John M Melack¹, Pedro Maia Barbosa², Joao H. Amaral², Sally MacIntyre³ and Bruce Forsberg⁴, (1)University of California Santa Barbara, Earth Research Institute, Santa Barbara, CA, United States, (2)University of California Santa Barbara, Santa Barbara, United States, (3)Univ California Santa Barbara, Marine Science Institute, Santa Barbara, CA, United States, (4)Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil