Tropospheric ozone distributions over Europe during the heat wave in July 2007 observed from infrared nadir spectra recorded by IASI

First partial tropospheric ozone columns (0–6 km) derived from radiances observed by the IASI instrument aboard the MetOp‐A platform over Europe during summer 2007 are presented. They were retrieved using an altitude‐dependent regularization method. Comparison with measurements from balloon sondes shows excellent agreement. Space‐borne observations show large lower tropospheric ozone amounts over South‐Eastern Europe during the heat wave period, which are also displayed by simulations with a regional chemistry‐transport model CHIMERE.