Description du projet
Modéliser les dépôts d’ozone sur l’une des plus grandes interfaces au monde
À mesure que l’ozone (O3) descend de la stratosphère vers la surface de la Terre, ce bloqueur des rayons ultraviolets cancérigènes devient le troisième gaz à effet de serre en importance et un polluant atmosphérique nocif pour la santé humaine, les écosystèmes végétaux, la sécurité alimentaire et l’économie. L’O3 se déplace de l’atmosphère vers la surface de la Terre par un processus appelé dépôt sec. Les océans couvrent 70 % de la surface terrestre et les dépôts secs océaniques constituent le puits de dépôt le plus important mais le plus incertain, principalement en raison des difficultés à le mesurer. O3-SML combine la modélisation et des observations expérimentales novatrices pour quantifier avec plus de précision les flux de dépôts océaniques mondiaux, ce qui permettra de réduire les incertitudes concernant les dépôts secs d’O3 sur Terre et de nourrir les modèles climatiques pour une meilleure prévision des évolutions futures.
Objectif
Tropospheric ozone is a significant climate gas and has a major influence on air quality, public health, and food security. Ozone is lost to the Earth’s surface directly by “dry deposition”, which is an important loss process for this gas. Since the ocean represents 70% of the surface, uncertainties in the dry deposition to the “sea surface microlayer” (SML) of the ocean translate into large differences in the predicted global ocean dry deposition flux. There has been very limited experimental quantification of ozone deposition over the oceans, because making such measurements is technically very challenging, and estimates of oceanic ozone deposition velocities vary widely. The mechanistic details of the process are incomplete and parameterisations in models are untested against observations. This loss of ozone is acknowledged to be controlled predominantly by chemical reactions in the SML involving iodide and organic material, which not only determine how quickly ozone can be irreversibly taken up at the ocean surface, but may also constitute a source of trace gases to the marine atmosphere. Whilst there is a growing body of work on ozone interactions with oceanic iodide, the nature and reactivity of the organic material in the SML which interacts with ozone is completely unknown. This project will probe both the fundamental mechanisms on and in the SML involved in the loss of ozone and production of atmospherically important trace gases and, in a highly novel and agenda-setting approach, apply this mechanistic information to field observations of oceanic ozone fluxes and the corresponding biogeochemical properties of the SML. This highly interdisciplinary study involves aspects of physical chemistry, atmospheric chemistry, ocean chemistry and physics, and engineering. It transcends conventional boundaries by integrating across atmospheric and ocean science, reflecting the PIs world-leading expertise in field and laboratory science in these fields.
Champ scientifique
- medical and health scienceshealth sciencespublic health
- engineering and technologyenvironmental engineeringair pollution engineering
- medical and health scienceshealth sciencesnutrition
- natural scienceschemical sciencesphysical chemistry
- natural sciencesearth and related environmental sciencesoceanographyocean chemistry
Programme(s)
Thème(s)
Régime de financement
ERC-ADG - Advanced GrantInstitution d’accueil
YO10 5DD York North Yorkshire
Royaume-Uni