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

极地地区气候变化和变异性影响的研究重点是极地海冰和气候系统之间的相互作用。特别是，三十多年来几乎每天覆盖极地地区的被动微波图像被用来确定海冰的密度和冰的运动。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量场和非地转运动场。此外，还提供了辐射平衡数据。统计模型被用来寻找时间和空间上的关联，这些关联可能提供对北极形成过程的洞察。 在高光谱图像分析领域，光谱混合模型的概念已经被用来获得地表特征的光谱特征。我们开发了适用于海冰集中的时间特征的概念，以便确定特定区域的冰覆盖的特定季节轮廓。我们现在正在将其应用于被动微波辐射计数据，以对由时间混合分析定义的特定区域的冰面面积减少年份进行排名，以确定过去八年的变暖存在哪些区域差异。这可以与世界气象组织按区域划分的类似温度排名进行比较，以深入了解大气变暖在区域差异中的作用。 第二个新的研究方向是通过观察不同地区每日冰异常的变化结构来分析春季融化的日期。在波弗特海和兰开斯特海湾地区的初步工作显示出希望。对ECMWF再分析辐射分量的时间变化进行了分析，海冰与海面太阳辐射通量和热辐射通量各分量的模式之间存在着有趣的联系。我们还研究了与融化开始相关的位势高度、温度、涡度等天气型的逐日演变，以评估与辐射异常有关的环流强迫。

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.