EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Aircraft observations of NO2 and NH3 over selected locations in Germany

Lieven Clarisse1, Frederik Tack2, Thomas Ruhtz3, Alexis Merlaud2, Lara Noppen1, Martin Van Damme1, Dirk Schuettemeyer4, Pierre Coheur1, and Michel Van Roozendael2
Lieven Clarisse et al.
  • 1Université libre de Bruxelles (ULB), Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium (
  • 2Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
  • 3Institute for Space Sciences, Freie Universität Berlin, Berlin, Germany
  • 4European Space Agency (ESA-ESTEC), Noordwijk, the Netherlands

Anthropogenic atmospheric emissions of the reactive nitrogen components nitrogen dioxide (NO2) and ammonia (NH3) have majorly altered the global nitrogen cycle in the past 100 years, with devastating consequences to biodiversity, soil, water and air quality. Thanks to effective legislation, NO2 emissions are declining worldwide. Unfortunately, this is not the case for NH3 for which a recent study reports yearly increases of around 2% in Europe and the U.S. and up to 6% in East Asia. 

Both species are currently actively monitored with several satellite sounders, which provide daily global measurements. Yet, the spatial resolution of current sounders is inadequate for resolving the highly heterogonous spatial distributions of both species. This is particularly the case for point source emitters, for which satellites are currently only able to quantify the largest and most isolated ones. To fill the important gap in the monitoring landscape, a satellite called Nitrosat has been proposed in answer to ESA’s Earth Explorer call.  The satellite would allow making simultaneous measurements of NO2 and NH3 at a spatial resolution of 500 meter. In support to the Nitrosat proposal, ESA has funded a project called NITRO-CAM (Nitrogen cycle airborne measurements), which aims at mapping simultaneously NO2 and NH3 in the Greater Berlin area using aircraft measurements. It is the results of this campaign that are presented here. These can be seen as proof-of-concept for Nitrosat, but are also interesting in their own right. A larger focus is given to NH3, for which the presented measurements are the first of their kind.

Campaign flights were performed in the surroundings of Berlin in the autumn of 2020. A follow-up campaign is foreseen in early spring. Measurements are performed with BIRA’s UV-VIS spectrometer newly-developed SWING instrument for NO2 and TELOPS thermal infrared HYPER-CAM for NH3. Surveying gapless areas of at least 10 by 10 km, the measurements enable capturing the emissions of both point and area sources, and are suitable for degrading at various hypothetical satellite instrument footprints.  For NO2 specifically, Berlin and nearby power plants are targeted, while for NH3 the Piesteritz fertilizer factory is targeted, as well as rural areas in the surroundings of Berlin.   

How to cite: Clarisse, L., Tack, F., Ruhtz, T., Merlaud, A., Noppen, L., Van Damme, M., Schuettemeyer, D., Coheur, P., and Van Roozendael, M.: Aircraft observations of NO2 and NH3 over selected locations in Germany, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12645,, 2021.

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