Review of the Manuscript "Influence of Planetary Boundary Layer Dynamics on New Particle Formation in Cyprus" by Neha Deot.

This manuscript investigates the role of planetary boundary layer (PBL) dynamics in shaping new particle formation (NPF) processes in Cyprus, providing valuable regional data that could fill an existing gap in the literature. While the study highlights an important atmospheric phenomenon, there are several areas where the work could benefit from greater depth and clarity.

Major Comments.

Depth and Novelty of the current Research 

The research focuses on a critical aspect of atmospheric science, but the novelty of the study is not articulated strongly enough. A few points to consider:

•    How does this study advance the understanding of PBL-NPF interactions compared to prior research in regions like Finland, France, or South China etc.?

•    What unique atmospheric conditions or challenges in the Eastern Mediterranean make this work distinct? For instance, could the region’s combination of desert dust, marine air masses, and urban pollution add complexity to the PBL-NPF relationship?

Interpretation of Results

The data presented is intriguing, but several aspects warrant deeper analysis and more comprehensive discussion, for example:

1.    The study observes concurrent NPF events between the two sites only ~50% of the time. Why might this be the case? Could localized meteorological conditions, chemical heterogeneity, or even differences in precursor availability explain these findings?

2.    The 1–2 hour lag in particle detection attributed to vertical mixing and up-valley winds is plausible but needs stronger support. Would a modeling exercise or sensitivity analysis help validate this mechanism?

3.    Why are particle growth rates not compared systematically between sites to explore environmental or chemical factors impacting aerosol growth?

The authors could probably expand the discussion to include alternative mechanisms for site-to-site discrepancies, support transport and mixing hypotheses with additional data or quantitative modeling and maybe Include particle growth rate comparisons to add depth to the environmental impact analysis.

Uncertainties and Limitations

The AMX site is assumed to always reflect PBL conditions, but is this assumption realistic? How might deviations affect the study’s conclusions? Missing data from instruments like the NAIS is mentioned but not explored. How significant are these gaps in terms of bias or statistical robustness? If this is possible, please, add a subsection explicitly addressing uncertainties, including the potential impact of AMX site assumptions and data gaps. Also, use confidence intervals, error bars, or sensitivity analyses to quantify the reliability of key findings.

 Broader Implications 

The study briefly mentions the relevance of NPF to climate models but does not expand on how these findings contribute to global or regional policy and scientific efforts. For example, how do the results improve our understanding of aerosol-cloud-climate interactions in climate change hotspots like the Eastern Mediterranean? 

Are there any size distribution measurements available, such as from an SMPS? Including this data, if available, could significantly strengthen your results and enrich the content of your article.

Minor Comments

•    How do these results compare to studies in other regions with distinct PBL dynamics, such as monsoonal areas, polar regions, or highly urbanized environments?

•    Are there notable agreements or contradictions with global patterns that could deepen the scientific understanding of PBL-NPF processes?

•    Some figure captions need to be fixed. For example, in Figure 5, the caption's references to 'a)', 'b)', and 'c)' do not align with the correct sequence of the figures.

•    Figure 3. (c) and (d) should be in the right order. Also, for (c) and (d) the months on the x-axis are not visible.

•    Could key findings, such as size-segregated particle concentrations or particle growth rates, be summarized in supplementary tables to enhance accessibility for readers?

•    Line 226. Delete the “----"