Séminaire d’Erwan Martin

Mardi 27/02/2018 à 14h en salle des séminaires, Erwan MARTIN (ISTEP Paris) présentera ses travaux sur :

Multi O- and S- isotope insight into volcanic sulfate aerosols formation and its impact on the atmosphere. 

The impact of volcanic eruptions on the climate has been studied for the last decades and the role played by sulfate aerosols appear to be major. Indeed, S-bearing volcanic gases are oxidized in the atmosphere into sulfate aerosols, which disturb the radiative balance on earth at more or less global scale. In this presentation we’ll review the use of oxygen and sulfur multi-isotopes approach on volcanic sulfates to discuss their formation and fate in more or less diluted volcanic plumes. The study of volcanic aerosols collected from air sampling and ash deposits at different distances from the volcanic systems (from volcanic vents to the Earth poles) will be discussed; it helps to better constrain the formation of volcanic sulfate aerosols from magmatic, tropospheric to stratospheric conditions. It appears that the accuracy of atmospheric models could be increased by integrating sulfur multi O- and S-isotopic chemistry as the natural volcanic sulfate samples would provide a direct calibration of these models.