Dear authors,
Thank you for your responses to the reviewers. I woud like now to invite you to prepare a revised version of the manuscript, which should take into account all the issues raised by the referees. In particular, the revised version should be more detailed in the description of the methods and the experiments conducted, as well as provide a tighter and more coherent relationship between introduction, objectives and discussion. The revised version will be sent for additional review to at least one of the original referees.
Thank you for submitting your work to Biogeosciences.
Sincerely,
Emilio Marañón

Dear authors,

Your manuscript still needs additional work. The description of the sampling programme, and experiments conducted, needs to be clearer. The uncertainties in the approach must also be acknowledged more explicitly, and some of the conclusions should be presented in a more nuanced way.

I have written several editorial comments (attached) that hopefully should be helpful in preparing a new version of the manuscript. I note that there are many typos in the text, particularly in the new passages. The new version should be prepared more carefully.

Best regards,

Emilio Marañón

Dear authors,
Thank you for your responses to my previous editorial comments. Although the methodological aspects of the manuscript are now clearer, there are still a few issues that require attention. In particular, the legend to Figure 9 must be revised. Plase consider the attached comments.
Best regards,
Emilio Marañón