The lidar ratio (LR) is a key parameter for the retrieval of atmospheric optical parameters from lidar equations. In this study, we simulated the optical parameters to investigate the impact factors of the LR using a three-component optical aerosol assumption based on the Mie model. The simulated LR was generally related to the overall particle size of the aerosols, the proportion of elemental carbon (EC), as well as aerosol mixing states and hygroscopicity. The LR was positively correlated with the particle size and volume fraction of elemental carbon (f_EC). The LR increased more than three-fold with the increase in f_EC from 0% to 40%. The LR of the core-shell (CS) mixing state and homogeneously internal (INT) mixing state was greater than that of the external (EXT) mixing state. The LR of all mixing states increased monotonically with hygroscopicity when the f_EC was below 10%, while the LR of the core-shell mixing state (homogeneously internal mixing state) initially decreased (increased) and then increased (decreased) with increasing hygroscopicity when the f_EC was more than 20%. These results will help in selecting a reasonable LR for practical applications.

A number of studies have brought up that turbulent transport dissimilarity between momentum and scalars, and even among scalars, is a distinct feature of the unstable boundary layer, affecting the performance of the Monin–Obukhov similarity theory. Although the source/sink distribution of scalars, as well as the top‐down entrainment processes, are identified as being responsible for affecting transport dissimilarity, less is known about the role of bulk‐shear‐generated non‐local large eddies. Using data collected by an eddy covariance system mounted on a 70‐m meteorological tower over a complex rural area, decreased transport dissimilarity with enhanced wind shear is observed during daytime unstable conditions, prompting our interest in the underlying governing mechanisms. Enhanced wind shear increases the intensity of coherent large eddies, with spectra analysis confirming that large eddies with scales larger than 0.3 (in the normalized frequency) are mainly responsible for the enhanced correlation of fluxes. Moreover, this process is operating on large eddies with minimal phase differences. With enhanced wind shear, fluctuations of scalars within these non‐local large eddies become synchronous. Due to the enhanced ejections of large eddies under strong wind shears, fluxes are transported evenly, thereby resulting in decreased transport dissimilarity.