The Different Dynamic Influences of Typhoon Kalmaegi on two Pre-existing Anticyclonic Ocean Eddy

He, Yihao; Lin, Xiayan; Han, Guoqing; Liu, Yu; Zhang, Han

doi:https://doi.org/10.5194/egusphere-2023-1734

Preprints

https://doi.org/10.5194/egusphere-2023-1734

Preprints

04 Aug 2023

| 04 Aug 2023

The Different Dynamic Influences of Typhoon Kalmaegi on two Pre-existing Anticyclonic Ocean Eddy

Yihao He, Xiayan Lin, Guoqing Han, Yu Liu, and Han Zhang

Abstract. Using multi-source observational data and GLORYS12V1 reanalysis data, we conducted a comparative analysis of different responses of two warm eddies, AE1 and AE2 in the northern South China Sea to Typhoon Kalmaegi during September 2014. The findings of our research are as follows: (1) For horizontal distribution, the area and the sea surface temperature (SST) of AE1 and AE2 decreased by about 31 % (36 %) and 0.4 °C (0.6 °C).The amplitude, Rossby number (R_o) and eddy kinetic energy (EKE) of AE1 increased by 1.3 cm, 1.4×10^-2 and 107.2 cm² s^-2 after the typhoon, respectively, while AE2 weakened and the amplitude, vorticity and EKE decreased by 3.1 cm, 1.6×10^-2 and 38.5 cm² s^-2, respectively. (2) In vertical direction, AE1 demonstrated enhanced convergence, leading to an increase in temperature and a decrease in salinity above 150 m. The response below the mixing layer depth (MLD) was particularly prominent (1.3 °C). In contrast, AE2 experienced cooling and a decrease in salinity above the MLD. Below the MLD, it exhibited a subsurface temperature drop and salinity increase due to the upwelling of cold water induced by the suction effect of the typhoon. (3) The disparity in the responses of the two warm eddies can be attributed to their different positions relative to Typhoon Kalmaegi. Warm eddy AE1, with its center located on the left side of the typhoon's path, experienced a positive work effect as the typhoon passed by. This induced a strong negative wind stress curl and triggered a negative Ekman pumping velocity (EPV), further enhanced by the converging sinking of the upper warm water, thereby strengthening AE1. On the other hand, warm eddy AE2, situated closer to the center of the typhoon, weakened due to the cold suction caused by the strong positive wind stress curl in the typhoon's center. These findings underscore the importance of relative positions of eddies in their interactions with typhoons.

Received: 27 Jul 2023 – Discussion started: 04 Aug 2023

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Journal article(s) based on this preprint

30 Apr 2024

The different dynamic influences of Typhoon Kalmaegi on two pre-existing anticyclonic ocean eddies

Yihao He, Xiayan Lin, Guoqing Han, Yu Liu, and Han Zhang

Ocean Sci., 20, 621–637, https://doi.org/10.5194/os-20-621-2024,https://doi.org/10.5194/os-20-621-2024, 2024

Short summary

Yihao He, Xiayan Lin, Guoqing Han, Yu Liu, and Han Zhang

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2023-1734', Anonymous Referee #1, 24 Aug 2023

I don’t think this paper is publishable; so sorry.
General Comments: Kalmaegi was a fast-moving TC. At 8 m/s, the TC traverses ~600 km in 1 day and spent ~6 hours traversing AE1 (or AE2) with a diameter of about 150 km. In such a super-critically moving storm, most of the wind effect on the ocean is therefore through mixing (including perhaps that caused by near-inertial internal wave breaking in the upper ocean in the wake of the storm) rather than the wind stress curl. The latter would require that wind acts on the ocean in a time scale longer than the inertial period (~1.5 days at 19N). I understand the authors' hypothesis of the negative WSC (thus convergence) on the left side, etc., but I don't think it is a demonstrable one in this case and is most likely incorrect. The increased AE1 after Kalmaegi (Fig.3, etc.) is likely a complex eddy adjustment process. One may suspect such adjustment also from Fig.3 in which the "warm" area between AE1 and AE2, including that on the left side, shrinks or weakens. That area would have expanded following the authors' hypothesis.
Two other general comments. 1) AE1’s increased amplitude, Ro and EKE = 1.3 cm, 1.4e-2 and 107 (cm/s)^2 are small. Are they statistically significant, and were errors and confidence levels estimated? Similarly for AE2. 2) Inertial oscillatory response persists long (~5 days and longer) after a storm passes (see e.g. Wu et al. Effect of Typhoon Kalmaegi (2014) on northern South China Sea explored using Muti-platform satellite and buoy observations data; Prog Oceanogr. 180 (2020) 102218). The effects of inertial motions on the Authors’ results and analyses were not discussed and I am unsure, for example, how the effects were filtered out or accounted for and how they may affect their estimates.
Other Comments:
L14: Rossby number (Ro = relative vorticity/Coriolis parameter);
L16: Rossby number;
L166: vertical feedback of the ocean by ... Kalmaegi: Not sure what this means, what "feedback", maybe "response..."?
Also: I assume GLORY assimilates Argo data but not the Station data. If so, then it is unsurprising that GLORY agrees with ARGO but not Station 5 (Figure 1).
Only Station 5 on the left side of the storm was used to support the authors' hypothesis. To support (refute?) the Authors' hypothesis I suggest using data from other Stations (except #3), right and left of Kalmaegi.
L223: ... weak wind stress curl, to be more precise. The term "wind shear" is also customarily taken as "vertical wind shear" in TC studies in meteorology so can be confusing.
L245: ... with 6-hourly dots.
.
.

Citation: https://doi.org/10.5194/egusphere-2023-1734-RC1
- AC1: 'Reply on RC1', Xiayan Lin, 30 Oct 2023
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1734/egusphere-2023-1734-AC1-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2023-1734-AC1
RC2:
'Comment on egusphere-2023-1734', Anonymous Referee #2, 08 Sep 2023
General comments:
The authors investigated the responses of two warm eddies to a typhoon using observational and reanalysis data. There have been lots of efforts on eddy feedback to TC evolution, while our understanding of eddy response to TCs remains limited. The work is potentially interesting and contribute to broaden the knowledge of TC-eddy interaction, but I have some comments before the paper can be published. I recommend moderate to minor revision of the manuscript.
Primary comments:
The motivation of conducting the study should be more clarified. Just stating that “However, there has been relatively limited exploration of different responses exhibited by warm eddies under the influence of typhoons” is not adequate from my opinion. There have been several studies on the eddy response to TCs. The authors should be more carefully summarize what have been reported from these previous studies, and what new knowledge will be reported in this study.

The writing of the paper needs a substantial improvement. There are lots of sentences that are hard to follow and hinder understanding. The logics between paragraphs should be clear. On Line 31, the word of “typhoon” is used, but in the following the “tropical cyclone” is used instead. The paper should keep consistency in word usage.

Specific comments:
1. Is it reasonable to use the rectangle areas represent AE1 and AE2 (Figure 1)? As eddies always move during typhoon.
2. There are several common issues with the figures in the manuscript that need to be addressed, including the addition of x-labels and y-labels, as well as the unification of font sizes etc. Specific comments are as follows:
1). Figure 1: The first letter of “depth” in Y-label needs to be capitalized.
2). Figure 4: Just keep one arrow legend and text of ”15 m/s” in (a), the quiver and the text should be larger.
3). The coordinate axes are duplicated in Figure 5, delete the x-axis and y-axis in Figure 5 (a), (d), (g), (j), just like Figure 4; Set the range of SST colorbar as 26 to 31 °C; Change the red dots to larger black dots.
4). Figure 6: The first letter of “date” needs to be capitalized, like “Date”.
5). Figure 7: The first letter of “date” and “depth” needs to be capitalized; The unit of “psu” should be “PSU”.
6). Figure 8: The first letter of “date” and “depth” needs to be capitalized; Please use the density excess replace the density, that means density minus 1000 kg. m^-3; The unit of buoyancy should be written as “N² (10^-4 s^-2)”.
7). Figure 9: The first letter of “depth” needs to be capitalized; “psu” should be “PSU”.
8). Figure 10: The unit of wind stress curl unit should be “N.m^-3”, so the colorbar will make some confuse, move “N.m^-3” to the right side of colorbar or another proper place.
To compare AE1 and AE2, the same figure as Figure 10 but for AE2 is needed.
9). Figure 11: The first letter of “date” and “depth” needs to be capitalized.
3. There are some spelling or inappropriate use of singular and plural in the manuscript, for example,
L39 on ‘the’ one hand
L65 the typhoon track ‘are’ more intensely
L87 of a ‘near-inertial’ wake
L118 The daily Sea Level Anomaly (SLA) and geostrophic current data ‘are’ provided by Archiving
L131 ‘database’
L156 temperature and salinity ‘from’ 1 September to 30 September 2014 ‘were’ chosen to study.
L216 ‘where’
L278 ‘passage’
L398 warm anomaly of 1.2 ℃ ‘was’ observed at a depth
L444 ‘Compared’
L508 ‘contributes’
4. Inconsistent use of tenses. When describing the work of previous researchers, you should generally use the past tense. This is because those studies have been completed in the past and form part of the background for your research. When describing your own work, you should generally use the present tense. This helps emphasize that your results are current and still valid.
For example, L122 the data access needs to use the past tense.
L309-313 please use the past tense
L316-319 please use the present tense, etc
Please check the full manuscript carefully.
5. Many abbreviations have repeated definitions, including but not limited to:
L71 and L118 SLA duplication definitions.
'EPV' is firmly defined 4-5 times, ‘Rossby number’, ‘SST’, ‘EKE’, etc.
6. A mix of American and British spellings, such as Typhoon ‘center’ and ‘centre’ are appeared in the manuscript.
7. Line 650: Please check out the format of the reference.
Citation: https://doi.org/10.5194/egusphere-2023-1734-RC2
- AC2: 'Reply on RC2', Xiayan Lin, 30 Oct 2023
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1734/egusphere-2023-1734-AC2-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2023-1734-AC2

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2023-1734', Anonymous Referee #1, 24 Aug 2023

I don’t think this paper is publishable; so sorry.
General Comments: Kalmaegi was a fast-moving TC. At 8 m/s, the TC traverses ~600 km in 1 day and spent ~6 hours traversing AE1 (or AE2) with a diameter of about 150 km. In such a super-critically moving storm, most of the wind effect on the ocean is therefore through mixing (including perhaps that caused by near-inertial internal wave breaking in the upper ocean in the wake of the storm) rather than the wind stress curl. The latter would require that wind acts on the ocean in a time scale longer than the inertial period (~1.5 days at 19N). I understand the authors' hypothesis of the negative WSC (thus convergence) on the left side, etc., but I don't think it is a demonstrable one in this case and is most likely incorrect. The increased AE1 after Kalmaegi (Fig.3, etc.) is likely a complex eddy adjustment process. One may suspect such adjustment also from Fig.3 in which the "warm" area between AE1 and AE2, including that on the left side, shrinks or weakens. That area would have expanded following the authors' hypothesis.
Two other general comments. 1) AE1’s increased amplitude, Ro and EKE = 1.3 cm, 1.4e-2 and 107 (cm/s)^2 are small. Are they statistically significant, and were errors and confidence levels estimated? Similarly for AE2. 2) Inertial oscillatory response persists long (~5 days and longer) after a storm passes (see e.g. Wu et al. Effect of Typhoon Kalmaegi (2014) on northern South China Sea explored using Muti-platform satellite and buoy observations data; Prog Oceanogr. 180 (2020) 102218). The effects of inertial motions on the Authors’ results and analyses were not discussed and I am unsure, for example, how the effects were filtered out or accounted for and how they may affect their estimates.
Other Comments:
L14: Rossby number (Ro = relative vorticity/Coriolis parameter);
L16: Rossby number;
L166: vertical feedback of the ocean by ... Kalmaegi: Not sure what this means, what "feedback", maybe "response..."?
Also: I assume GLORY assimilates Argo data but not the Station data. If so, then it is unsurprising that GLORY agrees with ARGO but not Station 5 (Figure 1).
Only Station 5 on the left side of the storm was used to support the authors' hypothesis. To support (refute?) the Authors' hypothesis I suggest using data from other Stations (except #3), right and left of Kalmaegi.
L223: ... weak wind stress curl, to be more precise. The term "wind shear" is also customarily taken as "vertical wind shear" in TC studies in meteorology so can be confusing.
L245: ... with 6-hourly dots.
.
.

Citation: https://doi.org/10.5194/egusphere-2023-1734-RC1
- AC1: 'Reply on RC1', Xiayan Lin, 30 Oct 2023
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1734/egusphere-2023-1734-AC1-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2023-1734-AC1
RC2:
'Comment on egusphere-2023-1734', Anonymous Referee #2, 08 Sep 2023
General comments:
The authors investigated the responses of two warm eddies to a typhoon using observational and reanalysis data. There have been lots of efforts on eddy feedback to TC evolution, while our understanding of eddy response to TCs remains limited. The work is potentially interesting and contribute to broaden the knowledge of TC-eddy interaction, but I have some comments before the paper can be published. I recommend moderate to minor revision of the manuscript.
Primary comments:
The motivation of conducting the study should be more clarified. Just stating that “However, there has been relatively limited exploration of different responses exhibited by warm eddies under the influence of typhoons” is not adequate from my opinion. There have been several studies on the eddy response to TCs. The authors should be more carefully summarize what have been reported from these previous studies, and what new knowledge will be reported in this study.

The writing of the paper needs a substantial improvement. There are lots of sentences that are hard to follow and hinder understanding. The logics between paragraphs should be clear. On Line 31, the word of “typhoon” is used, but in the following the “tropical cyclone” is used instead. The paper should keep consistency in word usage.

Specific comments:
1. Is it reasonable to use the rectangle areas represent AE1 and AE2 (Figure 1)? As eddies always move during typhoon.
2. There are several common issues with the figures in the manuscript that need to be addressed, including the addition of x-labels and y-labels, as well as the unification of font sizes etc. Specific comments are as follows:
1). Figure 1: The first letter of “depth” in Y-label needs to be capitalized.
2). Figure 4: Just keep one arrow legend and text of ”15 m/s” in (a), the quiver and the text should be larger.
3). The coordinate axes are duplicated in Figure 5, delete the x-axis and y-axis in Figure 5 (a), (d), (g), (j), just like Figure 4; Set the range of SST colorbar as 26 to 31 °C; Change the red dots to larger black dots.
4). Figure 6: The first letter of “date” needs to be capitalized, like “Date”.
5). Figure 7: The first letter of “date” and “depth” needs to be capitalized; The unit of “psu” should be “PSU”.
6). Figure 8: The first letter of “date” and “depth” needs to be capitalized; Please use the density excess replace the density, that means density minus 1000 kg. m^-3; The unit of buoyancy should be written as “N² (10^-4 s^-2)”.
7). Figure 9: The first letter of “depth” needs to be capitalized; “psu” should be “PSU”.
8). Figure 10: The unit of wind stress curl unit should be “N.m^-3”, so the colorbar will make some confuse, move “N.m^-3” to the right side of colorbar or another proper place.
To compare AE1 and AE2, the same figure as Figure 10 but for AE2 is needed.
9). Figure 11: The first letter of “date” and “depth” needs to be capitalized.
3. There are some spelling or inappropriate use of singular and plural in the manuscript, for example,
L39 on ‘the’ one hand
L65 the typhoon track ‘are’ more intensely
L87 of a ‘near-inertial’ wake
L118 The daily Sea Level Anomaly (SLA) and geostrophic current data ‘are’ provided by Archiving
L131 ‘database’
L156 temperature and salinity ‘from’ 1 September to 30 September 2014 ‘were’ chosen to study.
L216 ‘where’
L278 ‘passage’
L398 warm anomaly of 1.2 ℃ ‘was’ observed at a depth
L444 ‘Compared’
L508 ‘contributes’
4. Inconsistent use of tenses. When describing the work of previous researchers, you should generally use the past tense. This is because those studies have been completed in the past and form part of the background for your research. When describing your own work, you should generally use the present tense. This helps emphasize that your results are current and still valid.
For example, L122 the data access needs to use the past tense.
L309-313 please use the past tense
L316-319 please use the present tense, etc
Please check the full manuscript carefully.
5. Many abbreviations have repeated definitions, including but not limited to:
L71 and L118 SLA duplication definitions.
'EPV' is firmly defined 4-5 times, ‘Rossby number’, ‘SST’, ‘EKE’, etc.
6. A mix of American and British spellings, such as Typhoon ‘center’ and ‘centre’ are appeared in the manuscript.
7. Line 650: Please check out the format of the reference.
Citation: https://doi.org/10.5194/egusphere-2023-1734-RC2
- AC2: 'Reply on RC2', Xiayan Lin, 30 Oct 2023
  
  The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1734/egusphere-2023-1734-AC2-supplement.pdf
  
  Citation: https://doi.org/10.5194/egusphere-2023-1734-AC2

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Xiayan Lin on behalf of the Authors (30 Oct 2023) Author's response Author's tracked changes

EF by Sarah Buchmann (02 Nov 2023) Manuscript

ED: Referee Nomination & Report Request started (06 Nov 2023) by Anne Marie Treguier

RR by Anonymous Referee #2 (16 Nov 2023)

RR by Anonymous Referee #3 (20 Dec 2023)

RR by Anonymous Referee #4 (21 Dec 2023)

ED: Reconsider after major revisions (21 Dec 2023) by Anne Marie Treguier

AR by Xiayan Lin on behalf of the Authors (22 Jan 2024) Author's response Author's tracked changes Manuscript

ED: Reconsider after major revisions (23 Jan 2024) by Anne Marie Treguier

Dear Dr Lin,

I am really sorry, but the remarks of one of the reviewers were not entered properly into the system. As a result, you could not see them, you could only see the first short paragraph.

I apologize for this problem and for the delay it will cause you in the revision of your manuscript. I copy the review below. Could you take it into account and resubmit?

Yours sincerely,

Anne Marie Treguier

Review of: The Different Dynamic Influences of Typhoon Kalmaegi on two Pre-existing Anticyclonic Ocean Eddy
Author(s): Yihao He et al.

I am not sure about the novelty of the results presented here. The aim of the paper is not presented clearly. As a consequence, it is difficult for the reader can see the value of the manuscript in the context of an already very rich literature on the subject. The manuscript requires a major revision.

An important issue is that the response made to reviewer 1 does not seem adequate.
Reviewer#1 criticizes your interpretation: he says that because the typhoon is moving too fast for the wind stress curl to have a direct influence, all the influence of the typhoon should occur through vertical mixing driven by near-inertial waves, which is different in anticyclones compared with cyclones (see for example Jaimes et al 2011, Journal of Physical Oceanography). If I read correctly your answer to the reviewer, you claim that the wind stress changes, so the Ekman depth changes: but the Ekman depth is a measure of how deep the mixing is, not a measure of the geostrophic response to the wind stress curl. The standard (textbook) definition of the Ekman depth depends on the vertical mixing coefficient and the Coriolis frequency, it does not depend on the wind stress nor on the wind stress curl. Therefore you do not answer the reviewer question. An interesting reference to answer reviewer#1 could be Lu et al (JGR, 2023), who demonstrate the influence of the wind stress curl on the eddies. Or, perhaps, you could make an answer based on Jaimes and Shay (2015), because those authors study the response of warm eddies to a hurricane, just like you do; note that they point out that it is not the hurricane wind stress curl ("undisturbed" Ekman pumping) which is important but rather the "nonlinear" Ekman pumping (second term in their equation 5). You would need to estimate parameters similar to the ones of Lu et al, or Jaimes and Shay, for the specific case of your warm eddies and your typhoon Kalmaegi, to be able to argue that either of these interpretations applies to your case.

The introduction could be improved. The literature review is too long and not very easy to read. The lines 96 to 98 are not enough to motivate the paper: reading this sentence, it seems that you just want to add two more eddies to the already rich literature on eddy-cyclone interactions, without asking specific scientific questions, nor pointing out why your study is really original and important.

In the introduction you don't justify at all why you consider typhoon Kalmaegi. How special is this typhoon, relative to other TCs in the area? In the response to the reviewers you mention that Zhang has published 6 other papers about this typhoon and the observations made in 2014, but this is not highlighted in the introduction. You need to explain better why the present paper is different from the work that has already been published, what is new here. Are the observations you show already published elsewhere? If it is the case, why is another paper warranted?

line 417 and following: The discussion is very descriptive and does not discuss what is new in your results compared with the literature. The typhoon has a different effect on the two eddies. Is this just what one would expect based on the different positions of the eddies relative to the typhoon track, based on the existing literature? Or is there a bit of surprise in your observations? The way the manuscript is written, without first laying out hypothesis and more precise scientific questions, it is difficult for the reader to understand whether you just confirm existing theories with additional observations (which is worthy in itself), or whether there is something new (which is more exciting). When you say "The negative wind stress curl induced by the typhoon resulted in favourable surface ocean currents that further enhanced the clockwise rotation of the warm eddy": are you sure this sentence is valid in view of the high translation speed of the typhoon (reviewer#1's remark?)

The summary just repeats the main elements of the discussion (different response of the two eddies) but it lacks perspectives.

A few detailed remarks:

Lines 54 to 57: I don't understand this sentence. It does not seem to be grammatically correct.
line 59: "In general, TCs strengthen cold eddies": this statement seems in contradiction with Sun et al 2014, who say "only about 10% of COEs were significantly influenced by these super typhoons". It would be more appropriate to say "In some cases" " rather than "in general".
line 73: "reduction of warm eddies": to you mean a reduction in numbers (less eddies)? Or do you mean a weakening of each eddy?
line 96: "previous studies focused on the interaction of cold cyclonic eddies and TCs: is it true than warm eddies have been overlooked? You refer to many publications about the interaction with warm eddies (lines 73 to 95), how do you assess that the warm eddies have not been focused on? The second part of that sentence is not clear. What are you investigating? The effect of the typhoon on an eddy is not a "feedback", is it?

lines 171-173: this is an example of badly constructed sentences. There are many problems with grammar in the manuscript.

Figure 2a is not informative at all. If Glorys assimilated the ARGO data at that time and location, the comparison is not a validation of the product. I suppose that Glorys did not assimilate the data from the buoys? Then Figure 2b shows a real validation with independant data. It would be better to show profiles at different buoy locations only, and not an ARGO profile, in Figure 2.

lines 195 to 199, EKE definition: you need to say relative to what (time mean? spatial mean?) the anomaly is computed. Also, you should say how you compute the Ekman depth.

Hide

AR by Xiayan Lin on behalf of the Authors (23 Jan 2024) Author's response Author's tracked changes Manuscript

ED: Reconsider after major revisions (24 Jan 2024) by Anne Marie Treguier

Dear Yihao He,

I apologize again for the problem that prevented you from receiving the 3rd review in its integrality.
Following our email exchange, I return the manuscript to you, so you can take this extra review fully into account.
I paste again the missing review in this message, in case.

Yours sincerely,

Anne Marie Treguier

Review of: The Different Dynamic Influences of Typhoon Kalmaegi on two Pre-existing Anticyclonic Ocean Eddy
Author(s): Yihao He et al.

I am not sure about the novelty of the results presented here. The aim of the paper is not presented clearly. As a consequence, it is difficult for the reader can see the value of the manuscript in the context of an already very rich literature on the subject. The manuscript requires a major revision.

An important issue is that the response made to reviewer 1 does not seem adequate.
Reviewer#1 criticizes your interpretation: he says that because the typhoon is moving too fast for the wind stress curl to have a direct influence, all the influence of the typhoon should occur through vertical mixing driven by near-inertial waves, which is different in anticyclones compared with cyclones (see for example Jaimes et al 2011, Journal of Physical Oceanography). If I read correctly your answer to the reviewer, you claim that the wind stress changes, so the Ekman depth changes: but the Ekman depth is a measure of how deep the mixing is, not a measure of the geostrophic response to the wind stress curl. The standard (textbook) definition of the Ekman depth depends on the vertical mixing coefficient and the Coriolis frequency, it does not depend on the wind stress nor on the wind stress curl. Therefore you do not answer the reviewer question. An interesting reference to answer reviewer#1 could be Lu et al (JGR, 2023), who demonstrate the influence of the wind stress curl on the eddies. Or, perhaps, you could make an answer based on Jaimes and Shay (2015), because those authors study the response of warm eddies to a hurricane, just like you do; note that they point out that it is not the hurricane wind stress curl ("undisturbed" Ekman pumping) which is important but rather the "nonlinear" Ekman pumping (second term in their equation 5). You would need to estimate parameters similar to the ones of Lu et al, or Jaimes and Shay, for the specific case of your warm eddies and your typhoon Kalmaegi, to be able to argue that either of these interpretations applies to your case.

The introduction could be improved. The literature review is too long and not very easy to read. The lines 96 to 98 are not enough to motivate the paper: reading this sentence, it seems that you just want to add two more eddies to the already rich literature on eddy-cyclone interactions, without asking specific scientific questions, nor pointing out why your study is really original and important.

In the introduction you don't justify at all why you consider typhoon Kalmaegi. How special is this typhoon, relative to other TCs in the area? In the response to the reviewers you mention that Zhang has published 6 other papers about this typhoon and the observations made in 2014, but this is not highlighted in the introduction. You need to explain better why the present paper is different from the work that has already been published, what is new here. Are the observations you show already published elsewhere? If it is the case, why is another paper warranted?

line 417 and following: The discussion is very descriptive and does not discuss what is new in your results compared with the literature. The typhoon has a different effect on the two eddies. Is this just what one would expect based on the different positions of the eddies relative to the typhoon track, based on the existing literature? Or is there a bit of surprise in your observations? The way the manuscript is written, without first laying out hypothesis and more precise scientific questions, it is difficult for the reader to understand whether you just confirm existing theories with additional observations (which is worthy in itself), or whether there is something new (which is more exciting). When you say "The negative wind stress curl induced by the typhoon resulted in favourable surface ocean currents that further enhanced the clockwise rotation of the warm eddy": are you sure this sentence is valid in view of the high translation speed of the typhoon (reviewer#1's remark?)

The summary just repeats the main elements of the discussion (different response of the two eddies) but it lacks perspectives.

A few detailed remarks:

Lines 54 to 57: I don't understand this sentence. It does not seem to be grammatically correct.
line 59: "In general, TCs strengthen cold eddies": this statement seems in contradiction with Sun et al 2014, who say "only about 10% of COEs were significantly influenced by these super typhoons". It would be more appropriate to say "In some cases" " rather than "in general".
line 73: "reduction of warm eddies": to you mean a reduction in numbers (less eddies)? Or do you mean a weakening of each eddy?
line 96: "previous studies focused on the interaction of cold cyclonic eddies and TCs: is it true than warm eddies have been overlooked? You refer to many publications about the interaction with warm eddies (lines 73 to 95), how do you assess that the warm eddies have not been focused on? The second part of that sentence is not clear. What are you investigating? The effect of the typhoon on an eddy is not a "feedback", is it?

lines 171-173: this is an example of badly constructed sentences. There are many problems with grammar in the manuscript.

Figure 2a is not informative at all. If Glorys assimilated the ARGO data at that time and location, the comparison is not a validation of the product. I suppose that Glorys did not assimilate the data from the buoys? Then Figure 2b shows a real validation with independant data. It would be better to show profiles at different buoy locations only, and not an ARGO profile, in Figure 2.

lines 195 to 199, EKE definition: you need to say relative to what (time mean? spatial mean?) the anomaly is computed. Also, you should say how you compute the Ekman depth.

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AR by Xiayan Lin on behalf of the Authors (27 Jan 2024) Author's response Author's tracked changes Manuscript

ED: Reconsider after major revisions (01 Feb 2024) by Anne Marie Treguier

AR by Xiayan Lin on behalf of the Authors (23 Feb 2024) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (26 Feb 2024) by Anne Marie Treguier

RR by Anonymous Referee #3 (04 Mar 2024)

RR by Anonymous Referee #2 (08 Mar 2024)

ED: Publish subject to technical corrections (17 Mar 2024) by Anne Marie Treguier

Dear Dr He,

The reviewers are now satisfied with the revised version of your manuscript, congratulations for your thorough revision work.
Some grammar errors remain, but I hope that these technical problems can be fixed during the publication stage (see below).

Yours sincerely,

Anne Marie Treguier

Abstract:
- The use of tenses is not uniform. If you choose the present tense, say "A2 (...) Rossby number and EKE decrease", not decreased.
- AE2 weakens

line 260 " increases by 1.3 cm"
lines 260, 263: You say "area of the AE1" but "core of AE2": the use of "the" should be the same everywhere. You should remove "the" before the anticyclone names AE1 and AE2.
line 326: "persistence"
line 445 "using"
line 447 "the vertical velocity... are presented": either the velocity is presented, or the velocities are presented.
line 460: instead of "warm core of the eddy AE1" just say "warm core of AE1".
line 464: "the downwelling of warm eddy" is not grammatically correct. You could "enhances the downwelling and inputs negative vorticity in AE1".
line 503: rather say "within AE2".
line 515: "locates" and "strengthens with amplitude" do not seem good style. You could say "AE1 is located outside (...). Its amplitude, Ro and EKE strengthen after the passage of the Typhoon. "
line 516 "weakens with amplitude, Ro and EKE" is not a good style. You could perhaps just say "weakens"?
line 527: I would suggest "AE1, located outside the Rmax of the typhoon, is subjected to a negative wind stress curl which generates a potential vorticity perturbation inside the eddy. " (It seems obvious you are talking about the typhoon, do you need to repeat typhoon three times?)
line 529: "is enhanced"
line 530 "within AE1"
line 535 "respond differently to the typhoon".
line 536-537: If you use "while", you cannot stop the sentence at the end of line 537. A grammatically correct sentence could be "while..., conversely...). However, long sentences should be avoided: I think the best would be to remove "while" in line 536.
line 538: "Conversely...." this sentence says exactly the same thing as the previous one: it should be removed to avoid repetition.
line 542: "This is discussed for the first time".
line 546: "and enhance"

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AR by Xiayan Lin on behalf of the Authors (20 Mar 2024) Author's response Manuscript

Journal article(s) based on this preprint

30 Apr 2024

The different dynamic influences of Typhoon Kalmaegi on two pre-existing anticyclonic ocean eddies

Yihao He, Xiayan Lin, Guoqing Han, Yu Liu, and Han Zhang

Ocean Sci., 20, 621–637, https://doi.org/10.5194/os-20-621-2024,https://doi.org/10.5194/os-20-621-2024, 2024

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Yihao He, Xiayan Lin, Guoqing Han, Yu Liu, and Han Zhang

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By utilizing multi-source observational data and GLORYS12V1 reanalysis data, we investigate the different responses of two warm eddies to typhoon Kalmaegi. Both AE1 and AE2 decrease in area and surface temperature during the typhoon, but other parameter exhibit opposite behaviors in AE1 and AE2. They also have different vertical structures. These differences attributed to their different positions, resulting in downwelling pumping in AE1 and upwelling suction in AE2.

The Different Dynamic Influences of Typhoon Kalmaegi on two Pre-existing Anticyclonic Ocean Eddy

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