Cermak, Jan (2012): Statistics on low cloud occurrence per month along the South-Western African coast at 7:00 and 14:00 UTC, 2004 to 2009 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.755427,

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Supplement to: Cermak, J (2012): Low clouds and fog along the south-western African coast – satellite-based retrieval and spatial patterns. Atmospheric Research, 116, 15-21, https://doi.org/10.1016/j.atmosres.2011.02.012

The spatial and temporal patterns of fog and low clouds along the South-Western African coast are characterized based on an evaluation of Meteosat SEVIRI satellite data. A technique for the detection of fog/low clouds in the region is introduced, and validated using 1 year of CALIOP cloud lidar products, showing reliable performance. The frequency of fog and low cloud in the study area is analyzed by systematic application of the technique to all available Meteosat SEVIRI scenes from 2004 to 2009, for 7:00 UTC and 14:00 UTC. The highest frequencies are encountered in the area around Walvis Bay, with a peak in the summer months. Fog and low clouds clear by 14:00 UTC almost everywhere over land.

Relative and absolute frequencies of fog and low cloud occurrence along the South-Western African coast are provided at 7:00 and 14:00 UTC on a monthly basis, covering the years 2004 to 2009. In addition, information about low cloud persistence over the day is provided. The product is based on a classification of METEOSAT SEVIRI satellite data as described in the manuscript. (Two data sets in NetCDF-format in zip-archive).