I have carefully reviewed the manuscript entitled “The impact of tropical cyclones on regional ozone pollution and its future trend in the Yangtze River Delta of China”. While the topic is of potential interest and relevance, particularly in the context of climate change and regional air quality, I cannot recommend publication in its current form. The manuscript suffers from multiple major flaws in methodology, presentation, data interpretation, and referencing, which severely undermine its scientific credibility. I therefore recommend rejection, although a substantially revised version may be reconsidered as a new submission. My major and specific concerns are listed below.

Major concerns:

1. The authors identify five synoptic weather patterns (SWPs) using a rotated principal component analysis (PTT method), but they do not provide adequate information on the physical characteristics of these SWPs or justify the use of different meteorological parameters and domains in defining their intensities (Lines 167–171, 259–264).

Furthermore, Table 1 suggests that some SWPs primarily occur in winter, spring, and autumn, while SWP2 and SWP5 dominate in summer. This implies a strong seasonal signal embedded in the classification. However, the authors proceed to analyse O₃ pollution impacts without removing seasonal cycles, which is inappropriate given the strong seasonal variability in both O₃ precursors and photochemistry. Weather pattern classification should be conducted on seasonally detrended data to avoid conflating synoptic and seasonal influences.

2. Many key numerical conclusions lack both graphical support and proper referencing (e.g., Lines 394–404, 436–438). For instance, the stated contributions of SWP5 to O₃ concentration changes—15.14% in 2030 and 20.66% in 2060—are not clearly contextualised. These values appear to indicate that SWP5 is the most influential within those respective years compared to other years, rather than compared to other weather patterns. However, the manuscript does not clearly define the comparison baseline, which may mislead readers into interpreting these percentages as reflecting the dominance of SWP5 over other synoptic types. Clarification is essential to avoid misinterpretation.

Several critical results, such as the contribution index and the role of TC-generated meteorological conditions (e.g., "low humidity and strong solar radiation"), lack quantitative evidence (Lines 309–311). This weakens the entire discussion on the role of TCs in driving O₃ changes.

3. Throughout the manuscript—particularly in the introduction—numerous claims are either incorrectly cited, misrepresented, or not supported by the referenced sources. This significantly undermines the scientific credibility and rigour of the work.

Here are some examples, lines 38–40: The statement that O₃ accounted for over 50% of polluted days is not substantiated by the referenced China Ecological Environment Bulletin. The authors should provide the correct citation, improve the clarity of the English, and revise the conclusion to reflect the actual content of the report.

Lines 77–80: Assertions regarding the low-frequency modulation of tropical cyclones (TCs) by climate change are made without any credible or peer-reviewed references.

Lines 86–88: The claim that TC frequency in the Northwest Pacific has decreased, while intensity and duration have increased, is not convincingly supported by the cited literature. In fact, some references appear to be news media or secondary summaries rather than original peer-reviewed scientific studies.

Specific Comments

1. Line 50: Please spell out "TC" at first mention.

2. Lines 190–192: Claims on O₃ variation lack data or plots. Add evidence.

3. Lines 213–217: The description of two TC-O₃ response types is unsupported. Provide composite analysis and classify examples accordingly.

4. Lines 217–218: No references for TC genesis location or influence radius. Clarify language: “generation” implies early-stage oceanic development, likely too far from YRD to affect local O₃.

5. Lines 227–229: Claims not supported by figures. Add case studies or remove.

6. Lines 309–311: The link between TC conditions and “low humidity, strong solar radiation” is unsubstantiated. TCs often increase regional moisture. Provide observational support.

7. Line 348: The 500 hPa ridge discussion (Fig. 5g–i) is unclear. Differences between panels are not visually apparent. Consider replotting with clearer contrasts.

8. Lines 368–372: The “contribution index” needs a mathematical definition and justification. The interpretation lacks physical meaning without context.

9. Lines 393–394: Contradiction between SWP1's role here and in Table 1, where it corresponds to low O₃ levels. This undermines the credibility of classification.

10. Figure 1 caption: Missing units and variable definitions.

11. Figures 3 & 4: The presentation of SWPs is unclear. Color bars and annotations should be enhanced for readability. Distinctions among SWPs are not evident visually.

12. Materials and Methods: Define the "daily 8h average O₃" precisely, including time windows.

Review of the manuscript entitled “The impact of tropical cyclones on regional ozone pollution and its future trend in the Yangtze River Delta of China”by Mengzhu Xi et al.

General comments：

The manuscript investigates the impact of tropical cyclones on ozone and its future changing trends in the Yangtze River Delta region. Their results shows that the regional O₃ pollution are affected by tropical cyclones, and based on future scenario data, they further discuss the changes in tropical cyclones and their impact on the trend of O₃. The results are interesting for understanding the future change of tropical cyclones and O₃. Several points of the manuscript still need to be improved before accepted. Specifically, they show that the regional O₃ pollution usually occurred before and after tropical cyclones in 2018-2022 as shown in their analysis, why do they use the data reconstruction about the TC weather patterns to evaluate the annual change of O₃ concentrations in the future, instead of extreme O₃ pollution? I believe that the evaluation of extreme O₃ pollution may be reasonable. Therefore, the manuscript needs to make major revisions before their paper is considered acceptable. Please see the following comments.

Main comments：

1, As show in manuscript, the regional O₃ pollution usually occurred before and after tropical cyclones in 2018-2022 as shown in their analysis. They use the data reconstruction about the TC weather patterns to evaluate the annual change of O₃ concentrations in the future, instead of extreme O₃ pollution? I believe that the evaluation of extreme O₃ pollution may be reasonable. Please discuss this point.

2, The authors utilize the data reconstruction about the TC weather patterns to evaluate the annual change of O₃ concentrations in the future. This data reconstruction of O₃ concentrations only considers the effects of weather patterns, I want to know the effect from the perturbations in precursor emissions. Maybe the perturbations in precursor emissions can dominate the future change of O₃ concentrations. Therefore, please check the relative contributions of climate change (or weather patterns) and perturbations in precursor emissions to future O₃ concentrations.

3, In the global climate models, they can directly simulate the surface O₃ concentrations in historical and future scenarios (e.g., Turnock et al., 2020). I suggest that the authors added the results from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to further examine the Figure 9.

Turnock, S. T., Allen, R. J., Andrews, M., Bauer, S. E., Deushi, M., Emmons, L., Good, P., Horowitz, L., John, J. G., Michou, M., Nabat, P., Naik, V., Neubauer, D., O'Connor, F. M., Olivié, D., Oshima, N., Schulz, M., Sellar, A., Shim, S., Takemura, T., Tilmes, S., Tsigaridis, K., Wu, T., and Zhang, J.: Historical and future changes in air pollutants from CMIP6 models, Atmos. Chem. Phys., 20, 14547–14579, https://doi.org/10.5194/acp-20-14547-2020, 2020.