Abstract: Various studies explore the relationship between the rising levels of CO2 and CH4 (greenhouse gasses) in the atmosphere and climate changes, and how these increases are connected to human activities. The escalation of these gas species may have implications for the environment. Concerning coastal systems, the rise in greenhouse gas emissions could impact the environment through multiple pathways because the atmosphere and superficial ocean waters also have significant exchanges. The main purpose of this work is to study Greenhouse gasses (GHG), such as CO2 and CH4, on the superficial waters of the coastal region of São Paulo coast. The data were collected in situ on a vessel provided by the Institute of Oceanography of São Paulo University (IOUSP). The campaign was conducted in spring 2022 (10 -11 October) in the south of the coast of São Paulo state, traveling through cities with anthropogenic impacts in principal Santos city, which is located the main port of Sul America. For these in situ measurements a portable gas analyzer Microportable Greenhouse Gas Analyzers (LGR-ICOS TM GLA Series) – was used to detect the CO2 and CH4 spectra through the Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) technique.

Keywords: Methane, Carbon Dioxide, Estuary, GHG, Microportable Gas Analyzers