the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 17 Mar 2026
Decadal ocean observations in the Northwestern Mediterranean: insights from the MOOSE-GE cruises
Abstract. The annual MOOSE-GE cruise series is the backbone of the MOOSE regional ocean observing system providing a unique dataset to observe and understand large-scale physical, biogeochemical and biological processes in the northwestern Mediterranean basin, a key region that is responding to climate change faster than many other parts of the world. These cruises address major scientific challenges, such as monitoring the variability and impact of deep and intermediate convection, which plays a crucial role in deep-water ventilation, coastal–open ocean exchanges, and the evolution of phytoplankton production in this highly dynamic system. They also allow the assessment of climate change effects on ocean physics, marine biodiversity, biological resources, and seawater chemistry, including oxygen, nutrients, and dissolved carbon. Sustained observations are required to track rapid trends such as increasing temperature and salinity in intermediate and deep waters, declining oxygen concentrations, nutrients and carbonate system inter-annual variabilities, expected increased stratification of the water column and variations in heat and salt contents. These long-term datasets are indispensable both for climate model validation and process studies, as well as for assessing the environmental status of the Mediterranean Sea. The data can be accessed at https://doi.org/10.18142/235 (Testor et al., 2010), https://doi.org/10.17882/99825 (Bosse et al., 2024), https://doi.org/10.17882/44411 (Bosse et al., 2025), https://doi.org/10.17882/45980 (Durrieu de Madron et al., 2024), https://doi.org/10.17882/43749 (Coppola et al., 2025), https://doi.org/10.17882/99865 (Dimier et al., 2024).
- Preprint
(4475 KB) - Metadata XML
- BibTeX
- EndNote
Status: final response (author comments only)
-
AC1: 'Comment on essd-2026-127', Laurent Coppola, 02 Apr 2026
-
AC4: 'Reply on AC1', Laurent Coppola, 30 May 2026
This part has been integrated in the new revised manuscript
Citation: https://doi.org/10.5194/essd-2026-127-AC4
-
AC4: 'Reply on AC1', Laurent Coppola, 30 May 2026
-
RC1: 'Comment on essd-2026-127', Giuseppe M.R. Manzella, 05 May 2026
Comments on essd-2026-127
Decadal ocean observations in the Northwestern Mediterranean: insights from the MOOSE-GE cruises
By Coppola et al.
General comment
The paper presents very interesting data and is very comprehensive in its descriptions of technologies and control analysis methodologies. The research team's efforts over the years are very important for assessing environmental changes in a critical area like the northwestern Mediterranean.
The few criticisms concern the excessive use of acronyms, which are often indecipherable to readers unfamiliar with the scientific literature on the Mediterranean and European regions. These acronyms should be accompanied by references. Another small point concerns the fact that the campaigns are held in summer, but in the introduction, the discussion of environmental characteristics during that season is overshadowed by that of essentially winter-related phenomena (even though these are very important and have repercussions in the medium and long term).
I find the bibliography limited to relatively recent research, but the issues discussed in the introduction are the subject of publications from the 1980s and 1990s, many by French authors (e.g., Bethoux). It's a shame that the works of these ‘old’ authors are not included in the bibliography of a well-written article like this.
My opinion is that small adjustments may therefore be appropriate for the publication of this important article.
Special comments
Line 48. The statement 'deep-water renewal time of only a few decades' seems to me to be a bit inaccurate. There are several works by Bethoux (see, for example, Behoux and Gentili 1999 - https://doi.org/10.1016/S0924-7963(98)00069-4 and the references given therein) that lead to deep-water renewal times of several decades. I think it is appropriate to cite the reference by Bethoux and Gentili alongside that of Schroeder et al., 2016 (line 49). On the trends of the Levantine water it could be useful to also cite the work of Astraldi et al (1994): The Seasonal and Interannual Variability in the Ligurian-Provençal Basin - https://doi.org/10.1029/CE046p0093Digital Object Identifier (DOI) and of Sparnocchia et al (1994) The Interannual and Seasonal Variability of the MAW and LIW Core Properties in the Western Mediterranean Sea- https://doi.org/10.1029/CE046p0117Digital Object Identifier (DOI)
Line 83. Many acronyms HyMeX, MERMeC, ChArMEx, (not only here but throughout the article) Each of them must be accompanied by a brief description of the objectives and related bibliography.
Linea 92. The system is structured around four thematic work packages: is it a system or a programme? Does this only refer to MOOSE or also to the other HyMeX, MERMeX, and ChArMEx? It's unclear.
Linee 99 – 100. provide a yearly basin-scale overview in summer of the Northwestern Mediterranean Sea from surface to bottom. This introduction doesn't clearly identify the summer characteristics of the Ligurian-Provençal basin. Some information should be included.
Linea 135. CNRM, S. Somot – under the responsibility of S. Somot? Please specify. Is there a publication by Somot that can be cited?
Linea 188 – 189. national projects (e.g., RIOMAR, FUTURE-OBS) and European initiatives involving several ERICs (e.g., Horizon EUROSEA, EA-RISE, and currently GEORGE). Please specify the purposes of these projects.
Linea 240. quality code (WOCE code in most cases). Does this mean that in other cases authors are using different vocabularies (SeaDataNet?). Details please.
Other corrections
Linea 78 : led by CNRS-led (too many ‘led’)
Linea 257: fluorometer (Chlesea), I suppose is Chelsea
Citation: https://doi.org/10.5194/essd-2026-127-RC1 -
AC2: 'Reply on RC1', Laurent Coppola, 30 May 2026
We thank Reviewer 1 for these comments. Our responses are provided below:
Special comments
Line 48. The statement 'deep-water renewal time of only a few decades' seems to me to be a bit inaccurate. There are several works by Bethoux (see, for example, Behoux and Gentili 1999 - https://doi.org/10.1016/S0924-7963(98)00069-4 and the references given therein) that lead to deep-water renewal times of several decades. I think it is appropriate to cite the reference by Bethoux and Gentili alongside that of Schroeder et al., 2016 (line 49). On the trends of the Levantine water it could be useful to also cite the work of Astraldi et al (1994): The Seasonal and Interannual Variability in the Ligurian-Provençal Basin - https://doi.org/10.1029/CE046p0093Digital Object Identifier (DOI) and of Sparnocchia et al (1994) The Interannual and Seasonal Variability of the MAW and LIW Core Properties in the Western Mediterranean Sea- https://doi.org/10.1029/CE046p0117Digital Object Identifier (DOI)
These references have been added in the introduction section
Line 83. Many acronyms HyMeX, MERMeC, ChArMEx, (not only here but throughout the article) Each of them must be accompanied by a brief description of the objectives and related bibliography.
The paragraph has been modified and these acronyms have been removed (see comments from reviewer 2).
Linea 92. The system is structured around four thematic work packages: is it a system or a programme? Does this only refer to MOOSE or also to the other HyMeX, MERMeX, and ChArMEx? It's unclear.
Same comment. MOOSE is a French national observation program (or service) providing an integrated, multidisciplinary observing system for the northwestern Mediterranean Sea
Linee 99 – 100. provide a yearly basin-scale overview in summer of the Northwestern Mediterranean Sea from surface to bottom. This introduction doesn't clearly identify the summer characteristics of the Ligurian-Provençal basin. Some information should be included.
In page 4, we have added: "Conducted in summer, when the water column exhibits its strongest seasonal stratification, with a shallow thermocline isolating the surface mixed layer from the deeper Ligurian-Provençal and Gulf of Lion basins, these cruises capture the system at a critical hydrological state..."
Linea 135. CNRM, S. Somot – under the responsibility of S. Somot? Please specify. Is there a publication by Somot that can be cited?
We have added Ruti et al. 2016, which is the founding paper of Med-CORDEX, an international climate modelling initiative for the Mediterranean. The paper highlights the importance of observations for evaluating models.
Ruti PM, Somot S, Giorgi F, Dubois C, Flaounas E, Obermann A, Dell’Aquila A, Pisacane G, Harzallah A, Lombardi E, Ahrens B, Akhtar N, Alias A, Arsouze T, Aznar R, Bastin S, Bartholy J, Béranger K, Beuvier J, Bouffies-Cloché S, Brauch J, Cabos W, Calmanti S, Calvet J-C, Carillo A, Conte D, Coppola E, Djurdjevic V, Drobinski P, Elizalde-Arellano A, Gaertner M, Galàn P, Gallardo C, Gualdi S, Goncalves M, Jorba O, Jordà G, L'Heveder B, Lebeaupin-Brossier C, Li L, Liguori G, Lionello P, Maciàs D, Nabat P, Onol B, Raikovic B, Ramage K, Sevault F, Sannino G, Struglia MV, Sanna A, Torma C, Vervatis V (2016) MED-CORDEX initiative for Mediterranean Climate studies. Bull. Amer. Meteor. Soc., 97(7), 1187-1208, July 2016, doi: http://dx.doi.org/10.1175/BAMS-D-14-00176.1
Linea 188 – 189. national projects (e.g., RIOMAR, FUTURE-OBS) and European initiatives involving several ERICs (e.g., Horizon EUROSEA, EA-RISE, and currently GEORGE). Please specify the purposes of these projects.
This paragraph has been modified and simplified (see comments from reviewer 2)
Linea 240. quality code (WOCE code in most cases). Does this mean that in other cases authors are using different vocabularies (SeaDataNet?). Details please.
In section 3 some details have been added: "SeaDataNet quality flags (QF) for CTD and bottle data archiving (SISMER), OceanSITES QF for mooring time series (CORIOLIS) and Argo/OceanSITES scale for gliders with some specific real-time and delayed mode quality codes (Hebden et al., 2019).”
Other corrections
Linea 78 : led by CNRS-led (too many ‘led’)
This sentence has been removed (see comments for reviewer 2)
Linea 257: fluorometer (Chlesea), I suppose is Chelsea
Yes indeed it was modified
Citation: https://doi.org/10.5194/essd-2026-127-AC2
-
AC2: 'Reply on RC1', Laurent Coppola, 30 May 2026
-
RC2: 'Comment on essd-2026-127', Anonymous Referee #2, 12 May 2026
The paper describes an impressive multiparameter/multiplatform datasets in a hot spot region of the thermohaline circulation of the Mediterranean Sea. This is of high interest for the scientific community. On the other hand, large part of the dataset has been already presented and published in many scientific papers. The draft itself seems a little bit immature, sometimes it sounds to me more like a post-cruise final report rather than a dedicated datapaper presenting a specific dataset.
- A geographical map showing all geographical names (Nice, Marseille, Sardinia, ecc…) cited in the text as well as major oceanographic features (i.e, northern current) is necessary for readers unfamiliar with the region
- Section 1 and 2 have several concepts repeated twice or more. The two sections should be harmonised so to avoid repetitions.
- Several details are somewhat beyond a data paper, that is primarily meant to describe the dataset, not the cruises. Happy to read that the ships are hosting students (l. 182-l. 189) or that the ecological footprint is taken into account (l.191- l.198), however these information are just making the paper longer. Please consider compressing these info in a 1 - 2 lines long statement.
- There are many acronyms that are not spelled out, or cited Programmes’ names that does not add much info to the reader. The national and international context, in my opinion, should be shortened/synthetised, presenting only the most relevant info.
- Section 3.10 Moorings: it would have been nice to see a figure with the design
- Section 3.11 happy to hear you that you have been deploying ARGOs, but this is not part of the core dataset. Maybe move (duly shortened) in the “strategy” section?
- Section 5.1: the two paragraphs have similar concepts repeated twice (e.g., years with mixing down to bottom vs years w/out) Please harmonize and avoid repetitions.
- Section 5.3. Much of this section should go to the “strategy” section, some into the “methods” section, very little remain about “results”. I would expect more data exploitation, e.g., some exploratory statistics and plots. I wonder also if it is available more than what is presented already in Lescot et al., FMASR 2026.
- Section 5.4: this section is OK for reporting to the funding agency, but in a data paper it is loosely connected and just making the paper longer.
- Section 5.5. Again, as the previous remark. I wonder if this section wouldn’t be more useful at the end of the “strategy” section, carefully shortened. Even as a closing remark of the conclusion section, duly synthesized.
- Figure 2: there is clearly some OA in the background. Somewhere (in the main text? in the caption?) it should be acknowledged and a little bit detailed.
- References should be carefully checked. I have found some inconsistencies (e.g., l.169 Bosse et al., 2017 not listed in the references, or Schroeder et al., 2017 in the references is a repetition of Schroeder et al., 2016 … maybe others, I didn’t check all … In addition, l. 265 “(Testor et al., 2010: MOOSE-GE cruise series, https://doi.org/10.18142/235)” should be just Testor et al., 2010… just as in l. 277 Bosse et al., (2024) is enough. Some manuals used for QC or protocols may be relegated in the references instead of being cited fully in the main text (e.g., l. 289).
- Data availability of biodiversity data: I had hard time digging into ECOTAXA (I am not familiar with), finally giving up. There is not a specific DOI to the dataset in the paper. Thus, I did not check this part of the dataset.
- 79 “CNRS-led” Typo?
- 134 SYMPHONIE model. Ref?
- 135 ref for the long term climate modelling instead of CNRM, S. Somot?
- 259 something is wrong with the grammar: missing words?
Citation: https://doi.org/10.5194/essd-2026-127-RC2 -
AC3: 'Reply on RC2', Laurent Coppola, 30 May 2026
We are grateful to Reviewer 2 for these comments. Please find our responses below:
A geographical map showing all geographical names (Nice, Marseille, Sardinia, ecc…) cited in the text as well as major oceanographic features (i.e, northern current) is necessary for readers unfamiliar with the region
The map (figure 1) has been modified with geographical names and major oceanographic currents/fronts
Section 1 and 2 have several concepts repeated twice or more. The two sections should be harmonised so to avoid repetitions
The sections 1 & 2 have been harmonised to avoid repetitions
Several details are somewhat beyond a data paper, that is primarily meant to describe the dataset, not the cruises. Happy to read that the ships are hosting students (l. 182-l. 189) or that the ecological footprint is taken into account (l.191- l.198), however these information are just making the paper longer. Please consider compressing these info in a 1 - 2 lines long statement. There are many acronyms that are not spelled out, or cited Programmes’ names that does not add much info to the reader. The national and international context, in my opinion, should be shortened/synthetised, presenting only the most relevant info.
Some sentences have been shortened to present mainly the relevant information of the program and the dataset
Section 3.10 Moorings: it would have been nice to see a figure with the design
Moorings design has been added in a new figure (Figure 2)
Section 3.11 happy to hear you that you have been deploying ARGOs, but this is not part of the core dataset. Maybe move (duly shortened) in the “strategy” section?
Section 3.11 have been removed and a condensed Argo floats strategy has been added in section 2 (line 166, bullet 3)
Section 5.1: the two paragraphs have similar concepts repeated twice (e.g., years with mixing down to bottom vs years w/out) Please harmonize and avoid repetitions.
Section 5.1 has been harmonised to avoid repetitions
Section 5.3. Much of this section should go to the “strategy” section, some into the “methods” section, very little remain about “results”. I would expect more data exploitation, e.g., some exploratory statistics and plots. I wonder also if it is available more than what is presented already in Lescot et al., FMASR 2026.
We thank the reviewer for this constructive comment. We have moved the strategy and methods content from Section 5.3 to Sections 2 and 3.9 respectively. Regarding data exploitation, we agree that more analytical content strengthens this section. We have now explicitly cited and summarized the key findings from Lescot et al. (2026): plankton community structure in the 2017–2019 cruises was primarily shaped by organism size and water column depth; alpha diversity was highest in small size fractions (0.2–3 and 3–180 µm) at the surface and DCM; temporal differences between cruises were mainly detected in Niskin bottle samples (diatoms and dinoflagellates), while net tow samples showed weaker variability; and physical clustering revealed cross-shelf and basin-scale gradients aligning with community structure at OTU level for small fractions. Spatial structuring of zooplankton biomass and abundance (north–south gradient, three regional groups) is retained from Feliu (2021), which remains the relevant reference for those findings. We have also explicitly noted that while Lescot et al. (2026) constitutes the main published analysis to date, a substantially larger volume of UVP and net-based imaging data collected across the full MOOSE-GE time series (2012–present) remains available in EcoTaxa/EcoPart, representing a significant opportunity for future exploitation. A new metabarcoding dataset from the four campaigns from 2021 to 2024 have been recently sequenced. Finally, we have added a reference to Llopis Monferrer et al. (2022, doi: 10.3389/fmars.2022.895995), which provides complementary results on siliceous Rhizaria diversity and distribution from MOOSE-GE cruises.
Section 5.4: this section is OK for reporting to the funding agency, but in a data paper it is loosely connected and just making the paper longer.
We do not agree with the reviewer on this aspect. Section 5.4 is an essential section to demonstrate the links between in situ observing system like MOOSE and various modelling applications. We list the various data usages made by the modelling community with the MOOSE dataset over the recent years with specific references to the literature allowing the reader to dig in a specific applications if needed. We consider that this section gives examples of original applications of in-situ data for modelling purposes such as model initialization, model validation, model development or model-observation blending.
Section 5.5. Again, as the previous remark. I wonder if this section wouldn’t be more useful at the end of the “strategy” section, carefully shortened. Even as a closing remark of the conclusion section, duly synthesized.
Section 5.5 has been removed and a condensed version has been moved to the conclusion (section 6), as it addresses future perspectives such as OSSE work
Figure 2: there is clearly some OA in the background. Somewhere (in the main text? in the caption?) it should be acknowledged and a little bit detailed.
This is correct that the fig. 2 was unclear regarding the interpolation method. We have now added the required details to the figure caption.
References should be carefully checked. I have found some inconsistencies (e.g., l.169 Bosse et al., 2017 not listed in the references, or Schroeder et al., 2017 in the references is a repetition of Schroeder et al., 2016 … maybe others, I didn’t check all … In addition, l. 265 “(Testor et al., 2010: MOOSE-GE cruise series, https://doi.org/10.18142/235)” should be just Testor et al., 2010… just as in l. 277 Bosse et al., (2024) is enough. Some manuals used for QC or protocols may be relegated in the references instead of being cited fully in the main text (e.g., l. 289).
The references have been checked and updated
Data availability of biodiversity data: I had hard time digging into ECOTAXA (I am not familiar with), finally giving up. There is not a specific DOI to the dataset in the paper. Thus, I did not check this part of the dataset.
We thank the reviewer for this comment and apologize for the difficulty in accessing the imaging data. EcoTaxa is a web application for the taxonomic classification and management of plankton images, and all MOOSE-GE imagery data are publicly accessible through individual project pages organized by instrument and year (see the new Table 4)
The complete list of EcoTaxa projects for MOOSE-GE cruises is provided in a new table added to the Data Availability section of the revised manuscript (Table 4). It covers four instruments (ZooScan, UVP, FlowCam, and Planktoscope) spanning 2012–2024, with a total of over 5.6 million images across 34 projects. Each project is directly accessible via its URL. Validation status varies by project, reflecting the progressive nature of taxonomic annotation: ZooScan datasets are fully or largely validated (87–100%), while most UVP, FlowCam, and Planktoscope datasets remain at early validation stages and represent the raw imaging resource available for future exploitation.
79 “CNRS-led” Typo?
It has been removed
134 SYMPHONIE model. Ref?
Marsaleix P., F. Auclair, J. W. Floor, M. J. Herrmann, C. Estournel, I. Pairaud, and C. Ulses, Energy conservation issues in sigma-coordinate free-surface ocean models, Ocean Modell., 20, 61–89, 2008.
135 ref for the long term climate modelling instead of CNRM, S. Somot?
Samuel et al., 2006: Somot, S., Sevault, F. & Déqué, M. Transient climate change scenario simulation of the Mediterranean Sea for the twenty-first century using a high-resolution ocean circulation model. Clim Dyn 27, 851–879 (2006). https://doi.org/10.1007/s00382-006-0167-z - correct ?
259 something is wrong with the grammar: missing words?
This sentence has been corrected: "For each cruise, sensors had been recently calibrated by the manufacturer (Seabird) and rotated every year, while the general system configuration remained exactly the same, except on occasions where sensor damage required temporary substitution"
Citation: https://doi.org/10.5194/essd-2026-127-AC3
-
RC3: 'Comment on essd-2026-127', Anonymous Referee #3, 04 Jun 2026
General Comments
The paper describes a highly valuable dataset that is crucial for understanding both regional oceanographic and biogeochemical processes. Long-term datasets from hotspot regions such as the Mediterranean Sea are essential for analyzing ongoing environmental changes. Therefore, this work has significant relevance and potential impact for the scientific community.
The dataset has already been used in a large number of publications. For this reason, this paper represents an important opportunity to further improve the dissemination of the dataset, ensuring compliance with FAIR and TRUST principles. Additionally, the variables collected should be better aligned with GOOS frameworks, explicitly referencing Essential Ocean Variables (EOVs) and Essential Biological Variables (EBVs).
However, a substantial reorganization of the manuscript is needed to improve both clarity and overall quality. At present, the draft appears poorly structured, and the presentation of the datasets is often confusing and unclear.
Specific Comments
Introduction
The observatory should be better contextualized within the broader framework of existing ocean observing systems such as EURO-ARGO and EMSO. Its unique features should be highlighted, particularly in relation to the spatial and temporal scales of the processes it can resolve. This point is especially important given the manuscript’s mention of its role as a reference site for ARGO floats and EMSO moorings.Line 262
The citations Uchida et al., 2010 and McTaggart et al., 2010 are missing from the reference list.Lines 475–478 / Table 3
The full list of datasets should be presented clearly in a table (e.g., Table 3), but there are several issues:- The DOI provided for CTD and bottle sampling is identical and leads to a cruise list page (MOOSE-GE) where datasets are not directly accessible.
- Another link (line 477) points to the DYFAMED dataset, which includes CTD and bottle sampling.
This needs clarification: where can users access the complete and correct datasets?
Overall, the dataset presentation is confusing and poorly organized.
Data Accessibility and FAIR Compliance
Datasets should be organized so that users can easily access them through specific DOIs linked to well-described resources. Each dataset should include proper metadata and use common vocabularies (e.g., for mooring data such as DYFAMED and LION).Line 240 (WOCE reference)
The manuscript refers to WOCE-style bottle sampling, but corresponding datasets are not clearly available in the links provided (Table 3).Table 3
The table should be reorganized:Explicitly link datasets to EOVs/EBVs
Provide correct DOIs that directly resolve to datasets
Some datasets (e.g., UVP, nets, metaB sequences) appear to be missing—this is a critical gap. For some entries, only project numbers are given instead of DOIs
EOV Consistency (Lines 94–96, 125, 229)
EOVs are mentioned multiple times; however, the use is not fully consistent. Harmonization between the text and tables is necessary.Table 2
This table should be revised to:Link variables to EOVs/EBVs where applicable (e.g., subsurface salinity)
Include standardized vocabularies such as NERC L05 (parameters) and L22 (instruments)
Figures and Redundancy
The cruise page (DOI: https://doi.org/10.18142/235) contains figures that are very similar to those presented in the manuscript (e.g., Figure 1 and Figure 6). It would be preferable to modify or remove duplicate material and instead cite the original source.Results Section
Since the dataset has already supported numerous publications, the Results section should be reframed to highlight the scientific impact of this long-term observation effort, including key achievements and contributions to the field.Lines 658–665 should be moved to the Methods section
Lines 670–680 should also be moved to Methods
Citation: https://doi.org/10.5194/essd-2026-127-RC3
Data sets
MOOSE_GE cruises P. Testor et al. https://doi.org/10.18142/235
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 326 | 131 | 33 | 490 | 16 | 27 |
- HTML: 326
- PDF: 131
- XML: 33
- Total: 490
- BibTeX: 16
- EndNote: 27
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
- Figure on TA-DIC: units should be in µmol/kg
- Need to add in the acknowledgment: "We also acknowledge INSU/CNRS and OSU ECCE-Terra for supporting the SNAPO-CO2 facility housed by the LOCEAN laboratory in Paris/France"