Following the drastic reduction in road traffic due to lockdown in France, a reduction of more than half of the nitrogen oxide concentrations in the Parisian atmosphere was noted by the Airparif network of measurements. On the other hand, fine particles are still very present.
Two peaks of particle pollution have been observed in Paris for the days of March 20-21 and March 27-28, 2020. These particles are emitted directly by road traffic and wood heating, but they can also be formed from NOx and ammonia (NH3) present in the atmosphere.
Recently, a team of the Laboratory Atmospheres and Space Observations (LATMOS) has set up an instrument, called mini-DOAS for « Differential optical absorption spectroscopy », on the roof of Sorbonne University within the QUALAIR platform to monitor NH3 concentrations over Paris in real time.
Thanks to this new dataset, scientists were able to observe the simultaneous appearance of peaks of NH3 and fine particles and thus confirm the role of agricultural activities on the deterioration of air quality in Paris.