The photochemical production of lowermost tropospheric ozone (located below 3 km of altitude) was quantified for the first time only using satellite data (Cuesta et al., 2018). This is the first daily quantification made so close to the surface, and therefore being directly related to air quality. These results were obtained with the only satellite method currently capable of observing ozone at the lowermost troposphere, based on the synergism of infrared and ultraviolet measurements of respectively the IASI and GOME-2 sounders. Using these so-called IASI+GOME2 ozone observations, the amount of lowermost tropospheric ozone produced while travelling across East Asia has been estimated to be more than 80% of the ozone concentrations originally formed in China as a result of major precursor emissions. These new scientific findings from researchers of the Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA / IPSL, CNRS / UPEC / Paris Diderot University) and the Japan Agency for Marine-Earth Science and Technology (Japan) will provide a new characterisation of the origin of ozone pollution and its export across geographical boundaries. Produced globally in near real time, the IASI+GOME2 ozone space observations are available for the international community by the AERIS French national data centre (




These research work benefited from financial support from the Partenariat Hubert Curien Sakura, CNES, PNTS and ANR, and datasets provided by EUMETSAT, AERIS, NOAA CLASS portal and LATMOS-IPSL/ULB (CO IASI observations).