Objetivo Air trapped in polar ice cores provides a unique archive of atmospheric composition in the past. However, reactive gases are not stable in ice core air, and therefore no paleo-proxies exist that allow reconstructing the oxidation capacity of the past atmosphere from ice cores. Recent study shows that isotope exchange between highly reactive oxygen atoms (O(3P)) and relatively non-reactive O2 in the atmosphere imprints an isotope signal in the “clumped” isotopic composition of atmospheric O2, which can be a tracer for the abundance of O(3P) in the troposphere. Clumped isotopes are isotopologues containing more than one heavy isotope (e.g. 18O18O), and they are now detectable at high precision using modern technology. I propose here to develop these novel clumped isotope measurements on O2 into a tool to reconstruct the oxidative capacity in the past atmosphere from O2 trapped in firn and ice core air. I will first verify the hypothesis that the large clumped isotope signal originates from fast O(3P)+O2 exchange at low temperatures in the stratosphere, and that this signal is only partially erased by further exchange in the troposphere, where much lower O(3P) and higher temperatures prevail. Clumped isotope analyses on O2 trapped in ice cores will then be used to decipher past variations in atmospheric oxidation processes with a temporal resolution of decades to millennia. I am particularly interested in determining the effects of both natural (glacial-interglacial) climate variability and anthropogenic climate change associated with fossil fuel combustion on oxidation processes in the atmosphere. My experience in the field of clumped isotopes fits perfectly to the expertise of the host group in atmospheric research using isotopes, and the project will make use of the new world-leading high precision isotope ratio mass spectrometer MAT 253 ULTRA facility that will enable measurement of all 6 isotopologues of O2, including the rarest one, 17O17O, for the first time. Ámbito científico natural scienceschemical scienceselectrochemistryelectrolysisengineering and technologyenvironmental engineeringenergy and fuelsnatural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changesnatural sciencesearth and related environmental sciencesatmospheric sciencesmeteorologytroposphere Programa(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Tema(s) MSCA-IF-2016 - Individual Fellowships Convocatoria de propuestas H2020-MSCA-IF-2016 Consulte otros proyectos de esta convocatoria Régimen de financiación MSCA-IF-EF-ST - Standard EF Coordinador UNIVERSITEIT UTRECHT Aportación neta de la UEn € 177 598,80 Dirección HEIDELBERGLAAN 8 3584 CS Utrecht Países Bajos Ver en el mapa Región West-Nederland Utrecht Utrecht Tipo de actividad Higher or Secondary Education Establishments Enlaces Contactar con la organización Opens in new window Sitio web Opens in new window Participación en los programas de I+D de la UE Opens in new window Red de colaboración de HORIZON Opens in new window Coste total € 177 598,80