Mesoscale Eddies in the Black Sea and Their Impact on River Plumes: Numerical Modeling and Satellite Observations

Round 1

Reviewer 1 Report

This paper is using DieCAST model and satellite data to study the Mesoscale Eddies in the Black Sea was impacted by river.The paper is good quality, the only one comment need to work  before publication in remote sensing.

In the paper, author use the Lagrangian particle tracking model to study the water properties (temperature, salinity, velocity and density), however the temperature and salinity behavior is different to the particle motion. This part need to be modified. 

Author Response

Answers to comments and suggestions by Review#1

This paper is using DieCAST model and satellite data to study the Mesoscale Eddies in the Black Sea was impacted by river. The paper is good quality, the only one comment need to work before publication in remote sensing.

In the paper, author use the Lagrangian particle tracking model to study the water properties (temperature, salinity, velocity and density), however the temperature and salinity behavior is different to the particle motion. This part need to be modified.

- Yes, we agree with the last remarks. Behavior of river particles does differ from ambient water parcels; that is why our Lagrangian model was, generally, designed with algorithms governing properties of particle, as was described in [3]. In the present work, we used simplified version limited by with passive particles to avoid effects associated with particle transport due to thermohaline mechanisms.

We should recall that our study aims the genesis of topographically generating mesoscale eddies and their effect on spreading river water along the Caucasian coast. As the first step, using dynamically passive particles allowed us to understand mechanisms of particle leakages from the eddy and propagating particles (representing river waters) from the coastal zone to the open sea. The next step is planning to include the algorithms describing properties of dynamically active particles.

Reviewer 2 Report

The authors using numerical modeling and satellite observations to study the mesoscale eddies in the Black Sea, the work make contributions to the material transporting of mesoscale eddies, but the language still needs to be polished as a lot of mistakes are included. The following are some comments:

 

1. Line 119, ‘northeastern’ should be changed to ‘Northeastern’.

2. Figure 1, The authors put the numbers of bathymetry in the figure, it is not very clear, use a colorbar instead will make it better

3. Line 151, what are the resolution of the physical boundary conditions, initial conditions, and surface forcing?

4. Line 167, 6 mins, not 6 min. Please check all language mistakes.

5. Line 184, the authors mentioned altimetry data, but what kind of satellite altimetry data are used? The resolution and time span?

6. Figure 2, what are the red lines?

7. Figure 5, the colorbar of sea surface height is strange during 0-5 cm, what is the white bar? Check all colorbars please.

Comments for author File: Comments.pdf

Author Response

Answers to comments and suggestions by Review#2

Thank you for the useful comments and suggestions that helped to improve the MS

“... the language still needs to be polished as a lot of mistakes are included.”

We agree with this remark and the entire text was polished up essentially.

Here are the answers to the remarks: (the answers in Italic)

1. Line 119, ‘northeastern’ should be changed to ‘Northeastern’.: -
2. Figure 1, The authors put the numbers of bathymetry in the figure, it is not very clear, use a colorbar instead will make it better. - We added the colorbar for bathymetry and tuned palette to make all depth levels to be pronounced.
3. Line 151, what are the resolution of the physical boundary conditions, initial conditions, and surface forcing? – All features of the model were described in Section 2.2. Here, we recall that modeling was performed for the entire Black Sea but discussed results were given only for the Caucasian Coast as shown in Figure 1.
4. Line 167, 6 mins, not 6 min. Corrected.

Please check all language mistakes. Sorry, we were in a hurry to meet the deadline and many bugs left. We made double check of the text and fix all mistakes and misspellings found.  The entire text was "polished up".

5. Line 184, the authors mentioned altimetry data, but what kind of satellite altimetry data are used? The resolution and time span? - For validation of the model we used results of utilization of TOPEX/Poseidon and ERS-I, II (TP-E) altimeter data. In particular, to track of displacement of mesoscale eddies along the Caucasian Coast and changes of their temporal and spatial scales, we used the results of altimeter data processed in [23]. Combined TP and ERS allowed improving resolution no SSH up to 2cm.Horizontal effective resolution is 0.25 Deg. In case of combination of  TP-E, the spatial resolution increases up to ~10 km. Time span was  used to be 7 years but processed period was from May 1992 to May 1999. In [28], on the base of TP-E results, obtained in [23], we studied processes of the protrusion of near-coastal anticyclonic eddies through the Rim Current in the Black Sea and got reasonable results.
6. Figure 2, what are the red lines? Explanation was added in the caption of Figure 2
7. Figure 5, the colorbar of sea surface height is strange during 0-5 cm, what is the white bar? Check all colorbars please. – the colorbar of SSH was corrected to adjust for both panels of Figure 5.

Reviewer 3 Report

This paper emphasized the importance of river runoff in the formation of medium-scale eddies along the RC and tried to verify the simulation results through satellite observation. Authors are encouraged to submit this article to 'Ocean Modeling'. Although "mesoscale eddy" is on the keyword list and this article focuses on "mesoscale eddy", this article does not include anything new in observing ocean currents from a satellite's perspective. Also, it is hard to admit the importance of river discharge on the dynamics of mesoscale eddies without a comparison between the simulations with and without river discharge. 

Author Response

Answers to comments and suggestions by Review#3

Thank you for the useful comments and suggestions.

Below authors' answers are written in italic

This paper emphasized the importance of river runoff in the formation of medium-scale eddies along the RC and tried to verify the simulation results through satellite observation. Authors are encouraged to submit this article to 'Ocean Modeling'. 

- Thank you for this suggestion, actually, for 'Ocean Modeling', we intend to prepare a paper focused on processes of interaction of brackish waters with eddy structures.

Although "mesoscale eddy" is on the keyword list and this article focuses on "mesoscale eddy", this article does not include anything new in observing ocean currents from a satellite's perspective.

– We agree with this remark. "mesoscale eddy" was input the keyword as “topographically generated mesoscale eddies”

Also, it is hard to admit the importance of river discharge on the dynamics of mesoscale eddies without a comparison between the simulations with and without river discharge.

- Good question! We agree with this remark but note that the prsent work aimed to study the effect of a powerful topographic eddy progressing along the Caucasian coast on numerous river discharges and an assessment of the eddy effect on the water exchange between the coastal zone and open sea that is evidenced by satellite imagery. Further detais on interrelation between eddy structure and riverine water discahge with be studied in coming papers. 

 

Round 2

Reviewer 3 Report

My concerns were all addressed in the author's replies, and I have no objection to its publication.