Dear Editor,

Enclosed herewith please find the responses to the comments raised by Referee 1 about the manuscript currently entitled: "​A 4D-Var Data Assimilation System for the North-Western Mediterranean Sea and its Impact on the Corsica Channel Transport", referenced as n°2025-3806.

We thank the Referee for her/his thorough reading of the text and useful comments. Attached is our detailed response  while modifications to the manuscript are highlighted using quotation marks in the response.

Following the suggestion of one of the Referees we have revised the title of the manuscript that now is entitled “Impact of Assimilated Observations on the Corsica Channel Transport in a 4D-Var System for the Northwestern Mediterranean Sea”.

We would like to emphasize that several comments from the Referees pointed toward a more detailed process-oriented study. While we addressed these comments as much as possible, we would like to clarify that the primary objective of this manuscript is to present and evaluate the Data Assimilation tool, while  maintaining the focus on a key region for the northwestern Mediterranean Sea, namely the Corsica Channel. A more in-depth investigation of the regional physical processes in the northwestern Mediterranean, using Data Assimilation as an investigative framework, is an important and complementary effort. This work is currently ongoing and will be presented in a dedicated future manuscript.

We hope that we have addressed satisfactorily all the points raised by Referee 1.

Best Regards,

On behalf of all authors Michele Bendoni

Dear Editor,

Enclosed herewith please find the responses to the comments raised by Referee 2 about the manuscript currently entitled: "​A 4D-Var Data Assimilation System for the North-Western Mediterranean Sea and its Impact on the Corsica Channel Transport", referenced as n°2025-3806.

We thank the Referee for her/his thorough reading of the text and useful comments. Attached is our detailed response  while modifications to the manuscript are highlighted using quotation marks in the response.

Following the suggestion of one of the Referees we have revised the title of the manuscript that now is entitled “Impact of Assimilated Observations on the Corsica Channel Transport in a 4D-Var System for the Northwestern Mediterranean Sea”.

We would like to emphasize that several comments from the Referees pointed toward a more detailed process-oriented study. While we addressed these comments as much as possible, we would like to clarify that the primary objective of this manuscript is to present and evaluate the Data Assimilation tool, while  maintaining the focus on a key region for the northwestern Mediterranean Sea, namely the Corsica Channel. A more in-depth investigation of the regional physical processes in the northwestern Mediterranean, using Data Assimilation as an investigative framework, is an important and complementary effort. This work is currently ongoing and will be presented in a dedicated future manuscript.

We hope that we have addressed satisfactorily all the points raised by Referee 2.

Best Regards,

On behalf of all authors Michele Bendoni