In this paper, the authors use a standalone terrestrial biosphere model to evaluate both multiplicative and photosynthesis-based schemes of stomatal conductance of ozone. Observational datasets of the dry deposition velocity and the stomatal conductance of ozone are used to do the model evaluation. The authors suggested that the photosynthesis-based stomatal algorithms that captured the responses to water stress had a better agreement with the observations. The manuscript describes a straightforward modeling study exploring basic parameterizations and comparisons to observations, and fits into the scope of Biogeosciences. I have a few minor comments as listed below.

My major concern is that based on the model-observation comparison in this paper, I do not see a significant improvement by using photosynthesis-based stomatal conductance methods, compared to the traditional multiplicative methods. The default multiplicative W89 scheme without stomatal response to water stress fails to reproduce the diurnal variations in Gs, but the multiplicative Z03 method seems to agree well with the other photosynthesis-based methods and the observations. Furthermore, all schemes compare poorly with observations in rainforests and in the Blodgett forest site (which is often associated with higher temperatures and water stress). Can the authors comment a bit more on the advantages of using photosynthesis-based methods?

The numbers and names of the modeling schemes are sometimes confusing. For example, the words “multiplicative” and “photosynthesis-based” in the title refer to stomatal conductance schemes, not dry deposition schemes, right? In the abstract, the Medlyn scheme is also a photosynthesis-based method, so there are actually two multiplicative (W89, Z03), two photosynthesis-based (FBB, MED) stomatal conductance schemes. I think it should be stated clearly in the abstract and introduction, or it will confuse the readers.

Also, the figures should be consistent to show all 6 schemes when comparing to observed dry deposition velocity Vd, and show all 4 schemes when comparing to observed stomatal conductance Gs. For example, why not compare the Z03 scheme in Figure 11?

L42: Does this “45%” refer to an annually averaged percentage? How does this compare to your results? As the stomatal conductance is the main focus of this paper, I would suggest moving Figure S3 (showing the fraction of stomatal conductance to total deposition) to the main text.

L257: Please briefly explain the P-M method here.

Table 3: This table contains a lot information and is not easy to read. How about using some background colors, e.g., red/blue to show overestimation/underestimation and dark/light colors to indicate large/small bias?

L327 Not sure what this sentence means. Do you mean ozone reacts “with” soil-emitted NO and BVOC here?

Figure 2 The models seem to predict an overall earlier peak than the observations. Can the authors comment on why it could be?

L401 which site is “ponderosa pine forest”? Include the site name here.

Finally, this manuscript includes many abbreviations and sometimes is hard to follow. I would suggest including a list of abbreviations and explanations if possible.

The authors examine the impact of carrying the stomatal conductance parameterization on the predicted deposition velocity. Comparisons are made between the well-used Wesely (1989) and Zhang et al. (2003) approaches as well as derivative parameterizations developed by substituting two different photosynthesis-based approaches into both the Wesely and Zhang approaches.  Results are compared against observational data from several flux studies as well as the SynFlux dataset.  Overall, the paper is sound but could benefit from additional editing.  The text in Table 3 is very small as is the text in Figure 1.  I am surprised that the photosynthetic models did not offer greater improvements in modeled values and would be interested in your thoughts on that.  I would also be interested in seeing values of the correlation coefficient.

Technical comments:

Line 111: It would be helpful to include examples of the biosphere-atmosphere interactions that are lacking in CTMs

Lines 140-143: There are multiple implementations of the W89 and the Z03 schemes in CTMs.  Please be more specific here as to which implementation you used for both frameworks and not any specific differences that would have implications to the results here.

Line 170: Not specific to this line of text per se, but little is said about the stomatal blocking factor that is in the Z03 scheme and the potential effect of it.  While it doesn’t affect the actual value of the stomatal resistance, it definitely has implications for the contribution of that pathway to the overall canopy resistance and the deposition velocity.  It merits a bit of attention in the paper.

Lines 220-226: It has previously been stated that the W89 version is the one in GEOS-Chem and it doesn’t need to be restated here.  The focus here is clearly on the stomatal parameterization.  Have other papers already addressed the non-stomatal resistances?  Perhaps cite any studies that have here and maybe make recommendations about whether that work should or could be part of future work.

Lines 227-228, it would be helpful to add “in TEMIR” after mode for clarity or you could add text to the model description to indicate that it runs both in single-site mode and as a gridded model.

Lines 239-240: It would be helpful here to indicate how the model handles multiple land use types within the grid cell.  Again, this could be added here or in the model description.  It is stated a bit later but would be better addressed in Section 2.1. The grid cell size is pretty large for ecosystem specific studies.  What impacts might that have?

Line 265: It would be helpful to provide the Penman-Monteith method in the Supplemental.

Line 292-292:  I don’t agree with the statement that the schemes can generally capture the magnitude for the major PFTs.  The models do not capture the range of values observed for the coniferous forest or the rainforest and predict a range of values for grasses that is larger than the observations.

Line 305:  How did you determine that the modeled vd for grasses is largely determined by the minimum stomatal resistance?

Line 469:  It might be helpful here to add a few sentences comparing these results to the ones for the field study sites.

Line 535-536: It isn’t clear to me where in Figure 9a, the non-stomatal vs stomatal deposition rates are provided.

Line 385: Define RuBP; also is equation 8 also from Franks et al.?

Figure 11: Why is W89 only used in this figure rather than including Z03?

Line 622-623: The results are not very convincing for switching to a photosynthesis-based model

Line 637: I am a curious about the use of “guaranteed” here.

Line 648:  While I fundamentally agree that photosynthesis-based models offer opportunities for improving our estimates of air-surface exchange, I think there is still a lot to be considered when coupling in grid models with subgrid variability in vegetation types.

Editing notes:

Lines 27 – 29: Sentence could benefit from editing

Line 89: Consider rewording to “tree and crop species of concern”

Line 90: Add “the” before DOSE

Line 127-128: Change “discussed” to “discuss”; add “the” before stomatal; parameterization should be plural

Line 157: add “the” before dry

Line 179: change its to their

Line 194: change “is” to are

Equation 4: the concentration should be denoted by C not c

Line 213: add the before photosynthetic

Line 277: Insert “the” before different and dry

Figure 1: in the caption, add “where” before different.  I would also suggest using different colors as the current ones may not be optimal for users with color blindness issues.

Line 352: add “mean: after monthly

Line 360: delete “in this”

Line 377: Perhaps the second vd in the sentence should be Gs?

Line 604:  I have seen those experiments referred to as FACE not FREE