Paving the way for space-based observations of reactive nitrogen

The ESA-funded NITROCAM campaigns, coordinated at BIRA-IASB, focus on the simultaneous measurement of the most important reactive nitrogen compounds in the atmosphere, nitrogen dioxide (NO2) and ammonia (NH3), which are at the root of a wide range of environmental problems. These campaigns are organised in preparation of NITROSAT, a satellite dedicated to making high-resolution observations (500 m) of nitrogen pollution sources. It is in the running to become ESA’s 11th Earth Explorer mission.

Nitrogen dioxide is a harmful air pollutant and a precursor of ozone and particulate matter. Ammonia is not directly harmful for human health at ambient levels, but is a key precursor of fine aerosol particle pollution. Both compounds are linked to climate change through interactions between the natural carbon and nitrogen cycles.

What is NITROSAT?

The NITROSAT Earth Explorer will be the first dedicated satellite mission to simultaneously identify the emission contributions of NH3 and NO2 from farming activities, industrial complexes, transport, fires and urban areas at high spatial resolution (500 m).

It will foster the assessment of the processes that are relevant for the human disruption of the nitrogen cycle and their resulting effects. In this way, NITROSAT will enable informed evaluations of future policies on nitrogen emission control.

What is NITROCAM?

NITROCAM is a set of ESA-funded airborne measurement campaigns dedicated to the preparation of the NITROSAT mission and performed by the airborne team at BIRA-IASB, in cooperation with Freie Universität Berlin (FUB) and with the Université Libre de Bruxelles (ULB).

The airborne team at BIRA-IASB is responsible for the coordination of the campaigns as well as for the SWING whiskbroom imager to make local measurements of the NO2 horizontal distribution under the aircraft. Besides SWING, a TELOPS HyPER-Cam LW from the German Centre for Geosciences (GFZ) is integrated to measure NH3 in the thermal infrared.

Together, the instruments can be seen as an airborne demonstrator for the future NITROSAT space mission. The spatial resolution of the collected data will be resampled as if it was collected from space and specifications like the sensitivity etc. will be assessed.

The first scientific flights took place in Germany in fall 2020 and spring 2021, and already enabled a first joint detection of NH3 and NO2 from an industrial site. In May and June 2022, the campaign focused on the Po valley, which is interesting in particular for its good weather statistics and strong levels of NO2 and NH3 due to traffic, industry and agricultural activities.

A follow up campaign will be organized over Northern Italy in spring 2023, in collaboration with Kings College London (KCL), British Antarctic Survey (BAS) and NASA.

 

Reference

Noppen, L., Clarisse, L., Tack, F., Ruhtz, T., Merlaud, A., Van Damme, M., Van Roozendael, M., Schuettemeyer, D., Coheur, P.: Constrining Industrial Ammonia Emissions Using Hyperspectral Infrared Imaging, Remote Sensing of Environment, in review, 2022.

NH3 and NO2 over Piesteritz fertilizer plant Germany
Simultaneous retrieval of NH3 and NO2 over the Piesteritz fertilizer plant (Germany) during a flight on 28/04/2021.