The first-order difference: A potential methodology to evaluate fractional snow cover time series

Reconstructed fractional snow covered area (FSCA) with temporal continuity generally lacks independent evaluations due to poor ground truth data under cloudy weather. As FSCA time series might vary sensitively and monotonically with grid-scale snow depth (SD) under particular conditions, we are going to propose the first-order difference methodology to utilize this characteristic to alleviate the evaluation problem partially.