From Obidos to the Ocean

     TROCAS  (Trocas Líquidas de Carbono do Ecossistema do Baixo Rio Amazonas: Da Terra para o Oceano e Atmosfera; Net Ecosystem Exchange of the Lower Amazon: from Land to the Ocean and Atmosphere) seeks to unravel the sequence of processes and source(s) of terrestrially-derived organic matter (OM) that culminate in the immense CO₂ outgassing to the atmosphere from tropical rivers worldwide, with an immediate focus on the lower Amazon River.  We ask, what are the sources and magnitudes of carbon of terrestrial origin, by fraction, relative to aquatic sources from phytoplankton and macrophytes, in the different sectors of the river system? How much carbon is discharged to the ocean, relative to the atmosphere?

     The Centro de Energia Nuclear na Agricultura (CENA, Piracicaba) and the University of Washington (UW, Seattle) are the lead institutions. Partners in the Amazon include the Universidade Federal do Amapá (UNIFAP, Macapá), the Universidade do Estado do Amapá (UEAP, Macapá), the Universidade Federal do Oeste do Pará (UFOPA, Santarém), and the Universidade Federal Rural da Amazônia (UFRA). Outside of the Amazon, the Instituto Nacional de Pesquisas Espaciais (INPE, Sao José dos Campos) and the Universidade Federal do Rio de Janeiro (COPPE/UFRJ, Rio).

     TROCAS is funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, the science-funding organization of the State of São Paulo), through their  "São Paulo Excellence Chair (SPEC)" thematic program, and the Universidade de Sao Paulo, and by the  NSF Ecosystem Studies program.