Analysis of Mesoscale Eddy Merging in the Subtropical Northwest Pacific Using Satellite Remote Sensing Data
Round 1
Reviewer 1 Report
Review comments on Analysis of Mesoscale Eddy Merging in the Ocean Using Satellite Remote Sensing Data by Fu et al. submitted to Remote Sensing.
This is a well-written paper. It should be published after some minor revisions. Below are my comments and suggestions.
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Ln 195, the definition of R already described in the previous paragraph
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Ln 211-213, It is unclear the definition of pre-merging sum and how the increase is calculated. The pre-merging process is a dynamic stage that changes over time. Do you compare the average of stage 3 to the average of stage 1? Cannot see the increase in amplitude and radius from Figure 5. Same questions for the increase during Phase 3 for the sum of A1 and A2 (Ln 244-246).
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Figure 5 and 9, would it make more sense to show the average Amplitude in (a) instead of the sum of C1 and C2 during phase 1. In (b), I understand radius is proportional to area. Would it be more straightforward to show the area? What is the physical meaning of the sum of radius? Should the radius of C1 +C2 be calculated as sqrt[(S1+S2) /pi] where S1 (S2) is the area of C1 (C2)?
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It’s interesting to see the influence of merging in SST change. I wonder how this impacts biological activities. It might be worthwhile to investigate if the ocean color (chlorophyll a) changes during the same merging events and broaden the impacts of this study.
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Understanding the single merging event is useful, but it might be more valuable to investigate how often the eddy merging happened in the ocean. Some statistics of frequency, types, duration etc. of eddy merging in the ocean (even in a selected region) will make the paper more interesting and valuable.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors use satellite altimetry data to demonstrate the eddy merging and its impact on SST in the subtropical NW Pacific in September - November 2008 and May 2012. I suggest the authors to improve the MS following the below comments:
1. Please add “Study area” subsection to Data and Methods section. Add brief description of the eddies in the study area (water structure, mechanisms of formation). It’s necessarily to mention that the study area (Kuroshio Extension region) is one of the regions with the highest eddy kinetic energy (Wyrtki et al., 1976) and characterized by high eddy variability as observed by satellite altimetry (e.g. Qiu and Chen. Variability of the Kuroshio Extension …and mesoscale eddies. J. Phys.Ocean. 2005).
2. The title of MS should be corrected to indicate the study area (subtropical NW Pacific).
3. Please mention about the history of analyzed eddies. As a reader, you may want to see a more details (the eddy origin and pathways).
4. The subtropical NW Pacific is the Rossby wave pathway (32- 40N). SLA/SSH maps clearly demonstrate the Rossby wave in the study area in spring/summer 2012. Where the Rossby wave impacted (or not) the eddies in the study area in September – November 2008 and May 2012?
5. Discussion (L. 243-263). Out of the vertical distribution of temperature the discussion of eddy merging impact on satellite SST (< 1-2 mm layer) looks too speculative. Please, add and discuss the vertical profiles of temperature/density in study area in May and October (Supl. Mat.). You can use the Argo buoys (captured by eddies) data. Also, JMA (Japan Meteorological Agency) shipborne data (transection along 137E) is available for public (JMA website).
Please, note that the spring/summer (fall/winter) warming (cooling) could lead to higher (lower) SST inside of the eddies than in the surrounding water (due to limited horizonal advection and mixing). It’s exactly what you get.
6. L. 48- 49. “…the precise merging process of eddies …and exact merging process of …eddies..”. The text should be revised.
7. Conclusion. L. 300-303. The authors present only two events of the eddy merging. It’s not enough for “..systematic analysis of the merging processes of cyclonic and anticyclonic eddies..”.
8. L. 131. The text should be corrected.
Minor revision
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
