Monitoring and Modelling Lake Ice in Canada

加拿大的湖泊是景观的主要组成部分，在该国的大部分地区都有冰雪覆盖。湖冰对气候变率很敏感，近年来湖冰状况发生的变化主要是通过模拟和卫星数据记录到的，因为加拿大的地面观测网到1990年代末基本上已不复存在。卫星图像对于监测结冰/关闭的时间非常有用，但是，它目前在确定冰厚方面的用途有限。湖冰模式为研究冰期和厚度过程以及气候对湖泊冰盖的影响变化提供了一个合适的选择。湖泊的空间方面使建模和监测工作复杂化。在湖面上，或在邻近的湖泊上，冰盖的形成或消融可能不是均匀的。这是由于冰的形成和衰变受到湖泊大小和形状以及上覆积雪的影响，这可能导致冰的厚度在空间上发生变化。***本提案的总体目标是研究湖泊大小和形状对温带、亚北极和高北极气候区冰持续时间和厚度的影响，并在加拿大湖冰模式中解决这些影响。选定的湖泊位于哈里伯顿湖、丘吉尔湖和剑桥湾湖附近，是根据它们的可达性和长期监测的潜力选择的。将在每个地区建立自动化气象站，为模型输入提供当地气候条件，将安装冰厚传感器来监测冰的生长和衰减，整个冬季将手动测量雪和冰的厚度（现场），并将安装室外数码相机网络。多个摄像机将提供监测湖泊不同区域的冰况的能力，在这些区域，形状对冰雪的影响可能会有所不同。更大的湖泊也将利用现有的卫星数据进行监测。收集到的数据将用于改善积雪对模拟冰厚的影响，以及开发一种技术来解决湖泊大小对湖冰模型中结冰日期的影响。这项研究将在比卫星所能捕获的更小尺度上提供关于湖冰空间格局的新知识。它还将导致在湖泊形态测量和气候区域如何影响湖冰生长/衰减方面的湖冰模型的改进。这项研究对水文和气候学、生物学和湖泊学的研究人员在冰下栖息地和冰况变化对湖泊生态系统的影响有重要意义。最后，提高准确模拟冰厚的能力有助于改善娱乐和交通（如冰路）等领域的预测，特别是在未来气候情景的背景下。********

Canada's lakes are a dominant part of the landscape and experience ice cover in most regions of the country. Lake ice is sensitive to climate variability and changes occurring in lake ice regimes in recent years have been primarily noted through modelling and satellite data since the ground based observation network in Canada essentially ceased to exist by the late 1990s. Satellite imagery can be very useful for monitoring the timing of ice-on/off, however, it currently has limited use for determining ice thickness. Lake ice models present a suitable option for examining ice duration and thickness processes as well as climate influenced changes to the ice cover of lakes. Complicating both modelling and monitoring efforts are the spatial aspects of lakes. Ice cover may not form or decay uniformly across a lake surface, or across lakes in close proximity. This is due to the ice formation and decay being affected by the lake size and shape, as well as the overlying snow cover, which can result in spatially varying ice thickness.***The overall objective of this proposal is to investigate the effects of lake size and shape on ice duration and thickness across the temperate, subarctic and High Arctic climate regions and address these effects in the Canadian Lake Ice Model. The chosen lakes are near Haliburton ON, Churchill MB, and Cambridge Bay NU and were selected based on their accessibility and potential for long term monitoring. Automated weather stations will be set up in each region to provide local climate conditions for model input, ice thickness sensors will be installed to monitor ice growth and decay, snow and ice thickness will be measured manually throughout the winter (ON site), and a network of outdoor digital cameras will be installed. Multiple cameras will provide the ability to monitor ice conditions on different sections of the lakes where the shape influences on the snow and ice may differ. Larger lakes will also be monitored using available satellite data. The collected data will be used to improve the effects of snow cover on modelled ice thickness, as well as to develop a technique to address the effect of lake size on the ice-off dates within the lake ice model. ***This research will contribute new knowledge on spatial patterns of lake ice at a smaller scale than satellites can capture. It will also lead to improvements in the lake ice model with respect to the morphometry of lakes and how climatic regions affect the growth/decay of lake ice. This research is of interest to researchers in hydrology and climatology, as well as biology and limnology with respect to under ice habitat and changing ice conditions on the lake ecosystem. Finally, improving the ability to accurately model ice thickness can contribute to improved predictions in areas such as recreation and transportation (e.g. ice roads), especially in the context of future climate scenarios.********