Temperature inversion intensifies, PM2.5 levels exceed norms – Uzhydromet

Following recent precipitation and amid relatively warmer air temperatures, atmospheric inversion processes have intensified again in Uzbekistan, Uzhydromet reported.

Temperature inversion is a natural phenomenon in which cold air remains near the ground while warmer air settles above it, preventing air layers from mixing. As a result, fine particulate matter accumulates in the lower atmosphere, leading to a rapid increase in concentration levels.

This process has become particularly pronounced in several regions of the country, including Tashkent, as well as Samarkand and Jizzakh regions. It is especially evident during morning, evening, and nighttime hours, when air exchange in the lower atmospheric layers becomes limited. Consequently, unfavorable meteorological conditions are forming, making it difficult for pollutants to disperse.

According to Uzhydromet, due to its natural and geographical location, terrain features, and prevailing synoptic conditions, Uzbekistan generally falls among regions where atmospheric inversion occurs frequently and almost continuously.

Preliminary forecasts indicate that the warm weather and inversion conditions across the country are expected to persist until the end of the week.

As of 9:00 a.m. on December 23, data from automatic air pollution monitoring stations showed the following levels in Tashkent’s atmospheric air:

• PM10 fine particulate matter concentrations reached 87 µg/m³, which did not exceed the permissible limit of 300 µg/m³;
• PM2.5 fine particulate matter concentrations amounted to 64 µg/m³, exceeding the permissible level of 60 µg/m³ by 1.1 times.