1. Climate Studies; Modelling and Environmental Health Research Group; Council for Scientific and Industrial Research; Pretoria; South Africa
2. Laboratoire d'Optique Atmosphérique; Sciences et Technologies; CNRS/INSU; Université Lille 1; Villeneuve d'Ascq Cedex; France
3. School of Chemistry and Physics; University of KwaZulu-Natal; Durban; South Africa
4. South African Weather Service; Pretoria; South Africa
5. UMS 3365 - OSU Réunion; Université de La Réunion; Saint Denis Cedex 09 La Réunion; France