Challenges in modeling spatiotemporally varying phytoplankton blooms in the  Northwestern Arabian Sea and Gulf of Oman

Sedigh Marvasti, S.; Gnanadesikan, A.; Bidokhti, A. A.; Dunne, J. P.; Ghader, S.

doi:https://doi.org/10.5194/bg-13-1049-2016

Articles | Volume 13, issue 4

https://doi.org/10.5194/bg-13-1049-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/bg-13-1049-2016

© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 13, issue 4

Research article

|

23 Feb 2016

Research article |

| 23 Feb 2016

Challenges in modeling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

S. Sedigh Marvasti, A. Gnanadesikan, A. A. Bidokhti, J. P. Dunne, and S. Ghader

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Final revised paper (published on 23 Feb 2016)
Preprint (discussion started on 01 Jul 2015)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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RC C3913: 'RC', Anonymous Referee #1, 29 Jul 2015
RC C4281: 'Review of "Challenges in modelling spatio-temporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman" by Sedigh Marvasti et al.', Anonymous Referee #2, 13 Aug 2015
- AC C4820: 'Response to interactive comments (Referee 2) on “Challenges in modelling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman” by S. Sedigh Marvasti et al.', Seyedehsafoura Sedigh Marvasti, 28 Aug 2015
AC C4450: 'Response to: Interactive comment on “Challenges in modeling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman” by S. Sedigh Marvasti et al.', Seyedehsafoura Sedigh Marvasti, 19 Aug 2015

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (09 Oct 2015) by Laurent Bopp

AR by Seyedehsafoura Sedigh Marvasti on behalf of the Authors (17 Nov 2015) Author's response Manuscript

ED: Referee Nomination & Report Request started (07 Dec 2015) by Laurent Bopp

RR by Anonymous Referee #2 (21 Dec 2015)

Suggestions for revision or reasons for rejection

The manuscript has improved considerably since the previous version. In particular, the Introduction, Discussion and Figures have become much clearer and more informative. I recommend publication after minor revisions.

Having said that, I still think that the question why the Fall bloom is larger than the Spring bloom should be investigated in more detail. From the new Figure 7, it seems pretty clear that the large Fall bloom is due to a large Summer maximum in nutrient concentrations and that the smaller Spring bloom is due to a relatively small Winter maximum in the nutrient concentrations. But now the question becomes: why don't the models reproduce the large Summer nutrient maximum and the small Winter nutrient maximum? The explanation given in thye manuscript that "this is probably associated with the models mixing to excessive depth during the wintertime" (page 14, line 408/409) is very dissatisfactory. It may not be feasible to include a deeper analysis in this manuscript, but the authors could at least provide a discussion how the origin of the asymmetry in the observed nutrient dynamics may be investigated in further studies.

Technical corrections:

p. 4, l. 114: Resplandy et al. (2011) indicted that the spatial -> Resplandy et al. (2011) indicated that the spatial
p. 4, l. 122: with the specification four -> with the specification of four
p. 10, l. 286: macronutrient tracer Behrenfeld (2010). -> macronutrient tracer (Behrenfeld, 2010).
p. 10, l. 307: Within the smalle region the values are -> Within the small region, the values are
p. 18, l. 530: much water from Persian Gulf -> much water from the Persian Gulf
p. 20, l. 590: blooms in during certain times -> blooms during certain times
p. 20, l. 617/618: However, for a few cases eddies with a bloom -> However, for a few cases, eddies with a bloom
p. 20, l. 618/619: In this region consistency is observed -> In this region, consistency is observed

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ED: Publish subject to minor revisions (Editor review) (06 Jan 2016) by Laurent Bopp

Dear Safoura Sedigh Marvasti,
First, I’d like to thank you for the thorough revision of your manuscript. Based on my own reading, and on the re-review of one of the initial referee, I can say that you manuscript has considerably improved and reads much better. The introduction and discussion sections in particular are much clearer and much more informative now.
Overall, I’m satisfied with the way you responded to most of the comments. I would be happy to accept your manuscript in BG, but subject to minor revisions.
The last major concern raised by the referee relates to the mechanisms behind the asymmetry between the winter and summer blooms, and the fact that this is not reproduced by the model. I would encourage you to strengthen (1) the analysis and /or (2) the discussion on potential on how the mis-represented nutrient dynamics may be explored in a subsequent study.
The manuscript also needs some careful re-reading to correct a few spelling mistakes. Technical technical corrections noted by the referee are:
p. 4, l. 114: Resplandy et al. (2011) indicted that the spatial -> Resplandy et al. (2011) indicated that the spatial
p. 4, l. 122: with the specification four -> with the specification of four
p. 10, l. 286: macronutrient tracer Behrenfeld (2010). -> macronutrient tracer (Behrenfeld, 2010).
p. 10, l. 307: Within the smalle region the values are -> Within the small region, the values are
p. 18, l. 530: much water from Persian Gulf -> much water from the Persian Gulf
p. 20, l. 590: blooms in during certain times -> blooms during certain times
p. 20, l. 617/618: However, for a few cases eddies with a bloom -> However, for a few cases, eddies with a bloom
p. 20, l. 618/619: In this region consistency is observed -> In this region, consistency is observed

I hope you’ll be able to take these comments on board. Again, thanks for submitting your best work to Biogeoscienes,
Sincerely yours,
Laurent Bopp

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AR by Seyedehsafoura Sedigh Marvasti on behalf of the Authors (13 Jan 2016) Author's response Manuscript

ED: Publish as is (01 Feb 2016) by Laurent Bopp

Short summary

This study examines challenges in modeling phytoplankton blooms in Northwestern Arabian Sea and Gulf of Oman. Blooms in the region show strong modulation both by seasons and in the wintertime by eddies. However getting both of these correct is a challenge in a set of state-of-the-art global Earth System models. It is argued that maintaining a sharp pycnocline may be the key for preventing the wintertime bloom from being too strong and for allowing eddies to modulate upward mixing of nutrients.