This study conducted field measurements of atmospheric aerosol and gaseous species across three urban sites in Eastern China, by employing an integrated approach combining aerosol thermodynamic modeling with machine learning techniques to evaluate the role of dust in modulating aerosol pH and its subsequent effects on nitrate formation. The findings demonstrate that dust composition and ammonia variability constitutes the dominant control on aerosol pH. During dust storm, elevated concentrations of non-volatile cations significantly enhanced aerosol alkalinity, thereby promoting particulate nitrate formation. These processes simultaneously diminished the  sensitivity of the aerosol pH to ammonia emission reductions. Overall, the manuscript is well written and the results are valuable to the literature. While the conclusions provide valuable insights, several aspects warrant further clarification.

General comments:

1. Lines 98-99: Please specify the effective particle size capture range of the wet sample, and the corresponding collection efficiency.

2. Lines 233-236: Is sulfate volatile? It could simply be because the fraction of nitrate decreased, causing that of sulfate to increase relatively. In addition to the effects of atmospheric dilution and dispersion, could the differences in dust composition from various sources also play a role?

3. Line 290: What scientific rationale underlies the specific concentration thresholds (0, 0.7, 3 ug m^-3) adopted for classification purposes?

4. Lines 297-299: While the impact of Ca2+ is demonstrated, were other cations (e.g., Fe and Mn) similarly evaluated? 

5. Figure 6: In Figure 6b, there is no change in aerosol pH when the sulfate concentration is below approximately 5 µg m⁻³. Could you please clarify the reason for this?

6. Lines 357-358: Any reason? Is it due to the different composition of the dust or different environmental conditions?

7. Lines 370-371: The interpretability of the random forest model's predictions requires further clarification. For reductions ranging from 0% to 50%, do the concentrations of each species remain within the observed range after reduction? If not, the random forest model may fail to accurately capture the relationship between the predictors and the dependent variables, potentially leading to misinterpretations.

Technical comments:

1. Figure 7: Please add into the figure typical pH values for non-dust periods for better clarity.

2. Lines 258-260: Add “for example” before this sentence to improve flow.

3. Please standardize all chemical notation with proper subscript/superscript formatting.

The manuscript explores the impact of dust pollution on aerosol pH and nitrate gas-particle partitioning. By combining field observations, thermodynamic modeling, and machine learning techniques, this study provides a comprehensive analysis of how different dust scenarios affect urban aerosol pH and gas-particle partitioning chemistry of nitrate. I would consider the publication of this article once the authors have addressed the following comments.

Specific comments:

1. (English) The language and grammar of the manuscript should be improved.

In some of these instances, bad grammar prevents understanding the main point of the sentence.  I will point in the minor comment section to these parts of the text, with a recommendation on how to change the text, based on my understanding of what the main point of it is.

1. L. 47: “Dust particles also engage in heterogeneous reactions with gaseous nitric acid, buffering acidic species and modulating pH dynamics.” This is a priori reasonable description, due to the alkalinity of carbonate minerals. It would be good to have references here to support it. A recently published article in EST provides a thorough explanation of how aerosol acidification responds to the buffering capacity of carbonate minerals during Asian dust storms (https://pubs.acs.org/doi/10.1021/acs.est.4c12370).
2. L. 71: Replacing “East Asia, home to some of the world's major dust source regions” with “East Asia, which contains some of the world's major dust sources, significantly contributes to global atmospheric dust pollution”
3. L.75: “atmospheric setting” to “atmospheric experiment”
4. L. 231-236: The authors claim that the abundance of nitrate in aged dust particles during long-range transport dust storms was higher than during local dust periods, whereas sulfate abundance was greater during local dust periods than in long-range transport dust storms. You attribute this to the stronger atmospheric dilution and dispersion effects on nitrate during dust storms. You mean that long-range transport dilutes nitrate? If so, a decrease in nitrate contribution should be observed along the dust transport from Xuzhou to Zhenjiang to Suzhou.

In reality, however, Ca(NO₃)₂ and Mg(NO₃)₂ coatings preferentially form on aged mineral particles containing calcite and dolomite. Moreover, the number of Ca(NO₃)₂-coated particles increases with dust transport distance due to the relatively low deliquescence relative humidities (>11%) (see Li et al., ACP, 2009, https://doi.org/10.5194/acp-9-1863-2009; Tobo et al., PNAS, 2010, http://www.pnas.org/cgi/doi/10.1073/pnas.1008235107; A. Laskin and T. W. Wietsma, JGR-A, 2005, doi:10.1029/2004JD005206). Given that calcite and dolomite are widely present in Asian dust particles, it is expected that during the dust storm period, the relative contribution of Ca²⁺ and Mg²⁺ increased across all three cities, with an average rise of approximately 10% compared to the local dust period. (your Figure 3)

Therefore, the authors should thoroughly study more relevant literatures to provide a more reasonable explanation. Furthermore, the higher sulfate content in long-range transported dust particles likely originates from the presence of weakly soluble CaSO₄.

1. L. 318: “During dust storms, the mean aerosol pH values were 5.50 ± 1.65 in Xuzhou, 5.44 ± 1.69 in Zhenjiang, and 5.30 ± 1.67 in Suzhou. Under local dust conditions, these values were lower, at 4.12 ± 0.52, 3.92 ± 0.32, and 3.74 ±0.69 respectively.” As the author pointed out, dust particles were more acidified by more secondary acidic aerosols (SO₄^2-, NO₃^-) formed on dust surfaces along with dust long-distance transport, eventually leading to the decrease of pH. However, why does a similar trend also appear during local dust events?
2. L. 359: “This indicates that dust storm conditions have a significantly stronger positive contribution to the particle-phase fraction of nitrate. The presence of dust particles facilitates the conversion of nitrate to the particulate phase, highlighting the significant influence of dust storms on nitrate partitioning in the atmosphere.” Does this contradict the previous description of stronger atmospheric dilution and dispersion effects on nitrate? similar to Comment 5
3. Figure 9: Please label the different dust pollution conditions along with Ca²⁺ concentrations in the figure.