Proceedings of the 11th International Carbon Dioxide Conference

The climate is changing mainly due to anthropogenic actions that contribute to CO₂ emissions, such as the use of fossil fuels and deforestation. In this context, the ocean has a key role due to its ability to take up and store carbon longer than land. However, there are still huge data gaps about ocean CO₂ around the world and the Brazilian coast is one of these regions. One well-established solution to increase the coverage of CO₂ observations adopted from the Global North is to install autonomous pCO₂ sensors in cargo ships to perform continuous measurements along their routes, called Ship-Of-Opportunity (SOOP). Therefore, the first SOOP line in the Brazilian coast was designed in the collaborative project C-SCOPE (Towards Marine Carbon Observations 2.0: Socializing, COnnecting, Perfecting and Expanding) between GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of the State of Rio de Janeiro, and one goal of which was to install an autonomous system in the cabotage vessel Vicente Pinzon from Aliança, a Maersk company, in November of 2022. The system is composed of a flow-through tank - with submersible sensors for pCO₂, pCH₄, dissolved oxygen, chlorophyll a, turbidity, temperature, and salinity, and a thermometer at the water intake for "in situ" water temperature - connected to the sea chest of the ship and controlled by a water flow sensor. During the first year of the Brazilian SOOP line, we faced several challenges, such as the adaptation of the system to tropical waters, the communication and partnership between the Brazilian public and private sectors, the knowledge exchange, and many others, and hence we still are working on to adapt the SOOP line to the Brazilian coastline and started to fill the CO₂ data gaps.