Ilann's current research focuses on the sources, transport, reactivity and air quality impact of nitrogen species (e.g., NOx, HNO3, PAN, HONO) and ozone (O3). Nitrogen oxides (NOx) are principally emitted by combustion sources, both natural (wildfires) and anthropogenic (fuel combustion) and are primarily responsible together with volatile organic compounds (VOCs) for the formation of O3. O3 is a secondary air pollutant of particular concern for air quality in most major urban centres on Earth, and also for climate owing to its significant contribution to the global radiative balance.