1. Earth Observation Science Group, Department of Physics and Astronomy; University of Leicester; Leicester UK
2. National Centre for Earth Observation; University of Leicester; Leicester UK
3. Instituto de Pesquisas Energéticas e Nucleares-Comissao Nacional de Energia Nuclear-Atmospheric Chemistry Laboratory; Cidade Universitária; São José dos Campos Brazil
4. Greenhouse Gases Laboratory; Instituto Nacional de Pesquisas Espaciais; São Paulo Brazil
5. School of Geography; University of Leeds; Leeds UK
6. School of GeoSciences; University of Edinburgh; Edinburgh UK
7. NCEO; University of Edinburgh; Edinburgh UK
8. School of Earth and Environment; University of Leeds; Leeds UK
9. NCEO; University of Leeds; Leeds UK
10. Global Monitoring Division, Earth System Research Laboratory; National Oceanic and Atmospheric Administration; Boulder Colorado USA
11. Cooperative Institute for Research in Environmental Sciences (CIRES); University of Colorado Boulder; Boulder Colorado USA
12. Institute of Environmental Physics; University of Bremen; Bremen Germany