Towards Transparent Air Quality Monitoring in the Ports of the Southern Region

Maritime activities contribute to air pollution in coastal areas and port cities. In Marseille, France's second largest city, the maritime sector is the main contributor to NOx emissions (53%), ahead of road transport (31%) [1]. This sector is poorly regulated, and its emissions vary according to commercial and tourist demands, with no downward trend.

Recently, numerous projects have highlighted the contribution of plumes to local air quality. Within these plumes, observations have shown that ultrafine particle concentrations can exceed 700,000 particles/cm³ and nitrogen oxide concentrations can reach 1,000 µg/m³ instantaneously [2]. They have shown that ship emissions are responsible for the formation of secondary particles, equivalent to their primary emissions [3]. These studies have also enabled us to refine emission factors for particle numbers [2], VOC emissions [4], chemical elements [5], as well as the abatement factors enabled by pollution control systems or alternative fuels, such as LNG [6]. 3D simulations have also made it possible to study plume dispersion in the near field at very high resolution [7]. They have highlighted that ship plumes significantly degrade air quality over short periods, on the order of a few minutes, in impact zones ranging from 10m to 100m.

These results have prompted public authorities and stakeholders to implement mitigation actions. To monitor their performance, port stakeholders have signed a unique and innovative agreement with AtmoSud, an independent air quality monitoring observatory. This agreement paves the way for sharing technical data from ships and activities in real time at ports. It enables transparent monitoring of the effectiveness of actions implemented to reduce the environmental impact of ships. This sharing has made it possible to significantly improve the quality of emission inventories and to highlight the reduction gains of the actions undertaken.

The sharing of these data is accompanied by the deployment of a measurement system in the region’s main ports, comprising  reference cabins for ultrafine particles, PM2.5, Black Carbon, SO₂, NOx, and O₃, as well as micro-sensors placed in and around the port. This system allows for the integration of innovative monitoring devices such as hyperspectral cameras to study plume dispersion in the near field [8] or measurement campaigns to enhance knowledge.

AtmoSud gratefully acknowledges the important ongoing collaborations with shipping companies such as Corsica Linea and Corsica Ferries, as well as with research laboratories such as LCE, IMT, INERIS, IGE, IFPEN, WaltR, and the financial support from European Union, ADEME and Région Sud.

[1] AtmoSud, Annual emissions inventory, version 11.1

[2] SCIPPER, Atmospherically sampled ship plume characterization, 2022.

[3] SCIPPER booklet, 2024.

[4] Dufresne et al., (2021). High quality monitoring dataset needed for improving VOC emission knowledge in a Mediterranean port city. 10.5194/egusphere-egu21-15080.

[5] Le Berre et al., (2024). Measurement report: In-depth characterization of ship emissions during operations in a Mediterranean port. 10.5194/egusphere-2024-2903.

[6] SCIPPER, New set of emission factors and activity information, 2021.

[7] AerNostrum, Rapport sur les résultats des simulations du modèle, 2023. French.

[8] ARCADIA Project, in progress. WaltR, AtmoSud. French.