The 2023 burning season in Canada was record breaking. Intense fires started already in May and lasted many months, until October.
In the province of Quebec, the fires were particularly strong, and the smoke plumes dispersed over highly populated regions of the East coast and significantly affected the air quality. HONO was detected by TROPOMI over the complete burning period, with an unprecedented detection rate.
The image shows TROPOMI/Sentinel-5 Precursor observations of HONO (slant columns) over the Canadian fires in Quebec on June 26, 2023, overlaid on the RGB image from the VIIRS/S-NPP sensor.