My project consists of studying the air-sea CO2 exchanges in costal environments at different time scales: diurnal to interannual. We rely on high-frequency data from automated buoys of opportunity located in the south western English Channel and French Mediterranean continental shelf. I apply statistical tools to analyse these signals and understand small scale phenomena. For the long term study, I rely on 10 years of data collected by the Roscoff and Villefranche-sur-mer stations (SOMLIT) to assess long-term evolution CO2 air-sea fluxes. The aim of this study is to improve forecast models of CO2 air-sea exchanges by including the high variability of coastal environments.

Research experiences

2017 - 2nd yr Master internship – Marine Chemistry team – Station biologique de Roscoff/CNRS, Roscoff, France (Supervisor : Y. Bozec)
High-frequency study of processes controlling air-sea CO2 emissions in the Western English Channel.

2016 - 2nd yr Master internship – LEMAR, IUEM, Plouzané, France (Supervisors : R. Riso, M. Waeles, B. Pernet-Coudrier, P. Nonotte)
Elementary and isotopic analysis of river water under agricultural areas.

2015 - 1st yr Master internship – Marine chemistry laboratory, IRD, Plouzané, France (Supervisor : F. Baurand)
Development of an analytical chain of dissolved oxygen by the Winkler method.

2012 - 2nd year DUT internship – Metrology and chemistry laboratory, SHOM, Brest, France (Supervisor : M. Le Menn)
Calibration and optimization of a densimeter.


Since 2017 - PhD Chemical oceanography – Marine Chemistry Team, Station biologique de Roscoff/ Sorbonne University.

2016/2017 - MSc Optimisation of experimental protocols, UBO, Brest, France.

2014/2016 - MSc Marine Chemistry, IUEM, Plouzané, France.

2013/2014 - BSc Chemistry, UBO, France.

2010/2012 - Technology degree Physical measurements, IUT de Lannion, France.



Gac J.-P., Marrec P., Cariou T., Guillerm C., Macé É., Vernet M. & Bozec Y. 2020. Cardinal Buoys: An Opportunity for the Study of Air-Sea CO2 Fluxes in Coastal Ecosystems. Frontiers in Marine Science, 7.  10.3389/fmars.2020.00712

Gac J.-P., Cariou T., Macé É., Vernet M. & Bozec Y. 2020. Statistical Analysis of High-Frequency pCO2 Data Acquired with the ASTAN buoy (South-Western English Channel, Off Roscoff). In: Evolution of Marine Coastal Ecosystems under the Pressure of Global Changes (Ceccaldi H-J, Hénocque Y, Komatsu T, Prouzet P, Sautour B, Yoshida J eds). Springer International Publishing. chapter 5, pp. 67-82. 10.1007/978-3-030-43484-7_5

Kitidis V.,  Shutler J. D., Ashton I., Warren M., Brown I., Findlay H., Hartman S. E., Sanders R., Humphreys M., Kivimäe C., Greenwood N., Hull T., Pearce D., McGrath T., Stewart B. M., Walsham P., McGovern E., Bozec Y., Gac J.-P. , van Heuven S. M.A.C., Hoppema M., Schuster U., Johannessen T., Omar A., Lauvset S. K., Skjelvan I., Olsen A., Steinhoff T., Körtzinger A., Becker M., Lefevre N., Diverrès D., Gkritzalis T., Cattrijsse A., Petersen W., Voynova Y., Chapron B., Grouazel A., Land P. E., Sharples J., Nightingale P. D.. 2019.  Winter weather controls net influx of atmospheric CO2 on the north-west European shelf. Scientific Reports 9, 20153.