Post-doctoral fellow on "The impact of phytoplankton on the composition of marine aerosols and CCN properties."

We now know that a significant proportion of the chemical composition of marine aerosols comes from marine phytoplankton. This material may be of primary origin, through the emission of organic matter (sugars, lipids, bacteria, planktonic debris, etc.) during wave breaking. It can also come from the emission of trace gases (DMS, MeSH, isoprene, etc.) which, once in the atmosphere, oxidize into semi-volatile compounds and contribute to the formation of new particles or the enlargement of existing marine aerosols. Phytoplankton thus directly influences the properties of aerosols and modifies the life cycle of clouds (indirect effect). Taking phytoplankton emissions into account is therefore a challenge for improving numerical weather and climate prediction models. Numerical modeling of these processes can only be done by understanding the interactions between the atmosphere, sea conditions, and marine biology.

The VACOA campaign (MAP-IO program, www.mapio.re), conducted in the Southern Ocean aboard the Marion Dufresne between January and March 2026, will study all of these processes simultaneously through a unique combination of physico-chemical measurements of gases, aerosols, phytoplankton, and meteorology.

The aim is to model these primary and secondary marine aerosol formation processes using a coupled ocean-wave-atmosphere approach: MesoNH, Croco/PISCES and WAVEWATCH III models. This type of numerical representation is unique in the world and will enable us to overcome existing barriers concerning the complex interactions between dynamics and physical chemistry that occur at the interface between the ocean and the atmosphere.

We invite young researchers interested in the subject and by numerical modeling to contact us to submit an MSCA application.

At the aerology laboratory in Toulouse (France), the fellow will be working alongside specialists in aerosols, ocean-atmosphere interactions, and numerical coupling. The fellow will be included into the VACOA consortium, benefitting from full access to the cruise's database. Further collaborations with local experts in Toulouse from CNRM, LEGOS, and Mercator Ocean International are foreseen. Access to the French metoffice HPC will be granted.

Contacts: pierre.tulet@cnrs.fr, sophia.brumer@cnrs.fr, joris.pianezze@cnrs.fr

Web sites:

LAERO: https://www.aero.obs-mip.fr/en/laboratoire-daerologie/

IN MAP-IO: www.mapio.re

MesoNH: http://mesonh.aero.obs-mip.fr

Croco: https://www.croco-ocean.org

PISCES: https://www.pisces-community.org

WAVEWATCH III: https://polar.ncep.noaa.gov/waves/wavewatch/

Mercator Ocean International: https://www.mercator-ocean.eu/

Bibliography related to the program:

Tulet, et al., P, Earth Syst. Sci. Data, 16, 3821–3849, https://doi.org/10.5194/essd-16-3821-2024, 2024.

Lac, et al. , Geosci. Model Dev., 11, 1929–1969, https://doi.org/10.5194/gmd-11-1929-2018, 2018.

Hoarau, et al., 2018 Journal of Geophysical Research: Atmospheres, 123, 8813–8831. https://doi.org/10.1029/2017JD028125

Pianezze, et al., Journal of Geophysical Research: Atmospheres, 124, 11389– 11405, 2019, https://doi.org/10.1029/2019JD031122

Tulet, P., et al, 2005. J. Geophys. Res. Vol. 110 , doi:10.1029/2004.

Brumer, S. E.,et al. 2017. J. Phys. Oceanogr., 47, 2211–2235, https://doi.org/10.1175/JPO-D-17-0005.1.

Brumer, S. E., et al. 2017 Geophysical Research Letters, 44, 9865–9875. https://doi.org/10.1002/2017GL074979