the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 20 Sep 2023
Biophysical coupling of seasonal chlorophyll-a bloom variations and phytoplankton assemblages across the Peninsula Front in the Bransfield Strait
Abstract. This study investigates the spatio-temporal variations of the chl-a blooms in the Bransfield Strait (BS) at a climatological scale (1998–2018). We propose that a suitable monitoring of these blooms can be achieved through remotely-sensed observations only if the Bransfield Strait is divided following the Peninsula Front, which ultimately influence the phytoplankton assemblage. Our analysis is based on characterizing climatological fields of Sea Surface Temperature (SST), air temperature, Sea-Ice Coverage (SIC), chl-a concentrations and wind stress, guided by synoptic novel and historical in situ observations which reveal two niches for phytoplankton assemblage: the Transitional Bellingshausen Water (TBW) and Transitional Weddell Water (TWW) pools. The TBW pool features stratified, less saline, warmer waters with shallow mixed layers, while the TWW pool features well-mixed, colder, and saltier waters. We identify that the 0.6 ºC isotherm corresponds to the climatological Peninsula Front location, effectively dividing the Bransfield Strait in two different scenarios. Furthermore, the 0.5 mg m−3 chl-a isoline aligns well with the 0.6 ºC isotherm, serving as a threshold for chl-a blooms of highest concentrations around the South Shetland Islands. These thresholds enable for the first time the monthly climatological description of the two blooms developing in BS at both sides of the Peninsula Front. We think this approach underscores the potential of combining SST and chl-a data to monitor the year-to-year interplay of the chl-a blooms occurring in the TBW and TWW pools contoured by the Peninsula Front.
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Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
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Preprint
(4813 KB)
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
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- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
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RC1: 'Comment on egusphere-2023-2051', Anonymous Referee #1, 03 Nov 2023
This manuscript presents the results of the study of spatio-temporal variations of Chl-a blooms in the Bransfield Strait at a climatological scale (1998–2018). An original technique, based on the results of remote sensing and hydro-meteorological data obtained in situ, is proposed for a suitable monitoring of these blooms.
The material is well structured and clearly presented.
In my opinion, the manuscript should be accepted to publication, taking into account the minor concers, stated below:
Figure 1: The indices (a) and (b), marked in the figure’s caption are absent in the images.
Line 129 -130: These sentences should be deleted.
Figures 2, 3 ,4: It’s practically impossible to distinguish the colours of the stations in the map on the subfigure on right below that does not allow identification of the corresponding T,S curves on the subfigure above.
Line 542-543 should be combined.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC1 -
CC1: 'Reply on RC1', Marta Veny, 03 Nov 2023
Dear Referee #1,
Thank you for the time and effort dedicated to providing feedback about our research work. We appreciate your valuable input regarding the figures in question. We will apply the suggested changes to improve our manuscript.
We believe these changes adequately address your concerns. If you have any further comments or suggestions, please don't hesitate to let us know.
Best regards,
MartaCitation: https://doi.org/10.5194/egusphere-2023-2051-CC1 -
AC4: 'Reply on RC1', Borja Aguiar González, 05 Jan 2024
Dear Reviewer #1,
Thank you very much for your comments. As my colleague mentioned, we have taken them all into account in our revised version.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC4 -
AC5: 'Reply on RC1', Borja Aguiar González, 05 Jan 2024
Dear Reviewer #1,
We appreciate the careful reading of our work and constructive feedback, which has contributed to improving our manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC5
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CC1: 'Reply on RC1', Marta Veny, 03 Nov 2023
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RC2: 'Comment on egusphere-2023-2051', Anonymous Referee #2, 25 Dec 2023
The study presented in the abstract provides valuable insights into the spatio-temporal variations of chl-a blooms in the Bransfield Strait over a climatological scale. The researchers tackle an important problem of monitoring these blooms using remotely-sensed observations and propose a novel approach by dividing the Bransfield Strait based on the Peninsula Front. This approach is supported by the characterization of various climatological fields and guided by both novel and historical in situ observations. One of the strengths of this study is the identification of two distinct phytoplankton assemblage niches: the Transitional Bellingshausen Water (TBW) and Transitional Weddell Water (TWW) pools. By analyzing the characteristics of these pools, such as water temperature, salinity, and mixing, the study provides a comprehensive understanding of the environmental factors influencing chl-a blooms in the Bransfield Strait. The monthly climatological description of the two blooms occurring on both sides of the Peninsula Front enhances our understanding of the interplay between chl-a blooms in the TBW and TWW pools.
The integration of SST and chl-a data for monitoring chl-a blooms is another essential aspect of this study. By combining these datasets, researchers can track the year-to-year variations of chl-a blooms in the Bransfield Strait and gain insights into the long-term dynamics of phytoplankton assemblages. Similar approach has been applied in some of the coastal ocean that is useful to reveal the dependence of chl-a to dynamical factors. However, the authors failed to calculate the wind in correct approach that can lead to significant error in estimation.
In conclusion, the study offers valuable contributions to the understanding of spatio-temporal variations of chl-a blooms in the Bransfield Strait. The proposed approach of dividing the strait based on the Peninsula Front, the identification of distinct phytoplankton assemblage niches, and the integration of SST and chl-a data for monitoring are all commendable. This research has the potential to enhance our knowledge of chl-a blooms in the region and contribute to the field of marine ecology and remote sensing. However, there are some unclear descriptions, even errors, as well as careless in writing; thus, a major revision is necessary to improve the quality.
Major comments:
- A major error is the calculation for wind stress shown in equation (1). The zonal and meridional wind stress should be calculated respectively for both wind speed and wind vector. However, the authors applied the wind speed as the total wind speed. This is definitely resulting in significant over estimation of wind stress.
- The major feature in Figure 1(b) is less helpful and can be combined into Figure 1(a). While the mean SST or chl-a (contour) can be shown instead for readers to understand the major patterns in the study region.
- The front is generally identified using the SST gradient and the frontal probability is usually applied for identifying the location of fronts. The identified frontal distribution from satellite observation can be compared with the cruise observation. The authors should elaborate more discussion related with front dynamics in current study.
- The same approach is actually applied by Yu et al. (2019, JMS) for underscoring the dependence between chl-a and other factors. Thus, the creativity is not relying on the intercorrelation among different parameters, unless the difference between current and former study is highlighted.
- Many careless in the writing, such as forgetting to upper case the unit of chlorophyll, the reference (Sangrà et al. (2017)), chl-a and SST among others should be used after defining the abbreviation. The authors should double check the text throughout the manuscript.
- The governing dynamics should be discussed with observational evident, though only two cruises were available. Additional satellite observations or literature result can be applied as supplementary proof for the underlying dynamics.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC2 -
AC1: 'Reply on RC2', Borja Aguiar González, 29 Dec 2023
Dear Reviewer #2,
Thank you for the careful reading of our work and constructive feedback, which has contributed to improving our manuscript. Please see our response to your suggestions and comments added as a supplement in pdf format. This includes an updated version of Figure 1, as requested.-
RC3: 'Reply on AC1', Anonymous Referee #2, 01 Jan 2024
Publisher’s note: the content of this comment as well as the subsequent exchange were removed on 9 January 2024 by the OS executive editors as they did not meet the expectations of the discussion to provide objective and constructive comments on the manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC3 -
AC2: 'Reply on RC3', Borja Aguiar González, 02 Jan 2024
Following the most recent post of reviewer #2, it is clear to us that there is an issue calling for further attention regarding the computation of wind stress. We address this issue newly in the attached document.
If reviewer #2 still thinks we are making a mistake, we would appreciate he/she provides at least one reference from the literature supporting the equations he/she uses and proving that a mistake in our equations exists.
In the attached document, we demonstrate how to obtain correctly the equations we use. To do so, we make use (for simplicity) of the same terminology and symbols that reviewer #2 uses in the PDF he/she attaches to his/her response.
Furthermore, we support the equations we use with a list of references from the literature (also indicated in the attached document).
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RC4: 'Reply on AC2', Anonymous Referee #2, 03 Jan 2024
Publisher’s note: the content of this comment as well as the subsequent exchange were removed on 9 January 2024 by the OS executive editors as they did not meet the expectations of the discussion to provide objective and constructive comments on the manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC4 -
AC3: 'Reply on RC4', Borja Aguiar González, 05 Jan 2024
We would like to express our gratitude to the editor for his meticulous editorial work, contrasting diligently previous arguments in this Discussion Forum with external physical oceanographers. Also, we are glad to learn that the two external scientists confirmed the procedure and equations we followed are correct, and the equations posed by the reviewer #2 are not. We respect the subsequent silence from reviewer #2 and understand that this may be a challenging situation for him/her. We encourage him/her to reflect on this experience and consider adopting a humbler approach in future arguments.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC3
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AC3: 'Reply on RC4', Borja Aguiar González, 05 Jan 2024
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RC4: 'Reply on AC2', Anonymous Referee #2, 03 Jan 2024
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AC2: 'Reply on RC3', Borja Aguiar González, 02 Jan 2024
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RC3: 'Reply on AC1', Anonymous Referee #2, 01 Jan 2024
-
CEC1: 'Comment on egusphere-2023-2051', Bernadette Sloyan, 10 Jan 2024
The co-editors-in-chief intervened to remove anonymous referee comments that contravened the OS principles for the interactive public discussion namely that "comments that are not of substantial nature or of direct relevance to the issues raised in the manuscript in discussion or which contain personal insults" are not acceptable and will be censored.
Citation: https://doi.org/10.5194/egusphere-2023-2051-CEC1
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2023-2051', Anonymous Referee #1, 03 Nov 2023
This manuscript presents the results of the study of spatio-temporal variations of Chl-a blooms in the Bransfield Strait at a climatological scale (1998–2018). An original technique, based on the results of remote sensing and hydro-meteorological data obtained in situ, is proposed for a suitable monitoring of these blooms.
The material is well structured and clearly presented.
In my opinion, the manuscript should be accepted to publication, taking into account the minor concers, stated below:
Figure 1: The indices (a) and (b), marked in the figure’s caption are absent in the images.
Line 129 -130: These sentences should be deleted.
Figures 2, 3 ,4: It’s practically impossible to distinguish the colours of the stations in the map on the subfigure on right below that does not allow identification of the corresponding T,S curves on the subfigure above.
Line 542-543 should be combined.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC1 -
CC1: 'Reply on RC1', Marta Veny, 03 Nov 2023
Dear Referee #1,
Thank you for the time and effort dedicated to providing feedback about our research work. We appreciate your valuable input regarding the figures in question. We will apply the suggested changes to improve our manuscript.
We believe these changes adequately address your concerns. If you have any further comments or suggestions, please don't hesitate to let us know.
Best regards,
MartaCitation: https://doi.org/10.5194/egusphere-2023-2051-CC1 -
AC4: 'Reply on RC1', Borja Aguiar González, 05 Jan 2024
Dear Reviewer #1,
Thank you very much for your comments. As my colleague mentioned, we have taken them all into account in our revised version.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC4 -
AC5: 'Reply on RC1', Borja Aguiar González, 05 Jan 2024
Dear Reviewer #1,
We appreciate the careful reading of our work and constructive feedback, which has contributed to improving our manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC5
-
CC1: 'Reply on RC1', Marta Veny, 03 Nov 2023
-
RC2: 'Comment on egusphere-2023-2051', Anonymous Referee #2, 25 Dec 2023
The study presented in the abstract provides valuable insights into the spatio-temporal variations of chl-a blooms in the Bransfield Strait over a climatological scale. The researchers tackle an important problem of monitoring these blooms using remotely-sensed observations and propose a novel approach by dividing the Bransfield Strait based on the Peninsula Front. This approach is supported by the characterization of various climatological fields and guided by both novel and historical in situ observations. One of the strengths of this study is the identification of two distinct phytoplankton assemblage niches: the Transitional Bellingshausen Water (TBW) and Transitional Weddell Water (TWW) pools. By analyzing the characteristics of these pools, such as water temperature, salinity, and mixing, the study provides a comprehensive understanding of the environmental factors influencing chl-a blooms in the Bransfield Strait. The monthly climatological description of the two blooms occurring on both sides of the Peninsula Front enhances our understanding of the interplay between chl-a blooms in the TBW and TWW pools.
The integration of SST and chl-a data for monitoring chl-a blooms is another essential aspect of this study. By combining these datasets, researchers can track the year-to-year variations of chl-a blooms in the Bransfield Strait and gain insights into the long-term dynamics of phytoplankton assemblages. Similar approach has been applied in some of the coastal ocean that is useful to reveal the dependence of chl-a to dynamical factors. However, the authors failed to calculate the wind in correct approach that can lead to significant error in estimation.
In conclusion, the study offers valuable contributions to the understanding of spatio-temporal variations of chl-a blooms in the Bransfield Strait. The proposed approach of dividing the strait based on the Peninsula Front, the identification of distinct phytoplankton assemblage niches, and the integration of SST and chl-a data for monitoring are all commendable. This research has the potential to enhance our knowledge of chl-a blooms in the region and contribute to the field of marine ecology and remote sensing. However, there are some unclear descriptions, even errors, as well as careless in writing; thus, a major revision is necessary to improve the quality.
Major comments:
- A major error is the calculation for wind stress shown in equation (1). The zonal and meridional wind stress should be calculated respectively for both wind speed and wind vector. However, the authors applied the wind speed as the total wind speed. This is definitely resulting in significant over estimation of wind stress.
- The major feature in Figure 1(b) is less helpful and can be combined into Figure 1(a). While the mean SST or chl-a (contour) can be shown instead for readers to understand the major patterns in the study region.
- The front is generally identified using the SST gradient and the frontal probability is usually applied for identifying the location of fronts. The identified frontal distribution from satellite observation can be compared with the cruise observation. The authors should elaborate more discussion related with front dynamics in current study.
- The same approach is actually applied by Yu et al. (2019, JMS) for underscoring the dependence between chl-a and other factors. Thus, the creativity is not relying on the intercorrelation among different parameters, unless the difference between current and former study is highlighted.
- Many careless in the writing, such as forgetting to upper case the unit of chlorophyll, the reference (Sangrà et al. (2017)), chl-a and SST among others should be used after defining the abbreviation. The authors should double check the text throughout the manuscript.
- The governing dynamics should be discussed with observational evident, though only two cruises were available. Additional satellite observations or literature result can be applied as supplementary proof for the underlying dynamics.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC2 -
AC1: 'Reply on RC2', Borja Aguiar González, 29 Dec 2023
Dear Reviewer #2,
Thank you for the careful reading of our work and constructive feedback, which has contributed to improving our manuscript. Please see our response to your suggestions and comments added as a supplement in pdf format. This includes an updated version of Figure 1, as requested.-
RC3: 'Reply on AC1', Anonymous Referee #2, 01 Jan 2024
Publisher’s note: the content of this comment as well as the subsequent exchange were removed on 9 January 2024 by the OS executive editors as they did not meet the expectations of the discussion to provide objective and constructive comments on the manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC3 -
AC2: 'Reply on RC3', Borja Aguiar González, 02 Jan 2024
Following the most recent post of reviewer #2, it is clear to us that there is an issue calling for further attention regarding the computation of wind stress. We address this issue newly in the attached document.
If reviewer #2 still thinks we are making a mistake, we would appreciate he/she provides at least one reference from the literature supporting the equations he/she uses and proving that a mistake in our equations exists.
In the attached document, we demonstrate how to obtain correctly the equations we use. To do so, we make use (for simplicity) of the same terminology and symbols that reviewer #2 uses in the PDF he/she attaches to his/her response.
Furthermore, we support the equations we use with a list of references from the literature (also indicated in the attached document).
-
RC4: 'Reply on AC2', Anonymous Referee #2, 03 Jan 2024
Publisher’s note: the content of this comment as well as the subsequent exchange were removed on 9 January 2024 by the OS executive editors as they did not meet the expectations of the discussion to provide objective and constructive comments on the manuscript.
Citation: https://doi.org/10.5194/egusphere-2023-2051-RC4 -
AC3: 'Reply on RC4', Borja Aguiar González, 05 Jan 2024
We would like to express our gratitude to the editor for his meticulous editorial work, contrasting diligently previous arguments in this Discussion Forum with external physical oceanographers. Also, we are glad to learn that the two external scientists confirmed the procedure and equations we followed are correct, and the equations posed by the reviewer #2 are not. We respect the subsequent silence from reviewer #2 and understand that this may be a challenging situation for him/her. We encourage him/her to reflect on this experience and consider adopting a humbler approach in future arguments.
Citation: https://doi.org/10.5194/egusphere-2023-2051-AC3
-
AC3: 'Reply on RC4', Borja Aguiar González, 05 Jan 2024
-
RC4: 'Reply on AC2', Anonymous Referee #2, 03 Jan 2024
-
AC2: 'Reply on RC3', Borja Aguiar González, 02 Jan 2024
-
RC3: 'Reply on AC1', Anonymous Referee #2, 01 Jan 2024
-
CEC1: 'Comment on egusphere-2023-2051', Bernadette Sloyan, 10 Jan 2024
The co-editors-in-chief intervened to remove anonymous referee comments that contravened the OS principles for the interactive public discussion namely that "comments that are not of substantial nature or of direct relevance to the issues raised in the manuscript in discussion or which contain personal insults" are not acceptable and will be censored.
Citation: https://doi.org/10.5194/egusphere-2023-2051-CEC1
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Marta Veny
Borja Aguiar-González
Ángeles Marrero-Díaz
Tania Pereira-Vázquez
Ángel Rodríguez-Santana
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(4813 KB) - Metadata XML