The structural characteristic of the refractive index of optical waves was calculated from experimental data on the microstructure of the temperature turbulence in the atmospheric boundary layer. The experimental data were obtained with an acoustic meteorological radar (sodar), ultrasonic anemometer–thermometer, and meteorological temperature profilometer. Estimates of the structural characteristics for different conditions in the atmospheric boundary layer are presented and were compared with model profiles.

The height of the mixing layer is a significant parameter for describing the dynamics of the planetary boundary layer (PBL), especially for air quality control and for the parametrizations in numerical modeling. The problem is that the heights of the mixing layer cannot be measured directly. The values of this parameter are depending both on the applied algorithms for calculation and on the measuring instruments which have been used by the data source. To determine the height of a layer of intense turbulent heat exchange, data were used from acoustic meteorological locator (sodar) and from a passive single-channel scanning microwave radiometer MTP-5 (MWR) to measure the temperature profile in a layer of up to 1 km. Sodar can provide information on the structure of temperature turbulence in the PBL directly. These data have been compared with the mixing layer height calculated with the Parcel method by using the MTP-5 data. For the analysis, July and September 2020 were selected in the city of Tomsk in Siberia as characteristic periods of mid-summer and the transition period to autumn. The measurement results, calculations and inter-comparisons are shown and discussed in this work. During temperature inversions in the boundary layer, it was observed that turbulent heat transfer (increased dispersion of air temperature) is covering the inversion layers and the overlying ones. Moreover, this phenomenon is not only occurring during the morning destruction of inversions, but also in the process of their formation and development.

Monitoring measurements of aerosol characteristics and meteorological parameters in the lower atmospheric layer in the winter periods of 2016–2022 in Akademgorodok located in the southeast of Tomsk were used to analyze the conditions for the occurrence of extreme concentrations of submicron particles and black carbon in their composition in the surface layer. It is shown that when surface air temperature inversion and weak (down to 1.5 m/s) wind (air stagnation) occur in combination, the average aerosol characteristics under study increase by as much as a factor of three, and by as much as a factor of 7–8 relative to the seasonal averages in the case of a weak northwesterly wind. It is found that in situations with multiday air stagnation, the typical daily behavior, characterized by the afternoon minimum, changes. The concentrations increase until 15:00 LT up to the values 1.8 times larger than the nighttime minimum. On the other winter days, the maximum occurs at 10:00 LT, with the concentrations of submicron (black carbon) particles being a factor of 1.2 (a factor of 1.5) larger than the nighttime minimum.