Review of “Organic amine weakens chloride depletion in coastal atmosphere” by Song et al.

In this study, Song et al. convincingly show that bases such as NH3 and amines should be accounted for in studies of chloride depletion. This is a nice message since past work on the topic is more fixated on acids and doesn’t consider the bases which can counteract the action of acids to deplete chloride from sea salt. A more specific and interesting result is that the weakening effect of dimethylamine on chloride depletion is more than that of ammonia due to stronger alkalinity and nucleation ability. Their methods are robust and based on chamber experiments; I especially appreciated that they studied the formation of corresponding organic chlorinated compounds as a result of sea salt reactions.

The topic is of interest to the journal. The presentation quality was somewhat fair with English editing work needed still. Figure quality can be improved as well. I support publication subject to the authors addressing my comments below.

Major Comments:

How significant really are these somewhat small changes in chloride depletion (20.1% to 15.8% and 18.6% to 13.5%)? Are these even significant changes, and if so, what could the implications be of these changes in the atmosphere? Please in your response build more text as well into the paper to discuss the implications of this study as right now it is unclear to readers.

Could the authors provide a brief subsection in their paper to discuss limitations of their study and potential errors/uncertainties in the context of how future work along these lines can build on these results? Also, what can observational-based studies do differently than before in light of the results of this work?

Minor Comments:

Abstract: Near the beginning the authors don’t provide any details of the methods and readers wont know how the results were obtained (e.g., is this a lab study, field work, or modeling?).

Line 147-148: hard to understand this sentence “Despite NH3 addition…”

Data Availability: This statement is somewhat weak in that data should typically be archived at a public site with a DOI number.

The manuscript presents a compelling and timely investigation into the role of alkaline species，specifically ammonia and DMA，in modulating the chemical aging of SSA. By providing the first experimental evidence that these basic gases can significantly weaken chloride depletion, the study addresses a critical gap in our understanding of the coastal atmospheric chlorine cycle. The finding that acid-base neutralization serves as a primary regulatory mechanism for reactive chlorine species production is a significant contribution that could help reconcile discrepancies between observed and modeled chloride deficits in coastal regions.

Despite its innovation, the study’s primary limitation lies in the concentration ranges employed; the use of 50–300 ppb of amines/ammonia significantly exceeds typical ambient levels (ppt to low ppb), which may exaggerate the observed inhibition effects and complicate the extrapolation to real-world conditions. Furthermore, while the study identifies organochlorines, the competitive kinetics between organic amine-acid neutralization and the oxidation of biogenic volatile organic compounds remain under-explored. Other specific comments or suggestions are as follows.