Daily Canadian Snow Inland Ice Cover Synthesis Maps

Purpose: This map is intended for scientific applications requiring timely information on snow cover presence at relatively high spatial resolution and validated against Canadian insitu snow course data sets. The restriction to a binary snow/no-snow classification will result in a slight increase in disagreement (up to 20 per cent) with field snow course data during the melt period with higher agreement (~90 per cent) outside this period. However, at least half of this disagreement is traceable to random errors that will tend to cancel out when the data set is aggregated spatially. The residual errors are land cover dependent typically. Users who wish to use this snow cover information to drive other models should take this error structure into consideration. This map should not be used for operational water resource assessments with some form of local cross-validation.本积雪覆盖数据集旨在服务于那些需要获取较高空间分辨率、时效性良好的积雪覆盖存在信息的科学研究应用，其验证基准采用加拿大实地雪道观测数据集。该数据集采用二元积雪/无积雪分类方案，在融雪期其与实地雪道观测数据的偏差率最高可达20%；而在非融雪期，匹配度约为90%。不过此类偏差中至少有一半可归因于随机误差，在对数据集进行空间聚合操作时，这类随机误差会相互抵消。剩余的误差通常与土地覆盖类型相关。若使用者希望利用本积雪覆盖信息驱动其他模型，需充分考虑此类误差特性。本数据集不应在未开展本地化交叉验证的前提下，直接用于业务化水资源评估工作。