the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Moana Ocean Future Climate V1.0: High Resolution Marine Climate Futures For The New Zealand Region
Abstract. We have produced a series of 5 km resolution future climate dynamic downscalings for the ocean surrounding New Zealand covering CMIP6 reference conditions; SSP2-4.5 and SSP3-7.0 emissions trajectories. These downscalings combine the Moana Backbone 5 km resolution ROMS configuration with lateral boundary forcing from the 15 km resolution New Zealand Earth System Model (NZESM) and atmospheric forcing from the New Zealand Regional Climate Model 12 km atmospheric model.
We validated our reference period downscaling against the Moana Ocean Hindcast and find reasonable agreement to the west and north of New Zealand, but significant disagreement in the region of the Sub-Tropical Front to the east and southeast of the domain. This disagreement is consistent with known issues with the version of NZESM used as forcing in this study.
We see similar relative rates of increase in Ocean Heat Content in the upper ocean and mode waters all around New Zealand, but in the deeper ocean the rate of warming is stronger in the Tasman Sea and Antarctic Circumpolar Current than in the Sub Tropical Front East of New Zealand. We examine the occurrence of Marine Heat Waves (MHWs) and find that the use of a “fixed" baseline or one that takes into consideration a long-term warming based on the historical period results in important differences in the estimated number of days under MHWs for mid and end-of-the-century scenarios.
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Status: closed (peer review stopped)
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CEC1: 'Comment on egusphere-2024-1962 - No compliance with the policy of the journal', Juan Antonio Añel, 04 Dec 2024
Dear authors,
Unfortunately, after checking your manuscript, it has come to our attention that it does not comply with our "Code and Data Policy".
https://www.geoscientific-model-development.net/policies/code_and_data_policy.htmlDespite the clear requirements exposed in our policy and the warning exposed by the Topical Editor before the Discussions stage, you have not shared the code used in your work, but only a few configuration files. Actually, in the repository that you have shared with the configuration you claim to have included the ROMS source code, but the corresponding directory is empty. This is disappointing. Therefore, the current situation with your manuscript is irregular. Please, publish your code in one of the appropriate repositories and reply to this comment with the relevant information (link and a permanent identifier for it (e.g. DOI)) as soon as possible, as we can not accept manuscripts in Discussions that do not comply with our policy.
Also, you must include a modified 'Code and Data Availability' section in a potentially reviewed manuscript, containing the DOI of the new repository.
Note that if you do not fix this problem as soon as possible, we will have to reject your manuscript for publication in our journal.
Juan A. Añel
Geosci. Model Dev. Executive EditorCitation: https://doi.org/10.5194/egusphere-2024-1962-CEC1 -
AC1: 'Reply on CEC1', Christopher Roach, 06 Dec 2024
Dear Dr Anel,
We thank you for bringing it to our attention that the files uploaded to the repository do not meet the current code and data policy of GMD. The files uploaded were based on one of my co-authors' understanding of the code and data policy when he submitted a paper a few years ago.
We are working to correct this oversight. However, I am currently on leave, and while one of my co-authors (Joao de Souza) will be editing the repository before then I will not be able to approve these edits and uploaded a revised version until I'm back in the office (December 23).
Dr Chris RoachCitation: https://doi.org/10.5194/egusphere-2024-1962-AC1 -
AC2: 'Reply on AC1', Christopher Roach, 23 Dec 2024
We have updated the zenodo repository with the model configuration; ROMS v4.0 source code used and analysis/validation scripts. We will submit a revised version of the manuscript with the DOI etc. for the new version of the repository ASAP.
See new DOI:
https://zenodo.org/records/14545148Citation: https://doi.org/10.5194/egusphere-2024-1962-AC2 -
CEC2: 'Reply on AC2', Juan Antonio Añel, 23 Dec 2024
Dear authors,
Many thanks for addressing this issue.
Regards,
Juan A. Añel
Geosci. Model Dev. Executive Editor
Citation: https://doi.org/10.5194/egusphere-2024-1962-CEC2
-
CEC2: 'Reply on AC2', Juan Antonio Añel, 23 Dec 2024
-
AC2: 'Reply on AC1', Christopher Roach, 23 Dec 2024
-
AC1: 'Reply on CEC1', Christopher Roach, 06 Dec 2024
-
RC1: 'Comment on egusphere-2024-1962', Anonymous Referee #1, 10 Jan 2025
The article titled “Moana Ocean Future Climate V1.0: High Resolution Marine Climate Futures For The New Zealand Region” by Roach et al., outlines a historical and future downscaling simulations of the Earth System Model configuration known as NZESM using the ROMS regional ocean model in combination with a downscaling of the NZESM atmosphere. The manuscript provides a validation of the model against a downscaled reanalysis and then proceeds to consider and document future changes. As I am not aware of a publication documenting the results of the NZESM future simulations outside of marine heat waves this downscaling analysis is particularly valuable for those wanting to understand possible change in the ocean around New Zealand. I recommend the article be accepted pending some major revisions and improvements to readability that I now discuss.
It is a bit unclear to me what the primary objectives are in documenting the new modelling framework within this manuscript. Where does the originality lie in this setup that the authors wish to highlight? It would be good to have some greater clarity about this. Considering future changes in the ocean around New Zealand is certainly achieved. But in a couple of places, the authors are clear that “the behaviour of the ocean current systems around New Zealand is sensitive to mesoscale, sub-mesoscale and high-frequency dynamics such as eddies, tides and transient responses to wind” implying that the results from the downscaling will be better than the driving NZESM model. However, there is no attempt to show this is true. The NZESM simulations are at 15km and the ROMS simulations are at 5km. Has this increased resolution improved anything? The results comparing historical simulations simply suggest that ROMS inherits its biases in temperature and salinity from NZESM. Furthermore, a key component of the modelling setup is the use of a high-resolution downscaling of the NZESM atmosphere to 12km, known as NZRCM. This then provides atmospheric forcing to ROMS at much higher resolution. This might be expected to be useful, but is this expensive computational exercise worth it? The analysis makes no attempt to answer this question as far as I can tell. An experiment that used exclusively NZESM atmospheric forcing over the domain rather than NZRCM would allow for a direct comparison and address the question of whether a high-resolution atmosphere has added value. Regardless I believe it is at a minimum necessary to demonstrate how this setup is more useful, or somehow different than NZESM, and including results from NZESM in the present figures and any appropriate new ones should allow for a straightforward comparison. Please see the attached pdf file for additional line-by-line comments.
-
RC2: 'Comment on egusphere-2024-1962', Anonymous Referee #2, 01 Mar 2025
This study reports on dynamically downscaled, ocean-climate scenario simulations (historical and projections) conducted for the ocean regions surrounding New Zealand. These efforts represent an important contribution to translating coarser resolution climate model output to regionally-relevant scales needed to understand risks posed by changing climate on marine ecosystems and resources. However, more rigorous justification and validation, and method clarity and consistency (i.e., major revisions) are needed for publication. I’ve listed broad issues below and attached a document elaborating on more specific, technical suggestions.
Justification for use of specific forcing products:
- It is not clear why the NZESM and the NZRCM (downscaled atmosphere from the NZESM) were the best choices for lateral boundary and atmospheric forcing conditions, respectively. The authors cite the outlier behavior for equilibrium climate sensitivity and transient climate response of the NZESM (Data, Lines 109-113). Also, with regards to representing the Sub-Tropical Front, the authors note “...known issues with the version of NZESM used as forcing in this study” (Abstract, Line 8). These issues would suggest that these data products are not the best tools to use with this framework.
More rigorous model validation and analysis:
- Validations of the new MOFC simulations presented in this manuscript are primarily comparison against a “well validated hindcast” (i.e., the existing, reanalysis-forced MOH hindcast simulation). Well validated does not mean the reference performs well in all aspects. There should be more comparisons against observations. Additionally, I recommend the authors indicate, when reporting discrepancies between historical MOFC and MOH, whether these departures are more or less consistent with observed ocean conditions. In other words, is MOFC on MOH or does it perform worse?
- Many of the comparisons are between means or trends that are calculated over different numbers of years, which is problematic. This can result in aliasing inter-annual variability (e.g., ENSO) and misrepresentation of the multi-decadal climate state. Ideally, the historical reference simulation for the MOFC would be the same duration as the future projection simulations (i.e., 30 years). If extending the historical simulation is not feasible, the authors should provide additional context for the shorter historical period, indicating whether the NZESM forcing product exhibited more La Niña vs. El Niño-like characteristics (if ENSO is an important consideration for conditions in this region). This would add transparency to potential biases that may arise from timeframe inconsistencies. If ENSO is not as important, please report on other modes of variability that may be relevant.
Status: closed (peer review stopped)
-
CEC1: 'Comment on egusphere-2024-1962 - No compliance with the policy of the journal', Juan Antonio Añel, 04 Dec 2024
Dear authors,
Unfortunately, after checking your manuscript, it has come to our attention that it does not comply with our "Code and Data Policy".
https://www.geoscientific-model-development.net/policies/code_and_data_policy.htmlDespite the clear requirements exposed in our policy and the warning exposed by the Topical Editor before the Discussions stage, you have not shared the code used in your work, but only a few configuration files. Actually, in the repository that you have shared with the configuration you claim to have included the ROMS source code, but the corresponding directory is empty. This is disappointing. Therefore, the current situation with your manuscript is irregular. Please, publish your code in one of the appropriate repositories and reply to this comment with the relevant information (link and a permanent identifier for it (e.g. DOI)) as soon as possible, as we can not accept manuscripts in Discussions that do not comply with our policy.
Also, you must include a modified 'Code and Data Availability' section in a potentially reviewed manuscript, containing the DOI of the new repository.
Note that if you do not fix this problem as soon as possible, we will have to reject your manuscript for publication in our journal.
Juan A. Añel
Geosci. Model Dev. Executive EditorCitation: https://doi.org/10.5194/egusphere-2024-1962-CEC1 -
AC1: 'Reply on CEC1', Christopher Roach, 06 Dec 2024
Dear Dr Anel,
We thank you for bringing it to our attention that the files uploaded to the repository do not meet the current code and data policy of GMD. The files uploaded were based on one of my co-authors' understanding of the code and data policy when he submitted a paper a few years ago.
We are working to correct this oversight. However, I am currently on leave, and while one of my co-authors (Joao de Souza) will be editing the repository before then I will not be able to approve these edits and uploaded a revised version until I'm back in the office (December 23).
Dr Chris RoachCitation: https://doi.org/10.5194/egusphere-2024-1962-AC1 -
AC2: 'Reply on AC1', Christopher Roach, 23 Dec 2024
We have updated the zenodo repository with the model configuration; ROMS v4.0 source code used and analysis/validation scripts. We will submit a revised version of the manuscript with the DOI etc. for the new version of the repository ASAP.
See new DOI:
https://zenodo.org/records/14545148Citation: https://doi.org/10.5194/egusphere-2024-1962-AC2 -
CEC2: 'Reply on AC2', Juan Antonio Añel, 23 Dec 2024
Dear authors,
Many thanks for addressing this issue.
Regards,
Juan A. Añel
Geosci. Model Dev. Executive Editor
Citation: https://doi.org/10.5194/egusphere-2024-1962-CEC2
-
CEC2: 'Reply on AC2', Juan Antonio Añel, 23 Dec 2024
-
AC2: 'Reply on AC1', Christopher Roach, 23 Dec 2024
-
AC1: 'Reply on CEC1', Christopher Roach, 06 Dec 2024
-
RC1: 'Comment on egusphere-2024-1962', Anonymous Referee #1, 10 Jan 2025
The article titled “Moana Ocean Future Climate V1.0: High Resolution Marine Climate Futures For The New Zealand Region” by Roach et al., outlines a historical and future downscaling simulations of the Earth System Model configuration known as NZESM using the ROMS regional ocean model in combination with a downscaling of the NZESM atmosphere. The manuscript provides a validation of the model against a downscaled reanalysis and then proceeds to consider and document future changes. As I am not aware of a publication documenting the results of the NZESM future simulations outside of marine heat waves this downscaling analysis is particularly valuable for those wanting to understand possible change in the ocean around New Zealand. I recommend the article be accepted pending some major revisions and improvements to readability that I now discuss.
It is a bit unclear to me what the primary objectives are in documenting the new modelling framework within this manuscript. Where does the originality lie in this setup that the authors wish to highlight? It would be good to have some greater clarity about this. Considering future changes in the ocean around New Zealand is certainly achieved. But in a couple of places, the authors are clear that “the behaviour of the ocean current systems around New Zealand is sensitive to mesoscale, sub-mesoscale and high-frequency dynamics such as eddies, tides and transient responses to wind” implying that the results from the downscaling will be better than the driving NZESM model. However, there is no attempt to show this is true. The NZESM simulations are at 15km and the ROMS simulations are at 5km. Has this increased resolution improved anything? The results comparing historical simulations simply suggest that ROMS inherits its biases in temperature and salinity from NZESM. Furthermore, a key component of the modelling setup is the use of a high-resolution downscaling of the NZESM atmosphere to 12km, known as NZRCM. This then provides atmospheric forcing to ROMS at much higher resolution. This might be expected to be useful, but is this expensive computational exercise worth it? The analysis makes no attempt to answer this question as far as I can tell. An experiment that used exclusively NZESM atmospheric forcing over the domain rather than NZRCM would allow for a direct comparison and address the question of whether a high-resolution atmosphere has added value. Regardless I believe it is at a minimum necessary to demonstrate how this setup is more useful, or somehow different than NZESM, and including results from NZESM in the present figures and any appropriate new ones should allow for a straightforward comparison. Please see the attached pdf file for additional line-by-line comments.
-
RC2: 'Comment on egusphere-2024-1962', Anonymous Referee #2, 01 Mar 2025
This study reports on dynamically downscaled, ocean-climate scenario simulations (historical and projections) conducted for the ocean regions surrounding New Zealand. These efforts represent an important contribution to translating coarser resolution climate model output to regionally-relevant scales needed to understand risks posed by changing climate on marine ecosystems and resources. However, more rigorous justification and validation, and method clarity and consistency (i.e., major revisions) are needed for publication. I’ve listed broad issues below and attached a document elaborating on more specific, technical suggestions.
Justification for use of specific forcing products:
- It is not clear why the NZESM and the NZRCM (downscaled atmosphere from the NZESM) were the best choices for lateral boundary and atmospheric forcing conditions, respectively. The authors cite the outlier behavior for equilibrium climate sensitivity and transient climate response of the NZESM (Data, Lines 109-113). Also, with regards to representing the Sub-Tropical Front, the authors note “...known issues with the version of NZESM used as forcing in this study” (Abstract, Line 8). These issues would suggest that these data products are not the best tools to use with this framework.
More rigorous model validation and analysis:
- Validations of the new MOFC simulations presented in this manuscript are primarily comparison against a “well validated hindcast” (i.e., the existing, reanalysis-forced MOH hindcast simulation). Well validated does not mean the reference performs well in all aspects. There should be more comparisons against observations. Additionally, I recommend the authors indicate, when reporting discrepancies between historical MOFC and MOH, whether these departures are more or less consistent with observed ocean conditions. In other words, is MOFC on MOH or does it perform worse?
- Many of the comparisons are between means or trends that are calculated over different numbers of years, which is problematic. This can result in aliasing inter-annual variability (e.g., ENSO) and misrepresentation of the multi-decadal climate state. Ideally, the historical reference simulation for the MOFC would be the same duration as the future projection simulations (i.e., 30 years). If extending the historical simulation is not feasible, the authors should provide additional context for the shorter historical period, indicating whether the NZESM forcing product exhibited more La Niña vs. El Niño-like characteristics (if ENSO is an important consideration for conditions in this region). This would add transparency to potential biases that may arise from timeframe inconsistencies. If ENSO is not as important, please report on other modes of variability that may be relevant.
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