Nitrogen dioxide (NO2), part of the General group of oxides of nitrogen (NOx) is a major component of air pollution in the urban environment. It is formed by high temperature combustion. The main anthropogenic (human-made) sources of emissions of this harmful substances are gas and coal power plants and urban transport. In addition, there are natural sources of NO2 emissions, e.g., forest fires, and lightning, but their role against the background of emissions is minimal.
Using satellite imagery and machine learning algorithms company Labs Descartes visualized the emissions of nitrogen dioxide in the atmosphere. Elevated concentrations of NO2 can stimulate acid rain, smog, and reduce the rate of revegetation of the planet, as well as a variety of health problems in the population. Is a strong corrosive substance and irritates the nasal cavity and eyes. At concentrations over 150 ppm. causes bronchitis, and more than 500 ppm. — pulmonary edema,the effect lasted only a few minutes.
The data for the images was obtained by the Sentinel 5P satellite, which was launched in October 2017 for monitoring the atmosphere of the planet. It is part of the constellation of satellites of the European space Agency that are used for Earth observation. In particular, other satellites engaged in the observation of vegetation and land use, global temperature change and even the tracking of cracks in the ice cover of Antarctica.
The above map is part of a series of images of the main sources of NO2 on the planet prepared by Descartes Labs in February. According to Tim Wallace, head of the Department of graphic design Descarte Labs, for its creation was used a number of separate images that were obtained using Sentinel-5P in the period from August to September 2018. For a more precise and clear display of the distribution of nitrogen dioxide on the planet from the sample was excluded low-quality pictures as well as images of regions in cloudy and dull weather.
Typically, the nitrogen dioxide lingers in the atmosphere for a very long time, which eliminates the possibility of a wider distribution from emissions. Therefore, it is obvious that the main concentration of emission near the cities, where a large number of cars. At the same time, the map is quite noticeable single sources, said Wallace, adding that we are talking about ships and some industrial cities.