CLARA-A3: The third edition of the AVHRR-based CM SAF climate data record on clouds, radiation and surface albedo covering the period 1979 to 2023

This paper presents the third edition of The Satellite Application Facility on Climate Monitoring’s
(CM SAF) cloud, albedo, and surface radiation dataset from advanced very-high-resolution radiometer (AVHRR)
data, CLARA-A3. The content of earlier CLARA editions, namely cloud, surface albedo, and surface radiation
products, has been extended with two additional surface albedo products (blue- and white-sky albedo), three
additional surface radiation products (net shortwave and longwave radiation, and surface radiation budget), and
two top of atmosphere radiation budget products (reflected solar flux and outgoing longwave radiation). The
record length is extended to 42 years (1979–2020) by also incorporating results from the first version of the
advanced very high resolution radiometer imager (AVHRR/1). A continuous extension of the climate data record
(CDR) has also been implemented by processing an interim climate data record (ICDR) based on the same
set of algorithms but with slightly changed ancillary input data. All products are briefly described together
with validation results and intercomparisons with currently existing similar CDRs. The extension of the product
portfolio and the temporal coverage of the data record, together with product improvements, is expected to
enlarge the potential of using CLARA-A3 for climate change studies and, in particular, studies of potential
feedback effects between clouds, surface albedo, and radiation.
The CLARA-A3 data record is hosted by the European Organisation for the Exploitation
of Meteorological Satellites (EUMETSAT) CM SAF and is freely available at
https://doi.org/10.5676/EUM_SAF_CM/CLARA_AVHRR/V003 (Karlsson et al., 2023b).