Evaluating the performance of the EUMETSAT H SAF H35 fractional snow-covered area product over the Tibetan Plateau

Background and aims This study evaluates the performance of the H35 fractional snow-covered area (fSCA) product over the Tibetan Plateau (TP) from May 2019 to December 2021. The H35 product, derived from AVHRR satellite data, provides daily fSCA estimates at a resolution of 0.01°. The aim of this work is to assess the accuracy and reliability of this product in capturing snow cover dynamics over a significant period. Methods Validation of the H35 product uses a high-resolution, cloud-free snow cover dataset derived from long-term MODIS data, ensuring temporal consistency and high accuracy. Statistical metrics, including probability of detection (POD), false alarm ratio (FAR), and accuracy (ACC), were employed to assess the product's performance. Results The results reveal seasonal variations in performance, with POD values reaching a peak of 0.91 during the winter months. The FAR shows an inverse trend, while the overall ACC values remain consistently high, indicating reliable performance across the study period. Conclusions This study contributes to the understanding of snow cover dynamics over the TP and highlights the significance of validating satellite-derived products for hydrological studies. The consistently high accuracy of the H35 product underscores its potential for use in monitoring snow cover in the region.