Amazon Research Objectives:

   The River Systems Research Group has a long history of working on the biogeochemistry of the Amazon. Following a pilot "cruise" of the UNOLS vessel Alpha Helix, in 1977, the NSF, NASA, and Brazilian- supported project CAMREX (Carbon in the AMazon River Experiment) began, in 1982. Work continued through NSF, FAPESP, and the NASA ABLE (mid 90's), EOS, and LBA (2000s) programs. As part of the ROCA (River-Ocean Continuum of the Amazon) project, we began to work on the lower Amazon, from Obidos (the last routine measuring station, 900 km inland), to the ocean). THe ROCA proejct led to the development of the current TROCAS progam. 

The overall perspective in CAMREX has been that the Amazon is a test case for developing extendable models of how hydrologic and biogeochemical cycles are coupled at regional to continental scales in the humid tropics. Our studies serve the dual purposes of gaining a broad mechanistic understanding and of establishing data baselines needed to assess anthropogenic perturbations to these globally critical and ecologically complex systems. As documented in over 150 publications, the CAMREX dataset represents a time series unique in its length and detail for very large river systems. The focus over the last several years has been to examine the sequence of processes involved in the dynamics of carbon metabolism, resulting in high outgassing. Richey et al. (2002) showed that the outgassing from the aquatic systems of the Amazon are roughly equivalent to the carbon sequestered on land, and over 10x the carbon exported to the sea. Papers have addressed modeling and system integration (Richey et al. 2004; Richey 2004, 2005), biogeochemistry within geospatial frameworks (Ballester et al. 2003, 2005; Bernardes et al. 2004; Mayorga et al. 2005a, Logsdon et al. 2005; Krusche et al. 2005), hydrologic models (Victoria et al. 2007), gas exchange (Rasera et al. 2008; Alin et al.2011), basin scale tracers of sorption and metabolic properties (Martinelli et al. 2003; Mayorga et al. 2005b; Aufdenkampe et al. 2007; Remington et al. 2007; Souza et al. 2008; Ellis et al. in press), and chemical properties (Dickens et al. 2007, Tumang et al. 2007). Richey et al. (2010, 2011) summarized the current understanding of carbon in Amazon rivers. 

     A signature of CAMREX is that is has been a joint, collaborative effort of the UW and Brazilian institutions, in particular CENA (Centro de Energia Nuclear na Agricultura, Piracicaba SP) and INPA (Instituto Nacional de Pesquisas da Amazonia, Manaus).  As part of LBA, we established the education and sampling network the Rede Beija Rio (RBR), supported subsequently by the Brazilian government (FAPESP, CNPq). The RBR serves the dual purpose of enabling higher frequency (and less expensive) sampling than possible by sending teams from São Paulo or Seattle, and especially serves as our primary vehicle for training and capacity building. The sites are organized as transects, from the Amazon mainstem and major tributary mouths (the initial CAMREX scheme), to primary tributaries, then sub-tributaries, and ultimately streams The RBR is made up of nodes distributed across the Amazon, where each node is occupied by a researcher or a team of researchers from that site-typically a professor, graduate and/or undergraduate students from local institutions, working from a coordinated sampling plan. Over 40 Brazilian students have participated in the project since its beginning, earning Masters and PhDs. Most of these students have been from the Amazon, a region markedly under-represented in technical training in the country.