Dear Dr. Wang,

Thank you very much for considering the referees' comments so carefully. I read through your point-by-point responses to the comments and suggestions from the three reviewers, and found that most of your responses would be adequate or reasonable. In the first review session, the second reviewer criticized your manuscript rather heavily in terms of new findings and some inappropriate arguments with previous studies. However, I acknowledge that you have tried to amend these properly.

So we would appreciate it very much if you could upload the latest version of your manuscript to the BG website for further review, although you kindly submitted a revised manuscript as a supplemental material to us.

Again thank you for your time to improve the manuscript.

Kind regards,

Koji Suzuki
Associate Editor

Dear Dr. Wang,

We have just received two reviews of your revised manuscript. Both reviewers were pleased to find significant improvements compared to the first version, but one out of the two referees has still some concerns such as the use of evinronmental controlling factors and ANN predictors in section 3.3 and clarification of the methodologies used in this study (see details in the file attached). Therefore, we would appreciate it very much if you could make a furhter revised manuscript with point-by-point responses to the referee's comments.

Thank you again for your nice efforts to improve the manuscript.

Kind regards,

Koji Suzuki
Associate Editor

Dear Dr. Wang,

It is a great pleasure now to accept your manuscript for publication in Biogeosciences. Thank you very much for taking into account the helpful comments from Dr. Martí Gali so carefully. Before it is published, please consider the following technical corrections.

L14: Remove “(Lana et al., 2011”) from the abstract. According to the BG manuscript preparation website (https://www.biogeosciences.net/for_authors/manuscript_preparation.html), it is mentioned that abstract should be intelligible to the general reader without reference to the text.

L24: Remove the parences for e.g. Stefels et al., 2007, that is, not (DMSP; (Stefels et al, 2007)), but (DMSP; Stifles et al., 2007).

L28 chlorophyll a (Chl a; a proxy for phytoplankton biomass). The “a” should be italic.

L 39 and hereafter: “Chl-a” is sometimes used, instead of “Chl a”. Please amend it throughout the manuscript including the figure 6 legend.

L95: fluorometric method

L111: not mg/m3, but mg m-3.

L160: The data were

L370 and hereafter: N. hemisphere? In the text, northern (or southern) is not abbreviated. Please check these throughout the text.

L399: Revolve a space immediately after “ocean”.

L476–606: For the abbreviations of journal names, please follow the Caltech Library as mentioned in the BG manuscript preparation.

https://www.library.caltech.edu/journal-title-abbreviations

Table A1: Please amend the format of References: for example, not "(Kettle et al., 1999)", but "Kettle et al. (1999)".

Again thank you for choosing the journal Biogeosciences as an outlet of your excellent work.

Sincerely,

Koji Suzuki
Associate Editor