Prof. dr. Pieternel Levelt is professor in Remote Sensing of the Earth Atmosphere at Delft University and leads the R&D department on Satellite Observations at KNMI (Royal Netherlands Meteorological Institute). Her main research interests are atmospheric composition and air quality. She is scientific initiator of the TROPOMI instrument on Sentinel 5 Precursor and Principal Investigator of the OMI instrument on NASA's EOS-Aura satellite.