Dust removal by snow is an important mechanism for dust wet deposition, which not only modifies atmospheric dust residence time but also helps the understanding of dust-snow interactions and dust-in-snow effects. Till now, it is still challenging to accurately estimate dust removal by snow. This study has developed a Euler-Lagrange numerical modeling framework to simulate and analyze snow particles motions and dust collection in turbulent boundary layers. It also proposes several equations for estimating dust removal by snow, which can be used for large-scale numerical models. Most of the manuscript is well written. I have some comments for further improvements of the manuscript.

Main comments:

• The results are derived based on several assumptions including spherical shape for snow particles and very small size (<20 nm) for dust particles. It is better to add a sentence to mention the assumptions before the description of the results in both Abstract and Conclusions. In addition, it might be better to also add some discussions on the impact of these assumptions on the applications of current results presented. In particular, the dust size is too small compared to commonly-used size range (the orders of 0.1-10 micrometer) in atmospheric models. I am wondering how the conclusions (e.g., optimal scavenging efficiency by snow partiles in a diameter of 100–150 μm) and equations derived for dust collections can be applied in this range.
• Several equations are provided with values for parameters shown, such as Eqs. 16, 18, 19, 22, 27, 29. In these equations, it is suggested that the units for variables (and parameters) are provided as well, as the values can change if the units for the variables are changed. Please check the units throughout the manuscript to avoid such confusion.

Specific comments:

• Line 10: quiescent atmosphere: not clear.
• Lines 10-11: neglecting…, affecting…: not clear.
• Line 20: "it" is not clear.
• Line 26: also contributing: changed to “they also lead to”?
• Line 27: variations in dust concentrations: add “in the downstream regions” after it?
• Line 30: source aerosols?
• Line 33: episodic?
• Line 57: “(Langmuir, 1948)” changed to “Langmuir (1948)”.
• Line 76: dynamical?
• Line 85: after “motions”, add "trajectories"?
• Section 2: It is better to provide an overall description on how each method are used and combined to have results shown in Section 3. I am confused with that.
• 3 and 4: How about i and j?
• Line 106: Change “P” to “p”?
• Line 107: RANS/LES: full name?
• Line 132: <10^-6: Supposing a certain falling velocity and a typical snow density, what is the snowfall rate equivalent to this value? I am wondering if the snowfall rate is at a similar magnitude as the realistic cases?
• 10-12: What are Ap and uf?
• Line 144: escape: It is not clear to me.
• Line 147: diameter range: For easy reading, it is better to explicitly mention the diameter range here.
• Lines 148-149: Changed to "we obtained xxx"
• Table 1: and different Dp conditions.
• Line 159: h=0.04m: what is h?
• Line 162: velocity data are reintroduced?
• Line 202: What is k?
• Line 215: Please explain how turbulence intensity is defined.
• Figure 5: At which moment?
• Line 229: larger-diemeter: lease add the range of diameters explicitly to make it clear.
• Line 239: Please clarify whether this function is suitable for snow particles.
• Figure 7: Please check if there are identical results (trajectories) for u*=0.75 m/s and Dp=500 μm in Fig. a and Fig.b.
• Lines 247-249: Please also add the information in Fig.8 for easy viewing. Please also explain what "mag" is in Fig.8.
• Figure 9: Please check if there are identical results (PDF) for u*=0.75 m/s and Dp=500 μm in Fig. a and Fig.b. Probably use same color (e.g., black) for this case to facilitate the comparison.
• Line 280: fitting parameters: For easy understanding, could you also write down the equation and indicate what a and b mean?
• Line 282: fitting parameters: For easy understanding, could you also write down the equation and indicate what b1 means?
• Liness 290-291: ra and rs: It is better to use individual lines for these equations.
• Line 299: It is better to use individual lines for these equations.
• Line 310: dimensionless settling time: Please explicitly mention what this means for easy understanding.
• 22: =Vr=?
• Line 323: Use a new paragraph for easy reading.
• Line 330: add a space before “due”.
• Line 352: I think the concentrations may be too small.
• Line 352: Dp<20 nm: Actually, such small dust particles are poorly studied and known. Please clarify whether it is reliable or meaningful to have this assumption.
• Figure 17 captions: Please explain what Q1 and Q2 are. Please also what dash means indeed.
• Line 377: (Q1+Q2)/Q is not equal to 100%?
• 26: I am not wondering how Qu* and Q0 are related to Q1 and Q2.
• Line 389: add “As shown in Fig. 19,” before “the”.