Global Climate Pattern Impacts on Long-Term Olive Yields in Northwestern Africa: Case from Souss-Massa Region

Round 1

Reviewer 1 Report

The proposed manuscript “Global climate patterns impacts on long-term Olive yields in Northwestern Africa: Case from Souss-Massa region” is focused on an important problem for regions with strong large-scale climate oscillation influences. Ocean influences on climate variability and its effects on yield, concerning olive plantations in southern Morocco is always important to be further explored. In the current work, the influence of climate phenomena ENSO, IOD, NAO and PDO on olive yield variability is studied, applying statistical analyses of lagged Spearman’s correlation and cross-wavelet analysis using a long-term dataset 1973-2014. The climate oscillations are expressed by using standard applied indexes. The objective of this study is within the scope of the Sustainability journal and methodology applied is acceptable. However, the paper is suffering from a lack of insightful and comprehensive analyses.

Results indicate for statistically significant decreasing trend in yield during the studied period and confirm relations between olive yield and different climate-oscillation indexes. In general, based on contemporary statistical approach the study confirms already established effects of climate patterns on yield for regions with a definite ocean influence on climate like Morocco.

The main recommendations for improving the proposed manuscript are:

• To clarifying what is the new in this manuscript, what is already confirmed in the literature speaking about climate pattern-yield relations?
• El Niño and La Niña warm and cool phases of a recurring climate pattern can shift back and forth irregularly every two to seven years, and each phase triggers predictable disruptions of temperature, precipitation, and winds. In the current work nowhere meteorological nature of these phenomena and their effects are analyzed.
• Results are presented schematically; Discussion is needed to stress on the mechanism of large-scale climate oscillations –yield relations.

To be considered for publishing, the manuscript must be improved after major revision.

I would suggest the following specific recommendations:

1. The dot on the end of the title must be removed.
2. Keywords are not well selected; it is not necessary keywords to repeat the title of the manuscript. For example: ‘climate patterns’ might be replaced with ‘climate oscillation’; ‘impact’ is not necessary,’ long-term’ may be also avoided, etc.
3. ‘Introduction’ is not enough informative about the status of the problem and what will be the add value of the current work? More literature evidences would be relevant in terms of the meaning of ‘climate patterns’ and how yield-oscillation relations have been studied by other authors for the region of NW Africa.
4. On Ln 57, the authors are speaking about climate change effect on degradation of water resources; terms climate variability and trends would pass better for the situation.
5. Figure 1 is not introduced in the text; the study area should be described in the text not only in the caption of the figure with some clear explanations.
6. Ln 95, in ‘Methods’ paragraph the authors say ‘Climatic patterns’ are non-stationary processes……’ and go directly to the description of statistical methods applied in the study. But the global climate system contains many processes; climate patterns might be characterized for example by the climate classification of Köppen. Nowhere in the text the understanding what does it mean ‘climate pattern’ for the purposes of the current study is introduced.
7. Ln 111, there is a small typos; it should be ‘phenological’.
8. Ln 115, the paragraph 2.3.2. is titled ‘Climate pattern’ but actually it introduces the indexes applied for characterizing climate oscillations; it would be relevant to adapt the title and here to reflect the recommendations from p. 6.
9. Ln 136, links indicating the meaning and calculation of different climate oscillation indexes are introduced. Please explain how you infer the indexes values, calculating or use the archive information from the sites. Nowhere meteorological information used by the authors to calculate the indexes (in case of indexes calculation), time series, etc. is described. Meteorological information required for indexes calculation should be introduced.
10. Results are presented very schematic, there is no analytical explanation of the figures in the text:

• Explanation of Figures in the text are almost missing and include only brief statements; the reader should analyze the graphs alone;
• For Figure 2 and 3 captions you can add the region concerned;
• Authors emphasize on the statistical relations yield – indexes (Table 1) but nowhere it is explained which are the years with corresponding climatic extremes.
• About the title of Table 1, the values in bold indicating 95% statistical significance are not well recognized; you can select another indication for these values. It will be relevant some explanation and comments of correlations to be included in the text.
• There is no relevant analyses of indexes (in terms of their meaning as related to SST anomalies, sea level presser etc.) with the corresponding effects, e.g. of precipitation deficit or temperature anomalies, drought occurrence as a possible reason for yield decline. Actually meteorology of climate patterns is missing.

11. About Discussion paragraph, again analytical analyses of the results is missing, comments are more or less mechanically added:

• Ln 215, Authors say ‘The main climate variables relevant at the seasonal timescale in physiological development of the Olive fruits are principally rainfall and temperature. In particular, Olive flowering dates depend strongly on spring temperatures [17].’ But nowhere in the text the meteorology of climate oscillations and their influence on yield (in terms e.g. of temperature, precipitation) is evaluated?
• Ln 221, Authors say ‘The results obtained here are in accordance with previous works treating the influence of the ENSO and the NAO on Olive yields in Turkey [45] and in Spain [46], where……’. It is relevant to know if this is studied before for NW Africa?

12. Ln 239, Authors state ‘The importance of the results of this work emphasize from the fact that the data used are observed yields while number of studies relies on simulated yield data [49].’ Using yield data from measurements is a positive feature of the study but it will be valuable to confirm your statement discussing some results of similar studies using model yield data.
13. It is noteworthy in the Discussion paragraph to present some analyses about the physical mechanism of climate oscillation influences on temperature/precipitation-drought-yield relations; there are contemporary literature evidences about these complicated phenomena, e.g.:

• First, many studies have examined the connection between ocean surface temperature changes and conterminous droughts. However, remote effects of large-scale land surface temperature variability, over shorter but still considerable distances on regional droughts have been largely ignored. Xue et al. (2018) study combines two types of evidence to address these effects. You may use the publication:

Xue, Y., Diallo, I., Li, W., David Neelin, J., Chu, P. C., Vasic, R., et al. (2018). Spring land surface and subsurface temperature anomalies and subsequent downstream late spring-summer droughts/floods in North America and East Asia. Journal of Geophysical Research: Atmospheres, 123, 5001– 5019. https://doi.org/10.1029/2017JD028246

• Second, the physical mechanism of the relation between surface temperature and drought is illustrated in following publications (as example):

Stoyanova, J.; Georgiev, C.; Neytchev, P.; Kulishev, A. Spatial-Temporal Variability of Land Surface Dry Anomalies in Climatic Aspect: Biogeophysical Insight by Meteosat Observations and SVAT Modeling. Atmosphere 2019, 10, 636.

Stoyanova, S. J., Georgiev, C. G, Barroso, C. (2012): MSG Land Surface Temperature product as a biogeophysical diagnostic parameter of terrestrial water status. 2012 EUMETSAT Meteorological Satellite Conference, 3-7 September, Sopot, Poland. https://www.eumetsat.int/website/home/News/ConferencesandEvents/DAT_2035484.html?lang=EN

• Third, the surface temperature and soil moisture are strongly influencing the atmosphere temperature environment during heat wave episodes that from the other hand affect yield, e.g. see in:

Stoyanova, J.; Georgiev, C.; Neytchev, P.; Using land surface analyses to assess weather extremes: Heat waves and drought effects. In: 5th SALGEE Workshop, 18 - 20 September, Yerevan, Armenia ‘MSG Land Surface Applications: Heat waves, Drought Hazard and Fire Monitoring’, EUMETSAT

              https://training.eumetsat.int/mod/folder/view.php?id=12706

Marc St´efanon, Philippe Drobinski, Fabio D’Andrea, Nathalie De Noblet-Ducoudr´ e. Effects of interactive vegetation phenology on the 2003 summer heat waves. Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2012, 117 (24), pp.D24103. <10.1029/2012JD018187>.

Author Response

Response to Reviewer 1 Comments

Point 1: The dot on the end of the title must be removed.

Response 1: The dot on the end of the title is removed.

Point 2: Keywords are not well selected; it is not necessary keywords to repeat the title of the manuscript. For example: ‘climate patterns’ might be replaced with ‘climate oscillation’; ‘impact’ is not necessary,’ long-term’ may be also avoided, etc.

Response 2: Keywords replaced.

Point 3: ‘Introduction’ is not enough informative about the status of the problem and what will be the add value of the current work? More literature evidences would be relevant in terms of the meaning of ‘climate patterns’ and how yield-oscillation relations have been studied by other authors for the region of NW Africa.

Response 3: Amendments added at lines 82-84.

Point 4: On Ln 57, the authors are speaking about climate change effect on degradation of water resources; terms climate variability and trends would pass better for the situation.

Response 4: Amendments added at lines 71-72.

Point 5: Figure 1 is not introduced in the text; the study area should be described in the text not only in the caption of the figure with some clear explanations.

Response 5: Amendments added at lines 87-91.

Point 6: Ln 95, in ‘Methods’ paragraph the authors say ‘Climatic patterns’ are non-stationary processes……’ and go directly to the description of statistical methods applied in the study. But the global climate system contains many processes; climate patterns might be characterized for example by the climate classification of Köppen. Nowhere in the text the understanding what does it mean ‘climate pattern’ for the purposes of the current study is introduced.

Response 6: climate pattern is replaced by climate oscillation to be clearer.

Point 7: Ln 111, there is a small typos; it should be ‘phenological’.

Response 7: Amendments added at line 122.

Point 8: Ln 115, the paragraph 2.3.2. is titled ‘Climate pattern’ but actually it introduces the indexes applied for characterizing climate oscillations; it would be relevant to adapt the title and here to reflect the recommendations from p. 6.

Response 8: climate pattern are replaced by climate oscillations

Point 9: Ln 136, links indicating the meaning and calculation of different climate oscillation indexes are introduced. Please explain how you infer the indexes values, calculating or use the archive information from the sites. Nowhere meteorological information used by the authors to calculate the indexes (in case of indexes calculation), time series, etc. is described. Meteorological information required for indexes calculation should be introduced

Response 9: The time series used in this work are obtained as 3-months averages to represent meteorological seasons (lines 146-147).

Point 10.1 Explanation of Figures in the text are almost missing and include only brief statements; the reader should analyze the graphs alone;

Response 10.1: Amendments added line 165.

Point 10.2 :For Figure 2 and 3 captions you can add the region concerned;

Response 10.2: Amendments added in Figure 2 and 3.

Point 10.3 Authors emphasize on the statistical relations yield – indexes (Table 1) but nowhere it is explained which are the years with corresponding climatic extremes.

Response 10.3: Amendments added in lines 214-215.

Point 10.4 About the title of Table 1, the values in bold indicating 95% statistical significance are not well recognized; you can select another indication for these values. It will be relevant some explanation and comments of correlations to be included in the text.

Response 10.4: Amendment added in table 1 caption.

Point 10.5 There is no relevant analyses of indexes (in terms of their meaning as related to SST anomalies, sea level presser etc.) with the corresponding effects, e.g. of precipitation deficit or temperature anomalies, drought occurrence as a possible reason for yield decline. Actually meteorology of climate patterns is missing.

Response 10.5: the lines 259-261 are pointing to the corresponding effect on temperature.

Point 11.1 :Ln 215, Authors say ‘The main climate variables relevant at the seasonal timescale in physiological development of the Olive fruits are principally rainfall and temperature. In particular, Olive flowering dates depend strongly on spring temperatures [17].’ But nowhere in the text the meteorology of climate oscillations and their influence on yield (in terms e.g. of temperature, precipitation) is evaluated?

Response 11.1: The pending question might be more clearly developed in further works.

Point 11.2 Ln 221, Authors say ‘The results obtained here are in accordance with previous works treating the influence of the ENSO and the NAO on Olive yields in Turkey [45] and in Spain [46], where……’. It is relevant to know if this is studied before for NW Africa?

Response 11.2: line 82-83 no previous work treating olive yield/climate oscillation in the studied region are found.

Point 12 Ln 239, Authors state ‘The importance of the results of this work emphasize from the fact that the data used are observed yields while number of studies relies on simulated yield data [49].’ Using yield data from measurements is a positive feature of the study but it will be valuable to confirm your statement discussing some results of similar studies using model yield data.

Response 12: Similar studied investigating model Olive yields data was not found to compare the results

Point 13 It is noteworthy in the Discussion paragraph to present some analyses about the physical mechanism of climate oscillation influences on temperature/precipitation-drought-yield relations; there are contemporary literature evidences about these complicated phenomena, e.g.:

• First, many studies have examined the connection between ocean surface temperature changes and conterminous droughts. However, remote effects of large-scale land surface temperature variability, over shorter but still considerable distances on regional droughts have been largely ignored. Xue et al. (2018) study combines two types of evidence to address these effects. You may use the publication:

Xue, Y., Diallo, I., Li, W., David Neelin, J., Chu, P. C., Vasic, R., et al. (2018). Spring land surface and subsurface temperature anomalies and subsequent downstream late spring-summer droughts/floods in North America and East Asia. Journal of Geophysical Research: Atmospheres, 123, 5001– 5019. https://doi.org/10.1029/2017JD028246

• Second, the physical mechanism of the relation between surface temperature and drought is illustrated in following publications (as example):

Stoyanova, J.; Georgiev, C.; Neytchev, P.; Kulishev, A. Spatial-Temporal Variability of Land Surface Dry Anomalies in Climatic Aspect: Biogeophysical Insight by Meteosat Observations and SVAT Modeling. Atmosphere 2019, 10, 636.

Stoyanova, S. J., Georgiev, C. G, Barroso, C. (2012): MSG Land Surface Temperature product as a biogeophysical diagnostic parameter of terrestrial water status. 2012 EUMETSAT Meteorological Satellite Conference, 3-7 September, Sopot, Poland. https://www.eumetsat.int/website/home/News/ConferencesandEvents/DAT_2035484.html?lang=EN

• Third, the surface temperature and soil moisture are strongly influencing the atmosphere temperature environment during heat wave episodes that from the other hand affect yield, e.g. see in:

Stoyanova, J.; Georgiev, C.; Neytchev, P.; Using land surface analyses to assess weather extremes: Heat waves and drought effects. In: 5th SALGEE Workshop, 18 - 20 September, Yerevan, Armenia ‘MSG Land Surface Applications: Heat waves, Drought Hazard and Fire Monitoring’, EUMETSAT

            https://training.eumetsat.int/mod/folder/view.php?id=12706

Marc St´efanon, Philippe Drobinski, Fabio D’Andrea, Nathalie De Noblet-Ducoudr´ e. Effects of interactive vegetation phenology on the 2003 summer heat waves. Journal of Geophysical Research: Atmospheres, American Geophysical Union, 2012, 117 (24), pp.D24103. <10.1029/2012JD018187>.

Response 13: A paragraph is added in Discussion section 255-265.

Author Response File: Author Response.pdf

Reviewer 2 Report

Very interesting work and full of further future insights. I invite you to describe in more detail, complete with equations, the statistical methodologies used.

Author Response

Response to Reviewer 2 Comments

Point 1: Very interesting work and full of further future insights. I invite you to describe in more detail, complete with equations, the statistical methodologies used.

Response 1 Complete equations are found in the cited reference to avoid redundancy.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript presents several flaws. Firstly, it is not clear if there is any substantial contribution from this work. The literature review was not properly addressed. It seems paper does not have a clear objective and different kind of analysis have been done which cause to make difficulty to have a specific direction. In addition to the problem in the objective and methodology section, the interpretation of the results is not clear. The Mann-Kendall test does not use properly, and it recommend that authors review the theory of Mann-Kendall test and have an appropriate use of the trend analysis test. In addition, the authors have failed to clearly explain the importance of this work, as well as to point out which is the substantial contribution of this paper. I suggest adding more analysis to show the uniqueness of your study. In general, it is not clear either the relevance, motivation or novelty introduced by their study. An in-depth analysis of the results is missing, and the authors should further develop critical appraisal in their discussion. The quality of some figure is poor. In general, the study was poorly developed, and, at this point, it does not meet the journal's standards.

Author Response

Point :The manuscript presents several flaws. Firstly, it is not clear if there is any substantial contribution from this work. The literature review was not properly addressed. It seems paper does not have a clear objective and different kind of analysis have been done which cause to make difficulty to have a specific direction. In addition to the problem in the objective and methodology section, the interpretation of the results is not clear. The Mann-Kendall test does not use properly, and it recommend that authors review the theory of Mann-Kendall test and have an appropriate use of the trend analysis test. In addition, the authors have failed to clearly explain the importance of this work, as well as to point out which is the substantial contribution of this paper. I suggest adding more analysis to show the uniqueness of your study. In general, it is not clear either the relevance, motivation or novelty introduced by their study. An in-depth analysis of the results is missing, and the authors should further develop critical appraisal in their discussion. The quality of some figure is poor. In general, the study was poorly developed, and, at this point, it does not meet the journal's standards.

Response : Amendments are added to the manuscript with regards to the comments

Author Response File: Author Response.pdf

Reviewer 4 Report

Mayor comments

I think that the methodology section is too short. The authors briefly mention methods they are going to use for data analysis. It gives the impression that the authors are too concentrated on the methodology, unfortunately, without regard to the correct interpretation of the results. Both, the xwt and cwt transformations are not commonly used in environmental/natural sciences or climatology in particular, and the paper is mainly addressed to the specialists in these fields. Therefore, I suggest a more detailed discussion on these transformations (including parameters) and how to interpret the results.

The selection of climate indices is also dubious to me. It seems that the authors have not fully thought about which indexes should be analyzed. I do not deny teleconnection, but I would like to underline the overly laconic treatment of the topic and the lack of justification for the selection of indicators or their hierarchy. I understand that it is difficult to find publications on the impact of climate patterns on the African continent, but one can still use Western Europe.

The discussion and conclusion chapters are also far too short. There is no discussion with the results of other studies (only 4 studies were mentioned) and the results were raw/poor and lacked interpretation.

Minor comments

I realize that the standard in the journal is to provide citations as a number in brackets, but treating this entry/notation as a noun in a sentence makes reading difficult, e.g. "In the work [4] report…” (p. 1, line 42). I suggest changing this and other similar phrases into an impersonal form or using a surname, e.g. " In [4], there is reported…." or "Heino el al., in the paper [4], report that… ."

In Page 6, lines 171-172 - there is a reference to the figure 4, but the description in the text does not match the figure title. Same for figure 5.

Finally, the paper consists minor editing errors and some linguistic clumsiness, which can be eliminated in the next, revised version of the paper.

Author Response

Point 1 I realize that the standard in the journal is to provide citations as a number in brackets, but treating this entry/notation as a noun in a sentence makes reading difficult, e.g. "In the work [4] report…” (p. 1, line 42). I suggest changing this and other similar phrases into an impersonal form or using a surname, e.g. " In [4], there is reported…." or "Heino el al., in the paper [4], report that… ."

Response 1: Amendments added

Point 2: In Page 6, lines 171-172 - there is a reference to the figure 4, but the description in the text does not match the figure title. Same for figure 5.

Response 2: In methods section we announce abbreviations used in the text while the figure are named after the corresponding analysis.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I see the authors of the manuscript ‘Global climate patterns impacts on long-term Olive yields in Northwestern Africa: Case from Souss-Massa region‘ have made efforts to improve the manuscript. All recomendations are reflected in the text.

Ln 80, 81 – The underlined in yellow text is not clear formulated.

Ln 156 – Figure 2 needs to be in higher resolution, the axess to be readable.

Ln 190 - There is no full sentence; what does it mean ‘For (lag= -1).‘?

Ln 233, 234 – The new sentence in red needs from English improvement, now is not clear.

Author Response

Response to Reviewer 1 Comments-

Round 2

Reply: We would like to thank the reviewer for the careful reading of the manuscript and for the constructive remarks, which helped improve the manuscript.

Point 1: Ln 80, 81 – The underlined in yellow text is not clear formulated.

Response 2 All the text underlined in yellow is reformulated

Point 2: Ln 156 – Figure 2 needs to be in higher resolution, the axess to be readable.

Response 2 The axes are modified and figure with higher resolution.

Point 3: Ln 190 - There is no full sentence; what does it mean ‘For (lag= -1).‘?

Response 3 For (lag= -1) is typing error and is removed.

Point 4: Ln 233, 234 – The new sentence in red needs from English improvement, now is not clear.

Response 4 The sentence is reformulated.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors have made substantial and valuable changes to the manuscript and I appreciate their efforts to improve the manuscript. I have no further comments.

Author Response

Response to Reviewer 3 Comments-

2 Round

Reply: We would like to thank the reviewer for the careful reading of the manuscript and for the constructive remarks.

Reviewer 4 Report

Please consider my major comments from the first round of reviews. As for the minor remarks, I still think that the figure titles (4 and 5) are not the same as the ones described in the text. The paper still consists minor editing errors and some linguistic clumsiness, which can be eliminated in the next, revised version of the paper.

Author Response

Response to Reviewer 4 Comments-

2 Round

Reply: We would like to thank the reviewer for the careful reading of the manuscript and for the constructive remarks.

Point 1: Please consider my major comments from the first round of reviews. As for the minor remarks, I still think that the figure titles (4 and 5) are not the same as the ones described in the text. The paper still consists minor editing errors and some linguistic clumsiness, which can be eliminated in the next, revised version of the paper.

Response 1: The figures 4 and 5 are now corresponding to the text. Editing errors where corrected.

Author Response File: Author Response.pdf

Round 3

Reviewer 4 Report

I recommend this paper for publication.