition, radiation balance data are available. Statistical models are used to find associations in time and space that may provide insight into the formative processes in the Arctic. From the field of hyperspectral image analysis, the concept of the spectral mixture model has been used to derive spectral signatures of surface characteristics. We have developed the concept to apply to temporal signatures of sea ice concentration in order to identify specific seasonal profiles of ice coverage for specific regions. We are now applying this to the Passive Microwave Radiometer data to rank the years of decreasing ice extent for specific regions defined by the temporal mixture analysis to determine what regional disparities exist in the warming of the past eight years. This can be compared with similar WMO ranking of temperatures by region to provide insight into the role of atmospheric warming in the regional disparities. A second new line of inquiry is analysis of the date of spring melt by looking at the change in the variance structure of the daily ice anomalies in various regions. Initial work in the Beaufort Sea and Lancaster Sound areas show promise. The analysis of the temporal change in variance is also applied to the data for the radiation components from the ECMWF reanalysis and there are interesting associations between sea ice and the patterns of the components of the solar and thermal radiation fluxes for the surface. We have also examined the daily progression of synoptic patterns of geopotential height, temperature, vorticity etc. associated with the onset of melt to assess the circulation forcing in conjunction with the radiation anomalies.

关于极地地区气候变化和变率影响的研究侧重于极地海冰与气候系统之间的相互作用。特别是，超过三十年的被动微波图像几乎每天覆盖极地地区被用来确定海冰浓度和冰的运动。 来自欧洲中期天气预报中心的高空再分析数据被用来确定位势高度和温度的天气模式以及导出的涡度场和非地转运动场。 此外，还有辐射平衡数据。统计模型被用来寻找在时间和空间上的关联，这可能有助于深入了解北极的形成过程。 从高光谱图像分析领域，光谱混合模型的概念已被用于获得表面特征的光谱特征。 我们已经开发的概念，适用于海冰浓度的时间特征，以确定特定区域的冰覆盖的特定季节性配置文件。 我们现在将其应用于被动微波辐射计数据，对由时间混合分析定义的特定区域的冰范围减少的年份进行排名，以确定过去八年变暖中存在哪些区域差异。 这可以与世界气象组织按区域对气温进行的类似排名进行比较，以深入了解大气变暖在区域差异中的作用。 第二个新的调查路线是通过观察不同地区每日冰异常的方差结构的变化来分析春季融化的日期。 在博福特海和兰开斯特湾地区的初步工作显示出希望。 方差的时间变化的分析也适用于从ECMWF再分析的辐射分量的数据，有有趣的海冰和太阳和热辐射通量的组件的模式之间的关联的表面。 我们还研究了与融化开始有关的位势高度、温度、涡度等天气型的日进程，以评估与辐射异常有关的环流强迫。