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Melilotus Thyssen

Mélilotus Thyssen CNRS Researcher, Marine microbial Ecologist and Biogeochemist
9
Documents

Présentation

I am a marine microbiologist and biogeochemist, dealing with the multiparametric complexity of the ocean and the microorganisms floating inside.I am looking at the very small scales related to phytoplankton organisms, as far as we can. Meaning I study all together their functional diversity (regarding their role in biogeochemical processes), their structural diversity (how the functional groups or species are making a community), and most of all, the dynamical behavior of each entity within the community (hourly to daily physiological changes and abundances variations), surrounded by water in motion. The use of high resolution automated sensors capable of precise single cell observation that can give insight to phytoplankton functional and structural heterogeneity within spatial and temporal variability is part of my job. I use automated flow cytometry in combination with several sensors deciphering the surrounding chemical and physical conditions. I am singularly looking into the very fast reactivity of the smallest phytoplankton size classes (pico-nanophytoplankton) after drastic environmental changes (as an example, after the upper layer mixing linked to strong winds), especially in the oligotrophic regions where low productivity is expected. I also collect basin scale high resolution phytoplankton distribution to understand large scale seasonal changes in hydrological properties affecting phytoplankton community structure and spatial heterogeneity. From the tiny single cell observation at high resolution (km scale/hourly scale) to the large scale observation increases datasets quality and our potential of undertanding. Combination with remote sensing (PHYSAT for example) and modelling will increase the sensitivity of extrapolation and sharpen our understanding.

Domaines de recherche


Compétences

Flow cytometry, sea water flowthrough, primary production, big data analysis,

Publications

roxane-tzortzis
Image document

New insights for direct in situ measurement of oceanic vertical velocities in fine-scale studies.

Caroline Comby , Stéphanie Barrillon , Jean-Luc Fuda , Andrea M. Doglioli , Roxane Tzortzis
EGU General Assembly 2021, Apr 2021, online, Austria. ⟨10.5194/egusphere-egu21-4632⟩
Communication dans un congrès hal-03377993v1
Image document

Study of fine-scale dynamics and their coupling with biogeochemistry - FUMSECK cruise

S. Barrillon , Caroline Comby , Jean-Luc Fuda , Anne Petrenko , Melilotus Thyssen
EGU General Assembly 2021, Apr 2021, Vienne, Austria. ⟨10.5194/egusphere-egu21-7199⟩
Communication dans un congrès hal-03375185v1
Image document

Recent progress in the study of fine-scale physical-biological coupling in the Mediterranean Sea.

Roxane Tzortzis , Andrea M. Doglioli , Stéphanie Barrillon , A. A Petrenko , Francesco d'Ovidio
EGU General Assembly 2021, Apr 2021, Vienne, Austria. ⟨10.5194/egusphere-egu21-7133⟩
Communication dans un congrès hal-03375405v1

A new approch for measuring oceanic vertical velocities

Jean-Luc Fuda , Stéphanie Barrillon , Andrea M. Doglioli , Anne Petrenko , Gérald Grégori
EGU General Assembly 2021, Apr 2021, On Line, Austria
Communication dans un congrès hal-03396001v1
Image document

Combining remote sensing and in situ observations to study the physical-biological coupling at fine scale: recent Mediterranean campaigns and outlook

Andrea M. Doglioli , Gérald Grégori , Francesco d'Ovidio , Anne Petrenko , Stéphanie Barrillon
EGU General Assembly 2020, EGU, May 2020, On line, France. ⟨10.5194/egusphere-egu2020-7356⟩
Communication dans un congrès hal-02962520v1
Image document

A Lagrangian strategy for in situ sampling the physical-biological coupling at fine scale : the PROTEVSMED-SWOT 2018 cruise

Roxane Tzortzis , Andrea M. Doglioli , Stéphanie Barrillon , Anne Petrenko , Francesco d'Ovidio
EGU General Assembly 2020, May 2020, On-line, France. ⟨10.5194/egusphere-egu2020-7357⟩
Communication dans un congrès hal-02968298v1