2011-12-15: Phd defense of Tim Vlemmix

On Thursday, December 15, Tim Vlemmix succesfully defended his PhD-thesis 'Tropospheric Nitrogen Dioxide Inversions based on Spectral Measurements of Scattered Sunlight' at the technical university of Eindhoven.
The thesis describes a method to measure columns and simplified profiles of tropospheric nitrogen dioxide (NO2) with a MAX-DOAS instrument (see photo). The MAX-DOAS instrument was placed on the roof of the KNMI building for 14 months, which yielded a unique set of observations. The data were compared with the NO2-lidar from the RIVM, satellite observations from the OMI-instrument and the air-quality model Lotos-Euros. The comparisons showed that MAX-DOAS measurements are very suitable for validation purposes. The observations can be done automatically, and because of the low costs this type of instrument is very suitable for a (European) network.
During the CINDI campaign in 2009, three mini MAX-DOAS instruments were installed at 20 meter altitude on the KNMI measurement tower in Cabauw. The middle instrument is the instrument used in the research.