Assessing the fitness of satellite albedo products for monitoring snow albedo trends

Accurate monitoring of albedo trends over snow is essential to evaluate the consequences global cover retreat on Earth’s energy budget. Satellite observations provide best way monitor these globally, but their uncertainty increases snow. Besides, different products sometimes show diverging trends. A better assessment fitness satellite for needed. We analyze consistency black-sky estimates from long-term snow: AVHRR-based (CLARA-A2.1, GLASS-v4.2), MODIS-based (MCD43C3-v6.1/v6, MISR-based (MIL3MLSN-v4) and multi-sensor (C3S-v1/v2). use MCD43C3-6.1 as reference based a previous comparison against in-situ measurements. CLARA-A2.1 one most consistent with MCD43C3, has low coverage in high latitudes an artificial decrease since 2015. The study shows limitations MIL3MLSN, GLASS, C3S MIL3MLSN too-low GLASS-AVHRR overestimates regions seasonal due delayed snowmelt underestimates it permanently snow-covered regions. GLASS-MODIS more MCD43C3 at mid-latitudes, also permanent increase missing values after 2011. Both GLASS datasets are temporally inconsistent other products. Despite improvements v1 v2, C3S-v2 largest negative bias discontinuities transitions between sensors. evidences difficulties AVHRR stable polar regions, particularly before 2000.