Free Tropospheric Aerosols Over South Africa

¹ Finnish Meteorological Institute, FI-70211, Kuopio, Finland
² Department of Applied Physics, University of Eastern Finland, FI-70211 Kuopio, Finland
³ Finnish Meteorological Institute, FI-00101, Helsinki, Finland
⁴ Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
⁵ Leibniz Institute for Tropospheric Research, Permoserstrasse 15, D-04318, Leipzig, Germany
⁶ Department of Environmental Sciences, University of Eastern Finland, FI-70211 Kuopio, Finland

^* Email: eleni.giannakaki@fmi.fi

Published online: 7 June 2016

Abstract

Raman lidar data of one year was been analyzed to obtain information relating aerosol layers in the free troposphere over South Africa, Elandsfontein. In total, 375 layers were observed above the boundary layer during the period 30th January 2010 – 31^st January 2011. The seasonal behavior of aerosol layer geometrical characteristics as well as intensive and extensive optical properties were studied. In general, layers were observed at higher altitudes during spring (2520 ± 970 m) while the geometrical layer depth did not show any significant seasonal dependence. The variations of most of the intensive and extensive optical properties analyzed were high during all seasons. Layers were observed at mean altitude of 2100 m ± 1000 m with lidar ratio at 355 nm of 67 ± 25 and extinction-related Ångström exponent between 355 and 532 nm of 1.9 ± 0.8.