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This manuscript investigates the vertical transport and deposition velocities of microplastics in the atmosphere through wind tunnel experiments, providing important insights into the environmental behavior of microplastics. The study employs a controlled wind tunnel environment and advanced measurement techniques to produce key results on the concentration gradient and deposition velocity of microplastics at different altitudes. The experimental results show that microplastic deposition is influenced by wind speed and turbulence, while having similar deposition velocities to mineral particles. These findings help fill gaps in the understanding of the environmental behavior of microplastics and support the use of existing models to assess the transport of microplastics in the atmosphere. In this manuscript, the experimental data are valuable, the measurement methods are reliable, the article logic is clear, and the references are appropriate. The manuscript deserves publication after the authors take care of the following moderate revision described below.

1. In section 2.2, is there a more accurate quantification of the 3.9 x 10⁹ particles per ml obtained by the authors after dilution, or is it solely an estimation based on the manufacturer's provided concentration during microplastics purchase? How does the authors control the uncertainty of the microplastic concentration in the suspension?
2. In lines 110 to 113, was there an omission of a negative sign in Equation 4 when it was derived from Equation 3?
3. In line 116, “-2” should be superscripted.
4. In lines 166-167, the authors state that microplastics in the accumulation mode are transported vertically in a similar way to other particles that may be denser in the accumulation mode. Is it possible to make a detailed comparison directly in the manuscript, which could be a more visual figure?
5. The conclusion section could further explore the environmental behavior of microplastics in the atmosphere in relation to other environmental factors to deepen the understanding of the mechanisms of microplastic transport and deposition in the atmosphere.