Under calm and steady weather conditions with low wind speeds, turbulent intermittency frequently occurs in the atmospheric boundary layer (ABL), which can significantly weaken the turbulent diffusion of matter and energy between the surface and atmosphere. The turbulence barrier effect is defined as the phenomenon in which turbulence may disappear at certain heights, and during periods of heavy haze, creating what can seem like a barrier layer that hinders vertical transmissions. Although the turbulence barrier effect can explain the physical mechanisms behind the rapid accumulation of PM_2.5 (fine particulate matter with diameters smaller than 2.5 μm) and the influence of turbulent diffusion conditions on the vertical distribution of PM_2.5, more direct perspectives such as turbulent flux is still required for quantitative verification. Due of challenges in the acquisition of PM_2.5 turbulent flux, carbon dioxide (CO₂), which has relatively mature flux acquisition technology, was used as a substitute means of verifying and quantifying this phenomenon. The turbulence data collected during heavy haze events, at from five levels of a 255 m meteorological tower located in Tianjin, were analyzed and used to quantitatively verify the influence of the turbulent barrier effect on PM_2.5. The results also revealed that the vertical changes in the turbulent barrier effect were consistent with those of the concentrations and flux of CO₂. This means that this knowledge about the turbulent barrier effect can be extended to other mass-transfer processes. The analysis also found that the proportion of counter-gradient transport increases when the occurrences of the turbulent barrier effect are frequent. This work validates the presence of the turbulent barrier effect and is an important foundation for its future parameterization, which will help to accurately identify the matter transport processes in the stable boundary layer and under extreme weather conditions, such as intense pollution events.

In a stable boundary layer (SBL), turbulence is generally weak and exhibits significant intermittent characteristics. Interactions among motions of different scales complicate its structural evolution, making prediction challenging. This study focuses on two typical processes in the SBL: low‐level jet (LLJ) and internal gravity waves (IGWs), investigating how their interactions influence the evolution of turbulence structures. Utilizing a full boundary layer turbulence observation network and data processing system at Zhongchuan International Airport, this study includes eddy covariance system, Doppler Lidar, and wind profiling radar. In strongly SBL, turbulence energy accumulates in higher layers and, during downward transfer, generates local LLJ and IGWs, triggering intermittent turbulence events. Internal factors of turbulence intermittency dominated the process. The interaction between LLJ and IGWs maintains intermittent turbulence bursts, accompanied by the conversion of sub‐mesoscale energy to turbulent energy. In weakly SBL, the conversion of sub‐mesoscale motion energy drives intermittent turbulence events, along with energy transfers between different scales of IGWs, resulting in weaker turbulence intermittency. External factors of turbulence intermittency dominated the process. In both cases, the interaction between LLJ and IGWs alters turbulence structure and atmospheric stability. Turbulent mixing changes the mean gradient field, further influencing the LLJ height. This study elucidates the mechanisms of interaction between internal and external factors in turbulence intermittency. It outlines energy transfer among different scales of motion and clarifies the mechanisms behind state transitions and structural evolution in strongly and weakly SBL. These findings are significant for advancing theoretical research and simulation developments of the SBL.