Dear Dr Loscher

Thank you very much for responding to reviewer comments. Please submit a revised manuscript for consideration.

Regards,

Clare Woulds

Dear Dr Loscher

Thank you for the revised version of your manuscript. I find that you have answered most reviewer comments thoroughly. However, I feel that more needs to be done in response to the first comment by reviewer 1 regarding proper acknowledgement of the depths from which N2 fixation rate and other measurements are available throughout the manuscript.

Firstly, please make sure that your sampling depths are stated in the methods section in much more detail (i.e. give the depth range over which each set of measurements was made). If necessary please add a table to the methods section showing sampling depths. Currently the depths are only available by looking at the supplementary material, which is not acceptable.

Secondly, during the results section please specify what depth range is meant by ‘surface waters’ and other non quantitative terms, and re-state the depth of the DCM.

Thirdly, please add a short paragraph early in the discussion to answer the reviewer’s point, and to justify why the data that you have, over the depth range that you have, are a sufficient basis for the conclusions you have reached.

Please also add further detail to the S1 caption, or provide additional text, to indicate how different groups of phytoplankton were derived from the satellite data.

Many thanks, and I look forward to receiving a new draft of your manuscript.

Yours sincerely,

Clare Woulds

Dear Dr Loscher

Thank you for submitting a revised version of your manuscript. I am now very happy to recommend publication in Biogeosciences.

Best wishes for 2020,

Clare Woulds