Dear Authors, editor, and reviewers,

This manuscript presents insights into the interactions between sea spray aerosols (SSAs) and aromatic acids through a laboratory study. This is an interesting and valuable research. I have some constructive comments on this manuscript.

Specific comments:

Abstract and Introduction:

Line 11, what is the importance of aromatic acids with SSAs in affecting the global radiative balance? In the following section of Introduction (Lines 29-40), the authors had ambiguous presentation in relationship between SSAs, aromatic acids, and global radiative balance.

Lines 41-54: The authors introduced the current studies in seawater source of aromatic acids in this paragraph, that is, the majority is from esters released and biodegraded by algae and the remain is from anthropogenic emissions. Could aromatic acids be derived from precipitation? What are the major types and their proportions and concentrations of aromatic acids in seawater? It should correspond to aromatic acids the authors used in the experiments (lines 90-98, 2 Experiment Section). More detailed description and possible summary are needed.

Line 80 Sintered glass filter and wave breaking method can also produce artificial SSAs with different properties of flux, chemical composition, size distribution, and so on. The authors should clarify the relationship between methods (sintered glass filter, plunging jet, and wave breaking) and possible efficiency of aromatic acid transport within SSAs. That is, whether the plunging jet method can effectively reflect the “Role of sea spray aerosol at the air-sea interface in transporting aromatic acids to the atmosphere”?

Experimental Section

Lines 90-97 Why do authors chose these types of aromatic acids? It should be clarified.

Lines 93-94 The collection procedure of seawater is not clear (site, chemical composition of seawater, contamination control, storge conditions, filtration or not?) Detailed QA/QC description is needed.

Line 98: What is the mass concentration of typical aromatic acids in true seawater, which determines whether the concentration of aromatic acid used in the experiment (1 mM) is reasonable.

Line 135 Can this flow rate of 1 mL min^-1 for 1 h collect particles? If so, possible sampling artifacts should be considered. I think this flow rate is too small and cannot achieve/tune with DKL-2.

Results and discussion

Section 3.2.2 and Fig. 4

How quantitatively determine the thickness of organic coating of collected individual particles and what is the basis of the order? Can thickness of organic coating of selected individual particles represent the whole populations? Is there a statistic bias using only one typical TEM image?

Section 3.3

How many samples were used to calculate the enrichment factors of aromatic acids and cations (both in Figures 5 and 6)? It should be summarized as a new table. The authors performed size-resolved filter-based experiments, what is the level of enrichment factors of aromatic acids in different size?

The authors hypothesize that the binding effect of Ca²⁺ with aromatic acid is a reason for observed positive enrichment of aromatic acids. In fact, the positive calcium enrichment is also observed using artificial seawater without organic matters (Salter et al., 2016). Therefore, this hypothesis may need additional control experiments, for example, using pure NaCl solution with addition of aromatic acids, to excluded the effect of Ca²⁺.

Lines 313-326 I found a missing detail in authors evaluate the cation enrichments, that is, the detailed mass concentration ratio of cations to Na⁺, for example of Ca²⁺/Na⁺, in both seawater and aerosol samples is missing. I therefore suggest the authors supplement more details in mass concentration ratio of aromatic acids and cations in seawater and aerosol samples as a new table.

Minor comments:

Lines 57: Please clarify “a potential route”.

Lines 59-62: This sentence is hard to follow. What is that sea-salt included organic surfactants can thereby further disturbing ecological systems? The cited references also seem inappropriate.

Line 109 What is the air flow rate? It should be different in different experiment procedures.

Fig.3 It is hard to follow the differences in particle size, because these circles are almost identical.

Fig.4 It is hard to follow the colors of subplots A, B, and C. The color span between groups should be larger.

Reference

Salter, M. E., Hamacher-Barth, E., Leck, C., Werner, J., Johnson, C. M., Riipinen, I., Nilsson, E. D., and Zieger, P.: Calcium enrichment in sea spray aerosol particles, Geophys Res Lett, 43, 8277-8285, https://doi.org/10.1002/2016gl070275, 2016.