Synoptic and Dynamic Analyses of an Intense Mediterranean Cyclone: A Case Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, the author seeks to examine the synoptic conditions that contributed to the explosive cyclogenesis associated with a Mediterranean cyclone on February 3rd, 2006. Much of the analysis of this paper is based upon the detailed available kinetic energy (AKE) budget analysis using reanalysis data associated with this event, and it was shown that AKE generation was primarily driven by the evolution of the polar and subtropical jet activity. This was a well-written manuscript, and I believe that the author has shown the clear connection between jet stream activity and explosive cyclogenesis in this study. I believe that this paper is suitable for publication if the author addresses some concerns regarding the methodology and the results. My full comments (including some grammatical corrections) are attached, but the most important comments are given below:

(1) Within the methodology section, the author uses temperature advection as a diagnostic. With regards to temperature advection, the author doesn't mention what levels will be assessed (i.e. 925 hPa, 850 hPa, etc.). Also, since temperature advection could vary between adjacent layers, it would seem more appropriate to use layer-averaged temperature advection (such as 925-850-hPa thermal advection). Furthermore, since there will be sinking and rising motion associated with the cyclone, why did the author choose not to use potential temperature advection.

(2) Following the previous point, relative vorticity is used as a diagnostic for this study. However, within the methodology section, the author doesn't mention what levels at which relative vorticity will be addressed. Furthermore, since the extratropical cyclone in this study is associated with the upper-tropospheric troughs and ridges, it would be useful to include vorticity advection as a diagnostic (especially since vorticity tendency is related to cyclogenesis).

(3) At some points, the AKE analysis obscures some dynamical points that are relevant.

• For example, since jet stream dynamics strongly dictates the cyclone in this study, it would be expected that there would be significant ageostrophic flow associated with the jet stream, which should produce enhanced upper-troposphere divergence and convergence (depending upon the location of the jet stream to the surface cyclone center).
• Furthermore, as the author notes in lines 506 - 513, there is a clear coupling between the surface cyclone and the upper-tropospheric vorticity patterns. This is to be expected because boundary layer pumping and upper-troposphere divergence affect the sea-level pressure tendency and the vorticity tendency. This coupling should also be influence the interaction between the surface fronts associated with the cyclone and the upper-tropospheric troughs.

It would be useful if the author shows how the AKE analysis extends and/or support our current dynamical understanding of the relationship between fronts, jets, and cyclones.

(4) In the abstract and within the Section 3.1, the author acknowledges that diabatic processes also play a role in evolution of the cyclone, but this point is not developed in the paper. Previous research has shown that the period of most rapid deepening for a midlatitude cyclone occurs when heavy precipitation develops poleward and westward of
the cyclone center. This is due to the fact that the associated latent heat release from cloud condensation can (1) add energy to the system, (2) focus and intensify the vertical motion pattern by reducing the static stability, and (3) produce a positive feedback between sensible and latent heat fluxes and cyclogenesis. This is known as the self-development paradigm, and the distribution of precipitation matches Figures 5-6. It would be useful if the author provides additional detail on how the presence of clouds and precipitation affect the dynamical evolution of the cyclone.

Comments for author File: Comments.pdf

Author Response

The corrections required by – Reviewer 1

Journal:                       Climate

Manuscript Number: climate-3611555

Paper Title:                 Synoptic and Dynamic Analysis of an Intense  Mediterranean Cyclone: A Case Study
Type:                            Article

Author:                      Ahmad E. Samman

           

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In this manuscript, the author seeks to examine the synoptic conditions that contributed to the explosive cyclogenesis associated with a Mediterranean cyclone on February 3rd, 2006. Much of the analysis of this paper is based upon the detailed available kinetic energy (AKE) budget analysis using reanalysis data associated with this event, and it was shown that AKE generation was primarily driven by the evolution of the polar and subtropical jet activity. This was a well-written manuscript, and I believe that the author has shown the clear connection between jet stream activity and explosive cyclogenesis in this study. I believe that this paper is suitable for publication if the author addresses some concerns regarding the methodology and the results. My full comments (including some grammatical corrections) are attached, but the most important comments are given below:

 Many thanks to the reviewer for his interest in reviewing the research with high accuracy and for all the scientific comments he recommended that helped raise the level of this work.

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(1) Within the methodology section, the author uses temperature advection as a diagnostic. With regards to temperature advection, the author doesn't mention what levels will be assessed (i.e. 925 hPa, 850 hPa, etc.). Also, since temperature advection could vary between adjacent layers, it would seem more appropriate to use layer-averaged temperature advection (such as 925-850-hPa thermal advection). Furthermore, since there will be sinking and rising motion associated with the cyclone, why did the author choose not to use potential temperature advection.

• I am grateful for the reviewer's insightful comments regarding the temperature advection analysis.
• This study's temperature advection analysis primarily focused on the 850 hPa level, a common practice in synoptic meteorology for diagnosing low-level thermal advection influencing cyclogenesis and weather patterns. This level is widely recognized for its utility in identifying significant thermal advection patterns that contribute to cyclonic development, frontal intensity, and precipitation types. It is typically prioritized because it effectively represents thermal advection near the boundary layer while generally lying above the planetary boundary layer, thus reducing diurnal surface effects and avoiding surface interference. The choice of 850 hPa also aligns with modern cyclone studies (Martineau et al. 2024; Al-Mutairi et al. 2023), which demonstrate its diagnostic value for capturing the thermal structure of developing baroclinic systems and its ability to provide sufficient spatial coverage above the Earth's surface while still representing near-surface processes. Although temperature advection was also calculated at the 1000 hPa and 925 hPa levels (below figures), the general pattern was found to be nearly identical, with no significant differences observed between 850 hPa and 925 hPa as illustrated in the figures below. Consequently, the analysis presented in this study focuses on the 850 hPa level.
• While potential temperature advection is valuable for understanding adiabatic processes and air mass transformations during vertical motion, the presented study focused on the direct impact of horizontal thermal advection on the isobaric temperature field. Temperature advection on isobaric surfaces was chosen for the analysis because this approach directly relates to processes contributing to baroclinic instability. This approach directly diagnoses the immediate contribution to temperature changes at specific isobaric levels (850 hPa). Temperature gradients on isobaric surfaces are a key component of baroclinicity, and analyzing temperature advection on these surfaces allows for a direct comparison and understanding of how these processes interact at specific altitudes. Nevertheless, I acknowledge that an accompanying analysis of potential temperature advection could offer additional valuable insights, particularly concerning diabatic processes and air mass conservation during strong vertical motions. Furthermore, this could be an avenue for future detailed studies.
• The level at which the calculations were made was added to the methodology section.

Martineau, P., Behera, S.K., Nonaka, M., Nakamura, H. and Kosaka, Y., 2024. Seasonally dependent increases in subweekly temperature variability over Southern Hemisphere landmasses detected in multiple reanalyses. Weather and Climate Dynamics, 5(1), pp.1-15.

Al-Mutairi, M., Labban, A., Abdeldym, A., Alkhouly, A., Abdel Basset, H. and Morsy, M., 2023. Diagnostic Study of a Severe Dust Storm over North Africa and the Arabian Peninsula. Atmosphere, 14(2), p.196.

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(2) Following the previous point, relative vorticity is used as a diagnostic for this study. However, within the methodology section, the author doesn't mention what levels at which relative vorticity will be addressed. Furthermore, since the extratropical cyclone in this study is associated with the upper-tropospheric troughs and ridges, it would be useful to include vorticity advection as a diagnostic (especially since vorticity tendency is related to cyclogenesis).

• Regarding the specific levels utilized for the relative vorticity analysis, I acknowledge that these should be explicitly stated in the methodology.
• The analysis involved examining relative vorticity at standard isobaric levels crucial for diagnosing the cyclone's structure and forcing mechanisms. Specifically, 850 hPa was analyzed to track the low-level cyclonic circulation (Catto et al., 2010; Seiler & Zwiers, 2016), while 300 hPa (the below figure) was examined to assess the evolution of the upper-level trough/ridge system and associated jet dynamics influencing the cyclone. Examining both these levels provided a comprehensive understanding of the cyclone's vertical structure and the linkage between surface development and upper-tropospheric forcing. However, for the specific purpose of tracking the cyclone's center and presenting the primary low-level rotational signature, the 850 hPa level was selected for display and detailed analysis in the results section. Relative vorticity at 850 hPa, computed from the zonal and meridional wind components, served as the key diagnostic for identifying and following the temporal evolution of the maximum vorticity center, thus defining the cyclone track presented. The level at which the calculations were made was added to the methodology section.
• I fully agree with the reviewer regarding the critical importance of vorticity advection as a diagnostic tool for understanding cyclogenesis, especially in the context of upper-level forcing mechanisms. Indeed, the principle that Positive Vorticity Advection aloft contributes significantly to upper-level divergence, a process linked to the jet stream dynamics identified in our conclusions, is a cornerstone of cyclogenesis theory. Recognizing that the detailed dynamics of vorticity advection are thoroughly covered in numerous well-established meteorological studies (e.g. Kouroutzoglou et al 2015; Flaounas, E., Davolio, S., Raveh-Rubin, S., Pantillon, F., Miglietta, M.M., Gaertner, M.A., Hatzaki,et al., 2022; Pinto, et al., 2014; Catto 2016; Raveh‐Rubin and Flaounas 2017; Reedand Albrigh 1986; Wash et al., 1990) , our manuscript aimed to build upon this existing knowledge. Therefore, instead of an extensive reiteration of these fundamental principles, I focused on demonstrating the consistency of my specific observations with these dynamics and cited key previous studies whose findings on vorticity advection corroborate our results for this particular cyclone. This was a choice to avoid redundancy and to maintain focus on the novel aspects and specific analysis of the case study presented.

Kouroutzoglou, J., Flocas, H.A., Hatzaki, M., Keay, K., Simmonds, I. and Mavroudis, A., 2015. On the dynamics of a case study of explosive cyclogenesis in the Mediterranean. Meteorology and Atmospheric Physics, 127, pp.49-73.

Flaounas, E., Davolio, S., Raveh-Rubin, S., Pantillon, F., Miglietta, M.M., Gaertner, M.A., Hatzaki, M., Homar, V., Khodayar, S., Korres, G. and Kotroni, V., 2022. Mediterranean cyclones: Current knowledge and open questions on dynamics, prediction, climatology and impacts. Weather and Climate Dynamics, 3(1), pp.173-208.

Pinto, J.G., Gómara, I., Masato, G., Dacre, H.F., Woollings, T. and Caballero, R., 2014. Large‐scale dynamics associated with clustering of extratropical cyclones affecting Western Europe. Journal of Geophysical Research: Atmospheres, 119(24), pp.13-704.

Catto, J.L., 2016. Extratropical cyclone classification and its use in climate studies. Reviews of Geophysics, 54(2), pp.486-520.

Raveh‐Rubin, S. and Flaounas, E., 2017. A dynamical link between deep Atlantic extratropical cyclones and intense Mediterranean cyclones. Atmospheric Science Letters, 18(5), pp.215-221.

Reed, R.J. and Albright, M.D., 1986. A case study of explosive cyclogenesis in the eastern Pacific. Monthly Weather Review, 114(12), pp.2297-2319.

Wash, C.H., Heikkinen, S.H., Liou, C.S. and Nuss, W.A., 1990. A rapid cyclogenesis event during GALE IOP 9. Monthly weather review, 118(2), pp.234-257.

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(3) At some points, the AKE analysis obscures some dynamical points that are relevant.

• For example, since jet stream dynamics strongly dictates the cyclone in this study, it would be expected that there would be significant ageostrophic flow associated with the jet stream, which should produce enhanced upper-troposphere divergence and convergence (depending upon the location of the jet stream to the surface cyclone center).
• Furthermore, as the author notes in lines 506 - 513, there is a clear coupling between the surface cyclone and the upper-tropospheric vorticity patterns. This is to be expected because boundary layer pumping and upper-troposphere divergence affect the sea-level pressure tendency and the vorticity tendency. This coupling should also be influence the interaction between the surface fronts associated with the cyclone and the upper-tropospheric troughs.

It would be useful if the author shows how the AKE analysis extends and/or support our current dynamical understanding of the relationship between fronts, jets, and cyclones.

• I thank the reviewer for their insightful question regarding the AKE analysis.
• The AKE analysis conducted directly quantifies the energetic impact of ageostrophic flows associated with the jet stream. Specifically, AKE budget terms, including "generation by cross-contour flow" and the "conversion of AAPE through cross-isobaric flow," measure how these ageostrophic motions, which drive upper-level divergence and convergence, contribute significantly to the cyclone's kinetic energy. Analysis results revealed that such generation was a dominant energy source and that jet activity was a principal driver of AKE.
• The AKE budget's "AAPE to AKE conversion" term (related to vertical motions and thermal contrasts) provides a quantitative measure of the energy released during baroclinic development. This term directly reflects the vertical coupling between surface features (like fronts and boundary layer processes) and upper-level troughs. This coupling results in energetic consequences, which my study found to be the main source for the AKE.
• The AKE analysis extends traditional synoptic interpretations by offering a quantitative energetic framework. It helps identify and rank the dominant energy sources, sinks, and transformations (e.g., the primary role of jet streams and baroclinic conversion in this case), thereby deepening the understanding of how dynamical features like fronts, jets, and troughs contribute to the cyclone's lifecycle and intensity.
• These valuable points regarding the explicit linkage of AKE budget terms to specific dynamical processes like ageostrophic circulations and baroclinic coupling will certainly be taken into account. Indeed, my future studies will further emphasize them to enhance the interpretability and dynamical insights provided by energy budget analyses.
• As suggested, I have added paragraphs in the Results and Discussion section that focus on the relationships among fronts, jet streams, and cyclones, based on the AKE analysis.

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(4) In the abstract and within the Section 3.1, the author acknowledges that diabatic processes also play a role in evolution of the cyclone, but this point is not developed in the paper.  Previous research has shown that the period of most rapid deepening for a midlatitude cyclone occurs when heavy precipitation develops poleward and westward of the cyclone center. This is due to the fact that the associated latent heat release from cloud condensation can (1) add energy to the system, (2) focus and intensify the vertical motion pattern by reducing the static stability, and (3) produce a positive feedback between sensible and latent heat fluxes and cyclogenesis. This is known as the self-development paradigm, and the distribution of precipitation matches Figures 5-6. It would be useful if the author provides additional detail on how the presence of clouds and precipitation affect the dynamical evolution of the cyclone.

• I thank the reviewer again for this highly relevant and constructive point regarding the role of diabatic processes. I agree that these processes, particularly latent heat release from condensation, are critical to the evolution and intensification of mid-latitude cyclones, and I acknowledge that, while mentioned, this aspect was not fully discussed in the original manuscript.
• I especially appreciate the reviewer's observation that the precipitation patterns in Figures 5-6 align with the characteristics of the 'self-development paradigm,' notably the presence of heavy precipitation poleward and westward of the cyclone center during its intensification. This strongly suggests that LHR played a significant role in this case.
• In the revised manuscript, I have expanded my discussion on this topic by adding paragraphs to qualitatively analyze the observed precipitation patterns (Figures 5-6) in relation to the cyclone's intensification and the 'self-development paradigm'.

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LINE 156 - At what levels will you be assessing temperature advection (i.e. 925 hPa, 850 hPa, etc)? Or will you be performing a layer-averaged temperature advection (i.e. 925-850-hPa thermal advection)?

• Information regarding the level at which the calculations were made and the reason for choosing it has been added to the methodology section and included in the answer to the first point.

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LINE 166- Similar to the above question, at what levels will you be assessing vorticity? Also, since you are examining the evolution of a cyclone, why not include vorticity advection?

• Information regarding the level at which the calculations were made has been added to the methodology section and included in the answer to the second point.

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LINE 283 - Based on Figure 4(e), a better explanation would be that the jet stream advected the cyclone eastward.

• As suggested, the sentence has been modified.

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LINE 398 - This would be an ideal time to discuss how the development of clouds and precipitation affects the dynamic evolution of the cyclone.  Previous research has shown that the period of most rapid deepening for a midlatitude cyclone occurs when heavy precipitation develops poleward and westward of the cyclone center. This is due to the fact that the associated latent heat release from cloud condensation can (1) add energy to the system, (2) focus and intensify the vertical motion pattern by reducing the static stability, and (3) produce a positive feedback between sensible and latent heat fluxes and cyclogenesis.

• As suggested, the discussion has been added to the manuscript.

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LINE 412 - Why was this level chosen? Why not choose the entire boundary layer by examining 925-850-hPa temperature advection?

• The answer to this question was provided previously.

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LINE 420 - Dynamically, it is a maximum in warm advection that is associated with rising motion, whereas a maximum in cold advection is associated with sinking motion.

• The sentence has been modified.

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LINE 508 - It should be noted that this matches our expectations. Boundary layer pumping and upper-tropospheric divergence affects the sea-level pressure tendency and the vorticity tendency.

• The sentence has been modified.

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LINE 535 - What is the suspected cause of this behavior?

• This pattern of changes in the local rate of Atmospheric Kinetic Energy at different levels suggests a complex interplay of AKE generation, dissipation, and redistribution by transport processes, likely associated with the evolution of the cyclone and its interaction with the upper-level jet stream.

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LINE 557 - This should be explained in more detail. Typically upper-tropospheric flow is approximately geostrophic so there should be relatively minor flow across geopotential height contours.

• While upper-tropospheric flow is often described as approximately geostrophic, meaning the wind tends to blow parallel to the geopotential height contours, it's also a region where significant Atmospheric Kinetic Energy (AKE) generation can occur. This generation fundamentally relies on flow across these contours (i.e., an ageostrophic component of the wind doing work on the pressure field). Strong generation of AKE by ageostrophic flow (−V⋅∇Φ) is typically associated with the jet stream at these altitudes. Within jet streak regions (e.g., entrance/exit regions) or in association with amplifying baroclinic waves, ageostrophic winds performing work on the pressure field can locally generate significant AKE. The cyclone's intensification or the propagation/strengthening of an associated jet streak would lead to such generation.
• As suggested, the sentence has been modified.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

1). For scientific contribution and originality, explain explicitly highlight the novelty of the case (e.g., the rare spatial extension of the cyclone’s impact to the Arabian Peninsula or dust storm implications) and how this work is different from other cyclones studies.

2). For quantitative interpretation of AKE components, include time-series plots and vertical profiles of AKE terms (e.g., GKE, HFKE, DKE). Quantify the relative magnitude of each term and link them to the cyclone’s structural evolution, especially the baroclinic-to-barotropic transition.

3). Integrate time series of observed surface wind or pressure data and compare with ERA5 outputs for validation using surface observation. Consider using dust index or visibility data to validate the satellite-derived dust structures and cyclone intensity.

4). For language quality, The manuscript should undergo professional English editing. Improve clarity and conciseness in scientific explanations. 

Comments on the Quality of English Language

Correct English expressions are needed in many areas throughout the paper as follows:

1). “The cyclone was developed by upper-level trough during early February 2006.” >> “The cyclone developed under the influence of an upper-level trough in early February 2006.”

2). “This process is a fundamental mechanism for the transformation of potential energy into AKE.” >> “This process transforms potential energy into atmospheric kinetic energy (AKE), playing a fundamental role in cyclone dynamics.”

3). “A wide dust structure appeared in the satellite image.”>> “Satellite imagery revealed an extensive dust plume associated with the cyclone’s southern flank.”

4). “The energy term was positive in all layers, which means it acted as a source of AKE.” >>“The positive values of this term across all pressure levels indicate its contribution as a source of kinetic energy throughout the troposphere.”

5). “Figure 5: Time-height diagram for the cyclone case.” >> “Figure 5: Time-height cross section of vertical velocity (ω, Pa/s) and temperature (K) at the cyclone center, illustrating the vertical development of convection during the intensification phase.”

 

Author Response

The corrections required by – Reviewer 2

Journal:                       Climate

Manuscript Number: climate-3611555

Paper Title:                 Synoptic and Dynamic Analysis of an Intense Mediterranean Cyclone: A Case Study
Type:                            Article

Author:                      Ahmad E. Samman

   ------------------------------------------------

• First: Many thanks to the reviewer for his interest in reviewing the research with high accuracy and for all the scientific comments he recommended that helped raise the level of this work.
• Second: Spelling and grammatical errors were corrected, and the paper was carefully reviewed by the author and then by an English language specialist. Many of the sentences in the manuscript have been linguistically checked and polished.
• Third: The introduction, methodology and conclusion were improved.

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Comments and Suggestions for Authors

1). For scientific contribution and originality, explain explicitly highlight the novelty of the case (e.g., the rare spatial extension of the cyclone’s impact to the Arabian Peninsula or dust storm implications) and how this work is different from other cyclones studies.

• I appreciate the reviewer's question regarding the scientific contribution and originality of my work. I agree that clearly articulating the novelty of the case study and how my analysis differentiates it from other Mediterranean cyclone studies is crucial. The primary novelty of this work lies in the unique characteristics of the studied cyclone event itself. This particular cyclone exhibited an exceptionally rare spatial extension of its direct meteorological impact, reaching deep into the Arabian Peninsula. Furthermore, it was associated with a significant and extensive dust storm, a phenomenon not typically a primary focus in studies of mid-latitude cyclone dynamics but which had considerable societal impact in the region. This specific combination of extreme spatial reach and the generation of a major dust event makes this case study highly unusual and scientifically valuable for understanding the full spectrum of cyclone impacts in transitional climates. Beyond the novelty of the case, my work differentiates itself by providing a detailed quantitative analysis of the cyclone's energetics, specifically through the lens of the AKE budget. While AKE budgets have been applied to other cyclones, this study explicitly links the quantitative contributions of specific AKE budget terms, such as the generation by ageostrophic flow associated with jet streams and the conversion of AAPE related to baroclinic processes and latent heat release, to the observed, unique features of this particular cyclone's development and impact, including the large-scale temperature advection patterns and the environment conducive to the observed dust storm. By providing a robust energetic diagnosis of this rare event, this study offers novel insights into how fundamental dynamical processes manifest and contribute to the lifecycle and extreme impacts of cyclones in this specific, under-studied region.
• The scientific contribution and originality, novelty of the case and how this work is different from other cyclone studies have been added at the end of the introduction section.

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2). For quantitative interpretation of AKE components, include time-series plots and vertical profiles of AKE terms (e.g., GKE, HFKE, DKE). Quantify the relative magnitude of each term and link them to the cyclone’s structural evolution, especially the baroclinic-to-barotropic transition.

• I appreciate the reviewer's insightful comment regarding the quantitative interpretation of the AKE components, including their temporal and vertical evolution and linkage to the cyclone's structural changes. I agree that this is crucial for a thorough understanding of the energetics.
• This information is indeed presented in the manuscript, aiming to provide the detailed quantitative interpretation requested:
• Table 1 shows the Time mean of area-averaged of AKE (10⁴J/m²) and AKE budget terms (W/m²) at standard pressure levels during the study period. These values quantify the relative magnitude of each term across various altitudes, essentially presenting the vertical profiles of the time-average budget components.
• Table 2 shows the area average of vertical mean for AKE (10⁴ J/m²) and AKE budget terms (W/m²) for the cyclonic system every six hours during the study period. These data quantify the relative magnitude of each vertically-averaged term over time, providing the time series of the budget components.
• Figure 9 provides a vertical-temporal profile of AKE (10⁴ J/m²(100 hPa)⁻¹) and AKE budget terms (W/m² (100 hPa)⁻¹) for the cyclonic system throughout the study period. This figure visually combines the temporal and vertical evolution, illustrating how the magnitude and distribution of the terms change over time and altitude, which is key for linking them to the cyclone's structural evolution, such as the baroclinic-to-barotropic transition discussed in the text.
• By presenting the time-averaged vertical profiles in Table 1, the vertical-averaged time series in Table 2, and the combined temporal-vertical evolution visually in Figure 9, alongside the discussion in the text, we believe we have addressed the need for quantitative interpretation of the AKE components and their relationship to the cyclone's evolution.

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3). Integrate time series of observed surface wind or pressure data and compare with ERA5 outputs for validation using surface observation. Consider using dust index or visibility data to validate the satellite-derived dust structures and cyclone intensity.

• I thank the reviewer for this highly relevant suggestion regarding the validation of the ERA5 dataset and satellite-derived dust structures using surface observations and dust/visibility data. I fully agree that validation is a critical step, especially when relying on reanalysis data. However, a significant challenge in this study stems from the fact that the cyclone's path was predominantly located over the vast, sparsely populated desert regions of North Africa and the Arabian Peninsula. Surface meteorological observation networks in these areas are extremely limited. Consequently, obtaining a comprehensive time series of surface wind or pressure data with sufficient spatial and temporal density to perform a robust validation of the ERA5 outputs along the entire cyclone's track was not feasible. My primary reliance on the spatially continuous ERA5 reanalysis data was therefore necessitated by these observational limitations in the key development and impact regions.
• ERA5 is the fifth generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate covering the period from January 1940 to the present. ERA5 is produced by the Copernicus Climate Change Service (C3S) at ECMWF. ERA5 provides hourly estimates of a large number of atmospheric, land and oceanic climate variables. The data cover the Earth on a 30 km grid and resolve the atmosphere using 137 levels from the surface up to a height of 80 km. ERA5 includes information about uncertainties for all variables at reduced spatial and temporal resolutions. The ERA5 data record extends over more than 83 years of hourly global three-dimensional fields for many quantities that describe the global atmosphere, land surface, and ocean waves. ERA5 relies on the ingestion of sub-daily in-situ and satellite observations (e.g., GOME, GOME-2A, MLS, Nimbus-7, OMI, SBUV, SCIAMACHY, TOMS (v8.0)) (Hersbach et al., 2020), and the number of these increases from 17,000 per day in 1940 to 25 million per day by 2022. Accordingly, the quality of the reanalysis improves throughout the period. Over the Northern Hemisphere, ERA5 generally provides a reliable representation of the synoptic situation from the early 1940s, and its long-term variability is in line with other datasets. Since its release in 2019, the ERA5 data have been extensively utilized by the scientific community, not least in operational weather centres where, for example, reanalysis are used to assess the impact of observing system changes, to gauge progress in modelling and assimilation capabilities, and to obtain state-of-the-art climatologies to evaluate forecast-error anomalies (e.g., Al-Kallas et al., 2021; Bernet et al., 2023; Krzyścin, 2023; Li et al., 2022; Nerobelov et al., 2022; Wang et al., 2021; Aboelkhair and Morsy, 2024).
• The ERA5 dataset has been rigorously evaluated against observed meteorological variables (Tarek et al., 2020). Numerous studies have demonstrated its accuracy and reliability in representing various atmospheric parameters (Yu et al., 2021; Mihalevich et al., 2022; Velikou et al., 2022; Ibebuchi et al., 2024; Tingting et al., 2024). For example, Krzyścin (2023) compared observed ozone data with ERA5 reanalysis data across 12 European stations from 1980–2020, finding a high degree of agreement with a root mean square error and bias of 3.4% and 0.5%, respectively. Aboelkhair and Morsy (2024) similarly evaluated the agreement between ERA5-estimated Tmax and Tmin values and observed values using R², MBE, and RMSE. Their results further support the accuracy of ERA5 data in representing observed Tmax and Tmin. Additionally, the spatial distributions of RMSE and MBE were found to align closely.
• Similarly, obtaining dense coverage of visibility or dedicated dust index data across the remote desert areas affected by the storm presented significant challenges. While some scattered observations from airports or meteorological stations within or near the affected regions might exist, they are insufficient for a rigorous, spatially extensive validation of the satellite imagery dust features discussed in the manuscript.
• I acknowledge the importance of these validation methods and recognize their value for future studies in areas with denser observation networks. For this specific case study, the inherent data limitations over the desert constrained my ability to perform the comprehensive validations suggested, but the ERA5 reanalysis provides the most complete and consistent depiction available for this event's dynamics over the data-sparse region.

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4). For language quality, The manuscript should undergo professional English editing. Improve clarity and conciseness in scientific explanations. 

• Prior to this revision, the manuscript underwent professional English editing to enhance its clarity and style. Spelling and grammatical errors were corrected, and the paper was carefully reviewed by the author and then by an English language specialist. Consequently, the manuscript's sentences have been thoroughly checked and polished. In addition to this professional editing, I have carefully reviewed the manuscript again in light of your comment and have made further revisions throughout the text to improve the clarity and conciseness of the scientific explanations.

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Comments on the Quality of English Language

Correct English expressions are needed in many areas throughout the paper as follows:

1). “The cyclone was developed by upper-level trough during early February 2006.” >> “The cyclone developed under the influence of an upper-level trough in early February 2006.”

• This sentence does not exist in the manuscript (The cyclone was developed by upper-level trough during early February 2006)

2). “This process is a fundamental mechanism for the transformation of potential energy into AKE.” >> “This process transforms potential energy into atmospheric kinetic energy (AKE), playing a fundamental role in cyclone dynamics.”

• The sentence has been modified

 

3). “A wide dust structure appeared in the satellite image.”>> “Satellite imagery revealed an extensive dust plume associated with the cyclone’s southern flank.”

• The sentence has been modified

4). “The energy term was positive in all layers, which means it acted as a source of AKE.” >>“The positive values of this term across all pressure levels indicate its contribution as a source of kinetic energy throughout the troposphere.”

• ''all atmospheric layers'' changed to ''throughout the troposphere''

5). “Figure 5: Time-height diagram for the cyclone case.” >> “Figure 5: Time-height cross section of vertical velocity (ω, Pa/s) and temperature (K) at the cyclone center, illustrating the vertical development of convection during the intensification phase.”

• Figure 5 displays the satellite image taken during the study period, highlighting dust (pink/purple) and clouds (brown/orange), not a vertical Time-height diagram for the cyclone case.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Please see attached. 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

Thank you very much for your thorough and insightful second-round review of the manuscript.

I sincerely appreciate your recognition of the improvements made, particularly regarding the clarification of the study’s novelty, the integration of the atmospheric kinetic energy (AKE) diagnostics, and the overall structure. Your remarks about the study’s contribution to Mediterranean cyclone literature and mesoscale dynamical analysis in arid regions are especially encouraging.

I have addressed the minor suggestions you noted:

1. The captions for Figures 9 have been expanded to better clarify the axis variables and physical interpretation, aiming to make the diagnostics more accessible to a broader readership.
2. I have reviewed all unit notations to ensure consistency across the manuscript, tables, and figures.

Once again, thank you for your constructive and supportive feedback throughout the review process.