First experiment on high-detailed mapping of tropospheric NO2 in polluted areas using GSA hyperspectral imager

Nitrogen dioxide content in the atmosphere is routinely retrieved by OMI with spatial resolution of 13x24km. Since December 2018 TROPOMI provide data with better resolution of 7x7km what improve opportunity of understanding small-scale processes characteristic of antropogenic pollutions. Space agencies expect to start develop satellites after 2020 with resolution about 2km.

An alternative to GEO satellites may be a constellation of small satellites with even higher resolution of approximately 0.5-1km carrying out regular measurement and monitoring of emission sources of NO2 in lower troposphere.

We performed the first experiment on high-detailed retrieval of NO2 field in the troposphere using measurements of hyperspectral imager GSA which is one of small payload on board of Russian satellite Resurs-P. GSA resolves more than 230 spectral bands from 400 nm to 1000 nm and cover area of 30-km width with spatial resolution 120m. The main goal of the instrument is natural resource investigation. We developed an algorithm which use GSA data for determing the content of NO2 in the lower troposphere on a grid with a step of 120m. NO2 retrieval error become comparable to ones obtained by other satellite instruments, when resolution of GSA is about 2 km.

For the first time local sources of NO2 pollution and their plumes were identified. The first results are presented for measurements performed in 2016 over Hebei province of China which is one of the most NO2 polluted regions in the word. The study was supported by Russian Foundation for Basic Research by grants 18-29-10080, 18-35-00682.