CLARA-A1: A cloud, albedo, and radiation dataset from 28 yr of global AVHRR data
A new satellite-derived climate dataset – denoted CLARA-A1 (" The CM SAF cLoud, Albedo and RAdiation dataset from AVHRR data ") – is described. The dataset cov-ers the 28 yr period from 1982 until 2009 and consists of cloud, surface albedo, and radiation budget products de-rived from the AVHRR (Advanced Very High Resolution Ra-diometer) sensor carried by polar-orbiting operational mete-orological satellites. Its content, anticipated accuracies, limi-tations, and potential applications are described. The dataset is produced by the EUMETSAT Climate Monitoring Satel-lite Application Facility (CM SAF) project. The dataset has its strengths in the long duration, its foun-dation upon a homogenized AVHRR radiance data record, and in some unique features, e.g. the availability of 28 yr of summer surface albedo and cloudiness parameters over the polar regions. Quality characteristics are also well investi-gated and particularly useful results can be found over the tropics, mid to high latitudes and over nearly all oceanic ar-eas. Being the first CM SAF dataset of its kind, an intensive evaluation of the quality of the datasets was performed and major findings with regard to merits and shortcomings of the datasets are reported. However, the CM SAF's long-term commitment to perform two additional reprocessing events within the time frame 2013–2018 will allow proper handling of limitations as well as upgrading the dataset with new fea-tures (e.g. uncertainty estimates) and extension of the tempo-ral coverage.