CO2 partial pressure and fluxes in the Amazon River plume using in situ and remote sensing data

Author(s)

Valerio, Aline M. ^[1] ; Kampel, Milton ^[1] ; Ward, Nicholas D. ^{[2, 3]} ; Sawakuchi, Henrique O. ^[4] ; Cunha, Alan C. ^[5] ; Richey, Jeffrey E. ^[3]

Affiliation

^[1] Natl Inst Space Res, Ave Astronautas 1758, Sao Jose Dos Campos, SP - Brazil

^[2] Pacif Northwest Natl Lab, Marine Sci Lab, 1529 W Sequim Bay Rd, Sequim, WA - USA

^[3] Univ Washington, Sch Oceanog, 1501 NE Boat St, Seattle, WA 98195 - USA

^[4] Linkoping Univ, Dept Themat Studies Environm Change, SE-58183 Linkoping - Sweden

^[5] Univ Fed Amapa, Dept Exact & Technol Sci, Rod Juscelino Kubitschek, Km 02, Macapa, AP - Brazil

• Document type: Journal article
• Source: CONTINENTAL SHELF RESEARCH; v. 215, FEB 15 2021.
• Web of Science Citations: 0

Abstract

Estimations of the global carbon budget include a quantitative understanding of the evolving processes that occur along river-to-ocean gradients. However, high spatiotemporal resolution observations of these processes are limited. Here we present in situ measurements of the partial pressure of CO2 (pCO(2)) made through the Amazon River plume (ARP) during different discharge seasons, from 2010 to 2012. We evaluated the spatiotemporal distribution of pCO(2) using Soil Moisture and Ocean Salinity (SMOS) satellite observations for each hydrologic period in the ARP. Regression models were used to estimate pCO(2) at the ARP for the period of 2010-2014. From these distributions we calculated sea-air gas exchange of CO2 between the plume waters and the atmosphere (F-co2(sea)). Intra-annual variability of Fseaco(2) was related to discharge at the river mouth and ocean currents as well as trade winds in the plume. Climatic events during the study period had a significant impact on the Fsea co(2). Including the plume area closer to the river mouth makes the ARP a net source of CO2 with an annual net sea-air flux of 8.6 +/- 7.1 Tg C y(-1) from 2011 to 2014. (AU)

• FAPESP's process: 18/18491-4 - Biogeochemical blindspots along the lower Amazon River continuum: from land to the atmosphere and ocean
• Grantee: Jeffrey Edward Richey
• Support Opportunities: Research Projects - SPEC Program