1. Department of Geological and Mining Engineering and Sciences; Michigan Technological University; Houghton Michigan USA
2. Department of Mineral Sciences, National Museum of Natural History; Smithsonian Institution; Washington District of Columbia USA
3. Department of Atmospheric and Oceanic Science; University of Maryland College Park; College Park Maryland USA
4. Atmosphere and Climate Department; Norwegian Institute for Air Research; Kjeller Norway
5. Armospheric Chemistry and Dynamics Laboratory, Code 614; NASA Goddard Space Flight Center; Greenbelt Maryland USA