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 (pCO₂) made through the Amazon River plume (ARP) during different discharge seasons, from 2010 to 2012. We evaluated the spatiotemporal distribution of pCO₂ using Soil Moisture and Ocean Salinity (SMOS) satellite observations for each hydrologic period in the ARP. Regression models were used to estimate pCO₂ 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 (${\mathit{F}}_{\mathit{co}2}^{\mathit{sea}}$). Intra-annual variability of ${\mathit{F}}_{\mathit{co}2}^{\mathit{sea}}$ 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 ${\mathit{F}}_{\mathit{co}2}^{\mathit{sea}}$. 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.

全球碳预算的估算包括对沿河流到海洋的梯度变化过程的定量理解。但是，这些过程的高时空分辨率观察结果有限。在这里，我们介绍了从2010年到2012年在不同排放季节通过亚马逊河烟流（ARP）进行的CO ₂（pC O ₂）分压的原位测量。我们使用土壤湿度和湿度来评估pC O ₂的时空分布。ARP中每个水文时期的海洋盐度（SMOS）卫星观测。回归模型用于估计pC O ₂在ARP的2010-2014年期间。根据这些分布，我们计算出了羽状水和大气之间的CO ₂海气交换（${\mathit{F}}_{\mathit{合作}2}^{\mathit{海}}$）。的年内变化${\mathit{F}}_{\mathit{合作}2}^{\mathit{海}}$与河口和洋流的排放以及羽流中的顺风有关。研究期间的气候事件对${\mathit{F}}_{\mathit{合作}2}^{\mathit{海}}$。从2011年到2014年，ARP包括更靠近河口的羽流区域，使ARP成为CO ₂的净来源，年净海气通量为8.6±7.1 Tg C y ^-1。