Dear Yuewei Guo and Yunge Zhao,
Meanwhile, we obtained three reviews of your manuscript with valuable comments and you already responded to all of them. In a next step, can you please prepare a revised version of your manuscript, where all the issues addressed by the reviewers are thoroughly addressed. Please also provide a response letter with your final response to all issues.

Thank you very much and kind regards,

Bettina Weber

Dear Yuewei Guo and Yunge Zhao,

thank you very much for submitting the second version of your manuscript, where you treated most of the referee's comments in an adequate manner. Nevertheless, there are still quite some language issues, as e.g. in the description of the results in the abstract (page 1, line 20ff.) but also throughout the text, which hamper the comprehensibility of the manuscript. Thus, can you please ask a native speaker or someone speaking English fluently to thoroughly check and improve the language of your manuscript.

Thank you very much and kind regards,

Bettina Weber

Dear Yuewei Guo and Yunge Zhao,

The readibility of your manscript has improved significantly during the last review process! It now is ready for publication in Biogeosciences.

Kind regards,

Bettina Weber