Biogeochemical blindspots along the lower Amazon River continuum: from land to the atmosphere and ocean

• Grant number: 18/18491-4
• Support type: Research Projects - SPEC Program
• Duration: May 01, 2019 - April 30, 2023
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal researcher: Jeffrey Edward Richey
• Grantee: Jeffrey Edward Richey
• Home Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Pesquisadores principais: Maria Victoria Ramos Ballester
• Assoc. researchers: Alan Cavalcanti da Cunha ; André Oliveira Sawakuchi ; Daimio Chaves Brito ; Henrique Oliveira Sawakuchi ; Maria de Lourdes Cavalcanti Barros ; Milton Kampel ; Nicholas Ward ; Paulo Cesar Colonna Rosman ; Richard G Keil ; Vania Neu
• Associated scholarship(s): 20/15514-3 - Understanding the Lower Amazon River, BP.TT; 20/08666-1 - Application of coupled SisBaHiA® hydrodynamic/biogeochemistry model for computing net ecosystem exchange across the Lower Amazon River-to-Ocean Continuum, BP.PD; 20/08148-0 - Spatiotemporal variability of pCO2 of the Amazon River by ocean color remote sensing: from river to the plume, BP.PD

Abstract

The research objective is to examine, at different scales, the processes that govern the advection and reaction of carbon in the lowest reach of the Amazon River and along the near-shore coastline of the Western Tropical Atlantic Ocean. The mainstem of the river is a large supplier of carbon dioxide (CO2) to the atmosphere, most of which is sourced as organic carbon from the surrounding landscape and subsequently remineralized in river. The component of the river system that is least well understood is the lower tidal reach, which consists of two main channels across from Macapá down 150 km to the ocean. While tidal forcing does not result in salt intrusion, riverine flow in this reach can be reversed, and complex interactions occur between the river channels and the fringe areas, making the study of this component of the world's largest river a significant logistical challenge. Through an ambitious field study, the project aims to understand the large-scale drivers (e.g. hydrodynamics, areal extent, metabolism) that create the spatial and temporal variability in carbon remineralization and CO2 fluxes in the lower river. This will be addressed using a combination of fieldwork, remote sensing and modeling. In addition, the types of organic matter that are degraded, the microorganisms and consortia that remineralize, and the metabolic pathways (aerobic, anaerobic) that lead to the large production of CO2 will be evaluated using a combination of organic geochemical and molecular biological (proteomic) tools. The proposed work will provide in situ observations in a previously unstudied region of high global importance, experimentation focused on unraveling the influence of physical factors (e.g. tides, current velocity, and mixing) on biological processes, spatial and temporal variability of CO2 fluxes by remote sensing, and modeling tools capable of predicting the sensitivity of Net Ecosystem Exchange (NEE). (AU)

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VALERIO, ALINE DE M.; KAMPEL, MILTON; VANTREPOTTE, VINCENT; WARD, NICHOLAS D.; RICHEY, JEFFREY E. Optical Classification of Lower Amazon Waters Based on In Situ Data and Sentinel-3 Ocean and Land Color Instrument Imagery. REMOTE SENSING, v. 13, n. 16 AUG 2021. Web of Science Citations: 0.

BERTASSOLI, JR., DAILSON J.; SAWAKUCHI, HENRIQUE O.; DE ARAUJO, KLEITON R.; DE CAMARGO, MARCELO G. P.; ALEM, VICTOR A. T.; PEREIRA, TATIANA S.; KRUSCHE, V, ALEX; BASTVIKEN, DAVID; RICHEY, JEFFREY E.; SAWAKUCHI, ANDRE O. How green can Amazon hydropower be? Net carbon emission from the largest hydropower plant in Amazonia. SCIENCE ADVANCES, v. 7, n. 26 JUN 2021. Web of Science Citations: 0.

SAWAKUCHI, HENRIQUE O.; BASTVIKEN, DAVID; ENRICH-PRAST, ALEX; WARD, NICHOLAS D.; CAMARGO, PLINIO B.; RICHEY, JEFFREY E. Low Diffusive Methane Emissions From the Main Channel of a Large Amazonian Run-of-the-River Reservoir Attributed to High Methane Oxidation. FRONTIERS IN ENVIRONMENTAL SCIENCE, v. 9, APR 8 2021. Web of Science Citations: 0.

VALERIO, ALINE M.; KAMPEL, MILTON; WARD, NICHOLAS D.; SAWAKUCHI, HENRIQUE O.; CUNHA, ALAN C.; RICHEY, JEFFREY E. CO2 partial pressure and fluxes in the Amazon River plume using in situ and remote sensing data. CONTINENTAL SHELF RESEARCH, v. 215, FEB 15 2021. Web of Science Citations: 0.