Dear authors,
thank you for the detailed responses to the referees' comments. Please include in your revised MS or in the supplementary material, all the additional information necessary to deal with these comments, as stated in your answers.
looking forward to reading the new version of this interesting work
best regards
Gwenaël Abril
BG associate Editor

Final decision BG 503

Dear authors

I will be pleased to accept your paper for publication after you have considered the following minors comments. Please re-submit a revised version of your MS together with an explanation on how you have dealt with these comments.
Looking forward reading the final version of your MS.
Best regards
Gwenaël Abril

You have chosen the “result and discussion” structure for your paper
Chapter numbers and title must follow this format.
In addition, I believe your paper be easier to read if you combine actual 3.1+3.3 and 3.2+3.4, without altering the text.

Actual:
3. Results
3.1 CH4 fluxes
3.2 CO2 fluxes
3.3 Implied seawater CH4 concentrations and saturations from fluxes
3.4 Implied seawater CO2 concentrations and saturations from fluxes
4 Spatial variability in seawater concentrations
4.1 Variability in salinity
4.2 Variability in seawater pCO2
5 Estimation of the CO2 gas transfer velocity
5.1 Dependence of KCO2,660 on wind speed
5.2 Dependence of KCO2,660 on friction velocity
5.3 Seasonal variability in KCO2,660
5.4 Dependence of KCO2,660 on bottom-driven turbulence
6. Effects of rain on air-sea CO2 exchange
6.1 Effect of rain on K
6.2 Dilution effect on near-surface pCO2
7 Conclusions

Please consider the following proposition:
3. Results and discussion
3.1. CH4 and CO2 fluxes and implied seawater concentrations
3.1.1. CH4
3.1.2. CO2
3.2. Spatial variability in seawater concentrations
3.2.1. Variability in salinity
3.2.2. Variability in seawater pCO2
3.3. CO2 gas transfer velocity
3.3.1. Dependence of KCO2,660 on wind speed
3.3.2. Dependence of KCO2,660 on friction velocity
3.3.3. etc…
3.3.4.
3.4. Effects of rain on air-sea CO2 exchange
3.4.1. Effect of rain on K
3.4.2. Dilution effect on near-surface pCO2
4. Conclusions


Other comments on the text :
L39 : change “terrestrial aquatic systems” to “continental aquatic systems” or “inland aquatic systems”

L50 “Due to both the ‘solubility pump’ and the ‘biological pump’, the surface ocean can be a net source or sink of CO2, depending on location and time of the year” The term “pump” clearly applies for the case of a sink of atmospheric CO2, but not for a source. Please rephrase

L52“The global open ocean is modelled to absorb”, not sure this is the appropriate formulation

L83 not sure if mentioning such details on surfactants effect on K is relevant in the introduction of the present study, which does not deal with surfactants.