The NIEER AVHRR snow cover extent product over China – a long-term daily snow record for regional climate research

• Published in: Earth system science data 2021-10, Vol.13 (10), p.4711-4726
• Main Authors: Hao, Xiaohua, Huang, Guanghui, Che, Tao, Ji, Wenzheng, Sun, Xingliang, Zhao, Qin, Zhao, Hongyu, Wang, Jian, Li, Hongyi, Yang, Qian
• Format: Article
• Language: English
• Subjects: Accuracy; Advanced Very High Resolution Radiometer; Algorithms; Climate change; Cloud detection; Daily precipitation; Datasets; Depth measurement; Landsat; Landsat satellites; Meteorological satellites; Quality control; Radiometers; Regional climates; Regions; Remote sensing; Resolution; Satellite imagery; Sensors; Snow; Snow cover; Spatial discrimination; Spatial resolution; Temperature; Temporal resolution; Time series
• ISSN: 1866-3516; 1866-3508; 1866-3516
• DOI: 10.5194/essd-13-4711-2021

A long-term Advanced Very High Resolution Radiometer (AVHRR) snow cover extent (SCE) product from 1981 until 2019 over China has been generated by the snow research team in the Northwest Institute of Eco-Environment and Resources (NIEER), Chinese Academy of Sciences. The NIEER AVHRR SCE product has a spatial resolution of 5 km and a daily temporal resolution, and it is a completely gap-free product, which is produced through a series of processes such as the quality control, cloud detection, snow discrimination, and gap-filling (GF). A comprehensive validation with reference to ground snow-depth measurements during snow seasons in China revealed the overall accuracy is 87.4 %, the producer's accuracy was 81.0 %, the user's accuracy was 81.3 %, and the Cohen's kappa (CK) value was 0.717. Another validation with reference to higher-resolution snow maps derived from Landsat-5 Thematic Mapper (TM) images demonstrates an overall accuracy of 87.3 %, a producer's accuracy of 86.7 %, a user's accuracy of 95.7 %, and a Cohen's kappa value of 0.695. These accuracies were significantly higher than those of currently existing AVHRR products. For example, compared with the well-known JASMES AVHRR product, the overall accuracy increased approximately 15 %, the omission error dropped from 60.8 % to 19.7 %, the commission error dropped from 31.9 % to 21.3 %, and the CK value increased by more than 114 %. The new AVHRR product is already available at https://doi.org/10.11888/Snow.tpdc.271381 (Hao et al., 2021).