Review of «A New Vision of the Adriatic Dense Water Future under Extreme Warming» by Denamiel et al.

The authors investigated the future evolution of dense and deep water formation in the Adriatic Sea, as well as its further spread and accumulation at different locations in the sub-basin, following the pseudo global warming (PGW) approach under the RCP8.5 emissions scenario. For this purpose, the authors use kilometer-scale simulations performed with the Adriatic Sea and Coast (AdriSC) climate model. The AdriSC model has already been evaluated in previous work. By the end of the century, the authors find a NaddW formation similar to the present climate, while the AdDW formation is expected to decrease. The authors report some new findings that make the article very interesting. Indeed, the evolution and mechanism of deep water formation is a central topic in oceanography, especially in the Mediterranean Sea. Its future changes could have implications for regional circulation, biogeochemistry and marine ecosystems. In my opinion, the main novelty of this work is that the authors have examined the future effects on the dynamics of the NaddW and the AdDW separately, thanks to the use of kilometer-scale simulations.

The manuscript is generally well written and organized, and the results are relevant to the scientific community, especially the Mediterranean community. However, I found some points that should be improved before its publication in OS.

1) Throughout the manuscript, the authors compare their results with those previously obtained by Parras-Berrocal et al. (2023) using a future projection performed with one of the coupled regional models participating in the Med-CORDEX initiative. However, I also miss a discussion with the results obtained by Soto-Navarro et al. (2020), who analyzed the future evolution of deep water formation in the Adriatic Sea with an ensemble of fully coupled regional climate models from the Med-CORDEX. In this study, some models predict a decrease in deep water formation in the Adriatic, while others predict an increase. My advice is to try to position AdriSC within the Med-CORDEX ensemble. Does AdriSC project an average or an extreme behaviour with respect to the rest of the model simulations? The results in Soto-Navarro et al. 2020 (Table 8 and Figure S19) should help you to reinforce this point in the introduction and in the discussion.

2) Regarding Figure 1, what criteria do you use to define the 5 subdomains (coloured polygons)? It should be stated somewhere in the text. Perhaps you could change the colour of the DKB polygon as it is quite similar to the colour used in NA. Could you include the meaning of MSL in the caption? The acronym MSL is not defined anywhere in the text.

3) One of my main concerns is that throughout the manuscript the authors give values for the differences between the RCP85 and historical periods. However, in most cases these differences are not easy to visualise in the figures because the authors show the historical and RCP8.5 periods separately. I strongly recommend that Figures 6, 7, 10, 11, 12 be redesigned to include a third column with the differences, or that both periods be combined in one column and the differences added in a second column. This would make the manuscript easier to follow.

4) Lines 333-336: What about the possibility of including a new subdomain located offshore NA and KB sites in the analysis?

5) In Figure 13, the SI appears to be calculated for the DJFM period. This is strange if the aim is to estimate the resistance of the water column to convection. Please consider computing it for a period before convection (for example in December or in autumn).

6) Please add letters to the figure panels at least in Figures 14 and 15. This will make the text easier to read and understand. Captions should be rewritten accordingly.

7) Figure 16 is not easy to understand on its own. I would recommend following the numerical order used in the conclusions section to reorganize the figure, giving the same number to the processes involved in each conclusion. Otherwise, I would recommend removing Figure 16.

Minor remarks:

- L44: include density value of densest water based on previous literature.

- L60: Regional Climate Model (RCM) → Regional Climate System Model (RCSM)

- Section 2.1.2: Could you indicate the length of the spin-up?

- In Figure 2, as well as in 3, 13, 14, I would recommend using Depth instead of Height.

- L117: Please include a reference to the definition of extreme Bora events (i.e. gale-force winds).

- L144: I would suggest replacing the term Dense Water Height (DWH) with isopycnal depth.

- In Figure 3, could you use the same colorbar range in both top panels? Another option is to include a sentence in the caption stating that different colorbar ranges are used to better visualize the figures.

- Line 153: “… summarized with box plots (Figure 13)..”

- Figure 4: I would suggest including the vector field.

- Lines 212-217: This paragraph is hard to follow. In the text, the horizontal wind transport ranges from 20 to 2800 × 10⁹ m³/s, while in Figure 6 it ranges from 0 to 8 [10⁹ m³/s]. Please clarify the order of magnitude used.

- Line 312: In terms of the Naddw transports (Figure 12). Sometimes in the text the authors do not refer to the figure they are talking about. Please check the whole manuscript.

- Line 327: In Parras-Berrocal et al. (2013), the authors consider NaddW and AdDW as Adriatic Deep Water without distinction due to the coarse resolution of the RCSM used.

- L345-346: “ (i.e., shift in peak reduction in dense water transports between T3 and T4; Fig. 12)” I do not fully understand what the authors

- Line 351: 29.09 kg/m³ → 28.4 kg/m³?

- Line 371: Modified Atlantic Water → Atlantic Water

References of this review not already cited by the authors:

Soto-Navarro, J., Jordá, G., Amores, A., Cabos, W., Somot, S., Se- vault, F., Macias, D., Djurdjevic, V., Sannino, G., Li, L., and Sein, D.: Evolution of Mediterranean Sea water properties un- der climate change scenarios in the Med-CORDEX ensemble, Clim. Dynam., 54, 2135–2165, https://doi.org/10.1007/s00382-019-05105-4, 2020.

Review of the paper

A New Vision of the Adriatic Dense Water Future under Extreme Warming

Author(s): Clea Lumina Denamiel et al.

MS No.:   egusphere-2024-2524

MS type:   Research article

A kilometer-scale atmosphere-ocean model is used to assess the impact of a far-future extreme warming scenario on the formation, spreading and accumulation of the dense water in the Adriatic Sea.

The text is well written and results are presented clearly. I recommend minor corrections:

Specific comments:

105 : Please better explain the PGW approach and its consequences on the model behavior, as it is a key point for the paper.

455 : The choice of the boundary conditions and its implication on the exchange at the southern border are not well described. Could authors further discuss this point.