The relationship between atmospheric boundary layer and temperature inversion layer and their aerosol capture capabilities

The vertical distribution of aerosols is an important factor in the study of urban environment pollution. However, whether the aerosol is captured by the atmospheric boundary layer or the temperature inversion layer remains unclear. In this study, the relationship between atmospheric boundary layer and temperature inversion layer was investigated based on the micropulse lidar and radiosonde measurements from February 2017 to September 2021 at atmospheric radiation measurement southern great plains site. The results revealed that for each residual layer height (RLH), stable boundary layer height (SBLH) and mixing layer height (MLH), the occurrence frequency of inversion layer within its 0.3 km range is 58, 58 and 68%, respectively. Moreover, the relative error of the MLH, RLH and SBLH relative to the inversion layer height (ILH) under different inversion strength (ΔT) conditions were investigated. The mean relative errors for MLH-ILH, RLH-ILH and SBLH-ILH are −4.13 ± 9.69, −2.26 ± 9.36 and −1.81 ± 15.87%, respectively. The result indicates that the ILH is generally higher than the top of the aerosol layer, and this phenomenon becomes more obvious as the ΔT increased. Finally, the aerosol capture capabilities of different layers are compared. The determination coefficient (R2) between AOD below RLH (MLH) and AOD below ILH are 0.47 (0.58). When the ΔT is larger than 2 °C, the R2 between AOD below RLH (MLH) and AOD below ILH has been obviously improved, increasing to 0.81 (0.90). By contrast, when the ΔT is smaller than 2 °C, the aerosol capture ability of RLH (MLH) is larger (smaller) than that of ILH. It indicates that the temperature inversion intensity is a key factor in determining the aerosol capture ability. These findings have implications for improving our understanding of the vertical distribution of aerosols and its controlling factors. •The temperature inversion intensity is a key factor in determining the aerosol capture ability.•The aerosol capture ability of BL is similar to that of IL under strong inversion conditions.•The inversion layer height is generally higher than the boundary layer height.