高亚洲逐日积雪覆盖率数据集（2002-2016）

由于青藏高原地区季节性积雪具有赋存时间短、雪层较薄的特点，在对水循环等问题的理解中，迫切需要日时间尺度的积雪覆盖率动态监测数据。本数据集基于MODIS Snow Cover Daily L3 Global 500 m Grid数据，包括MODIS/Terra上午星数据（MOD10A1）和MODIS/Aqua下午星数据（MYD10A1）的归一化积雪指数NDSI数据产品，数据格式为hdf，投影方式为正弦曲线地图投影，结合90m的SRTM地形数据和多种云覆盖下积雪覆盖率估算算法的优势，实现云覆盖条件下的积雪覆盖率再估算，满足高亚洲地区逐日少云（＜ 10％）数据产品的生产要求，构建了 2002 - 2016 年高亚洲地区 MODIS 逐日积雪覆盖率数据集。选取无云条件下的二值积雪产品作为参考，通过云量分布和积雪总面积的时空对比，表明该产品的时空特征和二值产品具有较好的一致性。以 2013 年冬季为例，当积雪覆盖率大于 50％时，其相关性可达 0.8628。本数据集可为高亚洲地区的积雪动态监测、气候环境、水文和能量平衡、灾害评估等研究提供逐日积雪覆盖率数据。

Given the short residence time and thin snow cover of seasonal snow cover in the Tibetan Plateau, dynamically monitored daily-scale snow cover fraction data are urgently needed for understanding issues such as the water cycle. This dataset is developed based on the MODIS Snow Cover Daily L3 Global 500 m Grid data, including the Normalized Difference Snow Index (NDSI) products from MODIS/Terra morning satellite (MOD10A1) and MODIS/Aqua afternoon satellite (MYD10A1). The data are stored in HDF format with Sinusoidal map projection. By leveraging the advantages of 90 m SRTM topography data and multiple snow cover fraction estimation algorithms under cloud cover, we achieved the re-estimation of snow cover fraction under cloud-covered conditions, meeting the production requirements of daily low-cloud (<10%) data products for High Mountain Asia (HMA). Consequently, a daily MODIS snow cover fraction dataset for High Mountain Asia spanning 2002 to 2016 was constructed. We selected the cloud-free binary snow cover product as the reference. Through spatiotemporal comparison of cloud cover distribution and total snow cover area, it is verified that the spatiotemporal characteristics of this dataset are highly consistent with those of the binary snow cover product. Taking the winter of 2013 as an example, the correlation coefficient reaches 0.8628 when the snow cover fraction is greater than 50%. This dataset can provide daily snow cover fraction data for studies on dynamic snow cover monitoring, climatic environment, hydrological and energy balance, disaster assessment and other relevant research in High Mountain Asia.

搜集汇总

背景与挑战

背景概述

该数据集为2002-2016年高亚洲地区的逐日积雪覆盖率数据，基于MODIS Snow Cover Daily L3 Global 500 m Grid数据，结合SRTM地形数据和云覆盖估算算法，满足少云数据产品要求，适用于积雪动态监测、气候环境、水文和能量平衡、灾害评估等研究。