A European Time Series of Daily Snow Cover From Avhrr Data Over 36 Years: Results of the Timeline Project

Abstract

The TIMELINE project is dedicated to generating comprehensive and consistent long-term time series using NOAA and METOP AVHRR data for Europe and North Africa, utilizing the extensive DLR-DFD historical data archive. Its primary objective is to address socially significant inquiries regarding climate change and identify potential trends. To achieve this, the project has developed a multitude of processors that produce essential data products pertaining to radiation, land surface, atmosphere, and cryosphere. Specifically focusing on the cryosphere, the daily estimation of the snow-covered area from AVHRR data between 1982 and 2018 in TIME-LINE provides an unprecedented 36-year period of observation, almost doubling the duration of available MODIS snow product records in the region. This paper presents the snow cover processor, along with the initial outcomes of the time series analysis, shedding light on important insights gained from the data.