CINDI Field Campaign

From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world have participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI’s Cabauw Experimental Site for Atmospheric Research in The Netherlands.

Its main objectives are to determine the accuracy of state-of-science ground-based measurement techniques, both in-situ and remote sensing, for the detection of atmospheric nitrogen dioxide and to investigate their usability in satellite data validation. It should result in recommendations regarding the operation and calibration of such instruments, retrieval settings, and observation strategies for the use in ground-based networks for air quality monitoring and satellite data validation.

Twenty-four optical spectrometers participated in the campaign, of which twenty-one had the capability to scan different elevation angles consecutively, the so-called Multi-axis DOAS systems, thereby collecting vertical profile information, in particular for nitrogen dioxide and aerosol. Various in-situ samplers simultaneously characterized the variability of atmospheric trace gases and the physical and chemical properties of aerosol particles. A large data set of continuous measurements of these atmospheric constituents has been collected under various meteorological conditions and various air pollution levels. Together with the permanent measurement capability at the Cabauw site characterizing the meteorological state of the atmosphere, the CINDI campaign provided a comprehensive observational dataset of atmospheric constituents in a highly polluted region of the world during summertime.

First detailed comparisons have already been performed and published, notably on slant columns of nitrogen dioxide and the oxygen dimer, on nitrogen dioxide vertical profiles and retrieval methods, on simultaneous in-situ and lidar observations of nitrogen dioxide, and on aerosol extinction measurements. More studies are currently being performed, notably on the comparisons of tropospheric nitrogen dioxide columns, aerosol profiles, ozone profiles and formaldehyde columns, on the spatial variability of nitrogen dioxide and the application of the CINDI data set to satellite data validation in general.

CINDI Home Page

For detailed descriptions of the field campaign, the instruments and incolved and the people behind it please visit the CINDI home page.