Dear authors, 

all the comments about your paper are in the attached pdf file.

General assessment:

This well-written and timely study evaluates the capacity of six widely used ozone deposition models to simulate stomatal O₃/fluxes across various global land cover types. The manuscript contributes to the Tropospheric Ozone Assessment Report (TOAR-II) community effort by assessing model behaviour under standardised conditions. It also explores both inter-model variability and sensitivity to key drivers. The study is particularly relevant for improving global ozone risk assessments and advancing vegetation impact modelling. The integration of FLUXNET and SynFlux observational constraints is commendable, and the structured multi-experiment framework is a strong point of the manuscript. That said, several aspects require clarification, particularly around the interpretation of model differences, treatment of uncertainties, and consistency in terminology and figures.

Major comments:

Clarity on Model-Observation Agreement:

The evaluation of modelled Gst against SynFlux-derived values is informative, but the conclusions could be more precise. It's difficult to assess which model(s) perform best consistently across sites. A summary table with performance metrics for each site and model would strengthen this section.

Consider providing a visual summary (e.g. radar plot or heatmap) comparing model agreement with observations across all evaluated metrics.

Treatment of Uncertainty:

While uncertainty is addressed via sensitivity experiments and ensemble medians, explicit ranges or confidence intervals for key outputs (e.g., PODy estimates) across models would be useful.

Given this variability, how robust are the conclusions regarding PODy differences across land cover types?

PODy Thresholds and Flux-Response Relationships:

The thresholds used for PODy calculation (e.g., 1 nmol m²s¹ for forests) are stated clearly, but are any species-specific or site-specific adaptations made? The text could benefit from a brief reflection on the limitations of using fixed thresholds across diverse vegetation.

Figures and Data Presentation:

Figures 3–6 are central to the conclusions, but they are visually dense due to the number of sites and models. Consider moving some detailed seasonal panels to the Supplement and simplifying the main figures.

Minor Comments:

Ensure consistent use of chemical notation: Use subscript formatting (e.g., O₃, CO₂) where possible. Standardize units throughout the text and figures (e.g., "mmol O₃ m⁻²" vs "mmol O3 m-2", "cm s⁻¹" vs "cm/s").

In multiple places, “sunlit” is referred to (e.g., Fst, sun, Gsun). Define these variables clearly in the main text, not just in figure captions or formulas.

Figures 3, 4: Increase font size in legends and axes for readability.

Figure 7–9: Consider sorting or grouping sites by land cover or latitude for more straightforward interpretation.

Table 4: Clarify whether VCmax values refer to standardised temperature conditions (25°C). Also, state if values are per sunlit leaf area or total canopy.

Avoid overly long sentences, e.g. lines 66–68, which span several embedded clauses. Break these into two sentences for readability.