1. Department of Environmental Sciences; University of Virginia; Charlottesville Virginia USA
2. Atmosphere and Energy Research Group; University of the Witwatersrand; Johannesburg South Africa
3. Science Systems and Applications, Inc.; Lanham Maryland USA
4. Earth Sciences Directorate; NASA Goddard Space Flight Center; Greenbelt Maryland USA
5. Laboratory for Atmospheres; NASA Goddard Space Flight Center; Maryland USA
6. Laboratory for Terrestrial Physics; NASA Goddard Space Flight Center; Greenbelt Maryland USA
7. Division of Water, Environment and Forestry Technology; CSIR; Pretoria South Africa