A fresh map of nitrogen dioxide emissions to the atmosphere is presented.

Nitrogen dioxide (NO2), included in the general groupnitrogen oxides (NOx), is a major component of air pollution in an urban environment. It is formed as a result of high-temperature burning. The main anthropogenic (man-made) sources of emissions of this harmful substance are gas and coal power plants, as well as urban transport. In addition, there are natural sources of NO2 emissions, for example, forest fires, as well as lightning, but their role in the general background of emissions is minimal.

Using satellite imagery and algorithmsMachine Learning Descartes Labs has visualized emissions of nitrogen dioxide into the atmosphere. Increased concentration of NO2 can stimulate acid rain, could, reduce the rate of renewal of the vegetation of the planet, as well as a variety of health problems among the population. It is a strong corrosive substance and strongly irritates the nasal cavity and eyes. At a concentration of more than 150 ppm. causes bronchitis, and over 500 ppm. - pulmonary edema, even if the exposure lasted only a few minutes.

Data for images were obtained usingsatellite Sentinel 5P, launched in October 2017 to monitor the atmosphere of the planet. It is part of the European Space Agency satellites constellation, which are used to observe the Earth. In particular, other satellites are engaged in observing vegetation cover and land use, changing global temperature and even tracking cracks in the ice cover of Antarctica.

The above map is part of a series.images of the major NO2 foci on the planet, prepared by Descartes Labs in February. According to Tim Wallace, the head of the graphic design department at Descarte Labs, many individual images were used to create it, which were taken with the help of Sentinel-5P from August to September 2018. For a more accurate and clear display of the distribution of nitrogen dioxide on the planet from the sample were excluded low-quality photographs, as well as images of regions in cloudy and cloudy weather.

Normally nitrogen dioxide is retained in the atmospherea very long time, which excludes the possibility of its wider distribution from the point of emission. Therefore, it is obvious that the main concentration of its emissions is located near cities where a large number of cars are used. At the same time, single sources are quite noticeable on the map, Wallace said, adding that we are talking about ships and individual industrial cities.

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