In this work the authors analyse the impact of different methodologies, namely the reference baseline method, in the MHW detection and characteristics in the Balearic Sea. This is a topic under open discussion among the MHW research community. The authors conclude that the choice of the detection method is crucial depending on the research intended objectives, but that’s not a novelty as some recent studies have already underlined. The manuscript is worth publishing but needs some improvement, outlined below.

The introduction section should more in detail discuss studies on Mediterranean MHWs, that have very recently received growing interest in scientific literature, as the manuscript refers to a Mediterranean subregion. Recent papers discuss the consideration of spatial requirements for MHWs, build MHW catalogues or MHW drivers.

The authors use appropriate methodology to assess those impacts and properly discuss them. But the last part of section 4.4 (from line 285) looks on definition impacts in biodiversity more like as a review of the state-of-the-art of MHW biological impacts. These section needs to be, in part, rewritten to better highlight the authors results.

Minor comments

Line 40: Please correct “in studies in studies”

Line 47: Please correct “underlaying”

Line 65: Change “air-sea heat fluxes and producing a decrease” to “air-sea heat fluxes and produce a decrease”

2.4 Marine heat waves metrics

The category list and table 1 are unnecessary as they are well described in the Hobday references. Please consider adding the necessary definitions in a new paragraph.

This article focuses on the Balearic Sea, a critical sub-region of the western Mediterranean, highlighting its ecological importance and the increased risk of species loss due to climate change. The main objective of the study is to assess trends in sea surface temperatures (SST) and marine heatwaves (MHWs) obtained by different methods, using 42 years of SST satellite observations (1982-2023).

Although the study is well written and makes a valuable contribution to the field, it needs some major concerns to increase its clarity and overall impact. These improvements are described in detail below:

Major comments:

-  The authors follow the definition of MHW by Hobday et al. (2016). In several places in the manuscript, it is mentioned that Hobday et al. (2016) proposed to calculate the MHW climatology based on SST from 1982 to 2001. This is not accurate, as they suggested using an SST for at least 30 years to derive climatological baselines. In this paper, they used the years 1982 to 2011 to calculate the MHWs of 2003, 2011 and 2012, which was quite appropriate. In addition, there are several studies that have followed Hobday et al. (2016) and used 30 or more years of climatology in the Mediterranean and different regional seas. They have avoided reaching saturation (year-round MHWs) by using the appropriate baseline for their study period and at the same time their work met the criteria suggested by Hobday et al. (2016). Some of these articles are ([1–7]).

This comment should definitely be taken into account as it changes the results, especially in the part of the comparison between the different methods, and could also mean changes in the conclusion.

-  The introduction would benefit from a more detailed discussion of recent studies on MHWs in the Mediterranean region. As the MS focuses on a sub-region of the Mediterranean, it would be good to have a comparison with the other Mediterranean regions from the literature ([1,3,4]).

Minor notes:

Figures and tables:

-  Table 1: Consider removing this table or replacing it with a short paragraph in the text.

-  Figure 2, panel (b): I recommend removing this panel and keeping only panel (a and c). If the authors have a good reason to keep panel (b), I suggest replacing the term "residuals" of SST with "deseasonalized" SST, since the term "residuals" is typically associated with sea level data that include tidal and residual components.

- Figure 3 and 4: Could the author add the grid on the figures and add the tick on the x-axis of panel (a) of the figures.

- Figure 5: For clarity, use a different color scheme in panel (a) that better differentiates between high and low values.

- Figures 6 and 7: The same suggestions apply as for Figure 5.

Abstract:

- In the abstract, please indicate the time period used to calculate the SST trends before mentioning the results of it.

Data and methods:

-  Line 96: as previously mentioned Hobday et. al (2016) suggested using 30 for the climatology baseline calculations and for their study they used data from 1982 to 2011, please correct this here and everywhere else in the MS.

Results:

-  Figures 3 and 4: It is quite interesting that the year 2022 shows an increase in MHW characteristics for the three MHW detection methods, especially for the method that uses detrended data. Does this mean that the strong occurrence of MHW in 2022 was not primarily caused by global SST trends. Did the authors try to identify the reasons for this interesting result?

- There is an error in the numbering of the headings. There is section 2 and then section 4, please correct this.

Suggested References:

1. Hamdeno M., Alvera-Azcaráte A. // Front. Mar. Sci. 2023. v. 10. p. 1093760.https://www.frontiersin.org/articles/10.3389/fmars.2023.1093760/full. (Accessed June 10, 2023)
2. Hamdeno M., Alvera-Azcárate A., Krokos G., Hoteit I. Marine Heatwaves in the Red Sea and their Relationship to Different Climate Modes: A Case Study of the 2010 Events in the Northern Red Sea // Remote Sensing/Climate and modes of variability. 2024 (Accessed February 8, 2024).https://egusphere.copernicus.org/preprints/2024/egusphere-2024-355/. (Accessed February 8, 2024)
3. Ibrahim O., Mohamed B., Nagy H. // JMSE. 2021. V. 9. № 6. P. 643.https://www.mdpi.com/2077-1312/9/6/643. (Accessed June 14, 2021)
4. Galli G., Solidoro C., Lovato T. // Front. Mar. Sci. 2017. v. 4. p. 136.http://journal.frontiersin.org/article/10.3389/fmars.2017.00136/full. (Accessed June 15, 2021)
5. Mohamed B., Nilsen F., Skogseth R. // Frontiers in Marine Science. 2022. V. 9. .https://www.frontiersin.org/article/10.3389/fmars.2022.821646. (Accessed June 12, 2022)
6. Mohamed B., Ibrahim O., Nagy H. // Remote Sensing. 2022. V. 14. № 10. P. 2383.https://www.mdpi.com/2072-4292/14/10/2383. (Accessed May 27, 2022)
7. Mohamed B., Barth A., Alvera-Azcárate A. // Front. Mar. Sci. 2023. V. 10. .https://www.frontiersin.org/articles/10.3389/fmars.2023.1258117. (Accessed June 14, 2024)