National Institute of Geophysics, Geodesy and Geography-
Bulgarian Academy of Science
National Institute of Meteorology and Hydrology





Nitrogen Dioxide (NO2) Ozone
Sulfur Dioxide
Fine Particulate Matter(PM10) Fine Particulate Matter(PM2.5) Air Quality Index
Dominant pollutant (DPI) Universal Thermal Climate Index (UTCI)

Within the framework of the National Scientific Program " Environmental Protection and Reduction of Risks of Adverse Events and Natural Disasters" funded by the Ministry of Education and Science, the System for Chemical Weather Forecast (air pollution) was created. The System present the 72 hours forecast for air pollution in real-time, starting from 00:00 of the current day and extending two more days ahead for the territory of Bulgaria, with a spatial resolution of 3 km and for three selected cities - Sofia, Plovdiv, and Varna, with a resolution of 1 km each.

For each of the mentioned domeins, one of the five main pollutants can be selected - Nitrogen Dioxide (NO2), Ozone (O3), Sulfur Dioxide (SO2), Fine Particulate Matter with a diameter below 10 µm (PM10), Fine Particulate Matter with a diameter below 2.5 µm (PM2.5), from which the Air Quality Index (AQI) is calculated and visualized. The system also forecasts the Universal Thermal Comfort Index (UTCI), indicating the thermal comfort/discomfort of the human body.

Dominant pollutant (DPI):

0-1: Nitrogen Dioxide (NO2)
1-2: Ozone (O3)
2-3: Sulfur Dioxide (SO2)
3-4: Fine Particulate Matter (PM10)
4-5: Fine Particulate Matter (PM2.5)