Dear Matthew,

two experts have now reviewed your manuscript. Both reviewer's agree that your data set is interesting and does add to the literature on hydrology as a driver of pond (bio)geochemistry but both reviewers also voice substantial concern with respect to the presentation and interpretation of your data in the MS. I fully agree with them. In particular, the interpretation of hydrochemistry lacks more hydrological data, and needs some work on the terminology. Furthermore, it seems necessary to address stratification more thoroughly and to consider as to how much the ponds studied are representative.

With considerations of your replies, I believe that the reviewers concerns can be addressed appropriately and, after major revisions, I would welcome a new MS for further consideration.

With the best wishes, Helge

Dear Matthew,

the two reviewers seem relatively satisfied with your response and the revised version. Yet, both still raise a number of concerns that I agree with, and which I'd thus like to ask you to revise accordingly. Most importantly, reviewer 1 points out that the ponds you investigated were rather shallow and that it is therefore not surprising that rainfall events will modify the composition of solutes. The question that thus arises is: how representative are your study sites. This should be integrated in your MS to make the reader aware of the potential limitations of this study.

Furthermore, the quality of figures/tables still needs considerable (!) improvement:
Generally: use a common font type/size. Fig 3 is composed of two columns, Fig 4 of one but the font of axis labels etc is not uniform at al! Some figures are very rough (Excel?) exports in low resolution (eg Fig 4 labels are almost not discernible) and font type/size used for eg axis labels is differential across different figs. Scale figures sensibly. Do Fig 1 or 2 (for example) really need 1 page in width (I doubt it)?

Tab. 1: the horizontal lines are much, much too thick. Please check with a previously published BG article and with our format guidelines.
Tab 2: even worse, the horizontal and vertical lines are double lines. Make this single and less, less thick (see above).
Tab3 and 4: see tab 1 and 2 criticism.
Fig. 1: There’re several issues with this figure. The insert map indicates two things which I cannot really relate to the bigger map: there is a star (Churchill region) but it is unclear if the small area you investigated (the big map has ~10 km stretch of coastline at the Hudson bay) is within this Churchill area (the star has a diameter of perhaps 100 km. Is the aforesaid area that big?). Then it’s very unclear what the dark region, which is basically the entire coastline of Ontario at the Hudson Bay signifies. Finally, the big map needs an x-axis (longitude) and y-axis (latitude). Without this, the figure is not acceptable because it lacks reference.
Fig 6. the colour scaling of the PCA does not make sense like this as it is only possible to lets say discern day 200 from 150 but not 200 from 250.

Please make sure to address all criticism and concern raised by the reviewers and myself.

With the best wishes, Helge

Dear Mathew,

thank you very much for the last edits on this work.

Best, Helge