Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea
The warming of the surface ocean is expected to increase the stratification of the upper water column. This would decrease the efficiency of the wind-induced mixing, reducing the nutrient supply to the euphotic layer and the productivity of the oceans. Climatic projections show that the Mediterranea...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-06-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2022.901893/full |
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| author | Manuel Vargas-Yáñez Francina Moya Rosa Balbín Rocío Santiago Enrique Ballesteros Ricardo F. Sánchez-Leal Patricia Romero Ma Carmen García-Martínez |
| author_facet | Manuel Vargas-Yáñez Francina Moya Rosa Balbín Rocío Santiago Enrique Ballesteros Ricardo F. Sánchez-Leal Patricia Romero Ma Carmen García-Martínez |
| author_sort | Manuel Vargas-Yáñez |
| collection | DOAJ |
| description | The warming of the surface ocean is expected to increase the stratification of the upper water column. This would decrease the efficiency of the wind-induced mixing, reducing the nutrient supply to the euphotic layer and the productivity of the oceans. Climatic projections show that the Mediterranean Sea will experience a strong warming and salting along the twenty first century. Nevertheless, very few works have found and quantified changes in the water column stratification of the Western Mediterranean. In this work, we obtain time series of Mixed Layer Depth (MLD) along the Spanish Mediterranean waters and the Gulf of Cádiz, using periodic CTD profiles collected under the umbrella of the Ocean Observing system of the Instituto Español de Oceanografía (IEO-CSIC). The length of the time series analyzed is variable, depending on the geographical area, but in some cases these time series extend from the beginning of the 1990s decade. Our results show that at present, no statistically significant changes can be detected. These results are confirmed by the analysis of MLD time series obtained from Argo profilers. Some of the meteorological factors that could affect the water column stratification (wind intensity and precipitation rates) did not experience significant changes for the 1990-2021 period, neither were observed long-term changes in the chlorophyll concentration. The hypothesis proposed to explain this lack of trends, is that the salinity increase of the surface waters has compensated for the warming, and consequently, the density of the upper layer of the Western Mediterranean (WMED) has remained constant. As the wind intensity has not experienced significant trends, the stratification of the Spanish Mediterranean waters and those of the Gulf of Cádiz would have not been affected. Nevertheless, we do not discard that our results are a consequence of the short length of the available time series and the large variance of the variables analyzed, evidencing the importance of the maintenance of the ocean monitoring programs. |
| first_indexed | 2024-12-11T17:01:38Z |
| format | Article |
| id | doaj.art-22e875f6a8ce41fd994ac5ee404d64b5 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-11T17:01:38Z |
| publishDate | 2022-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-22e875f6a8ce41fd994ac5ee404d64b52022-12-22T00:57:48ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452022-06-01910.3389/fmars.2022.901893901893Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean SeaManuel Vargas-Yáñez0Francina Moya1Rosa Balbín2Rocío Santiago3Enrique Ballesteros4Ricardo F. Sánchez-Leal5Patricia Romero6Ma Carmen García-Martínez7Instituto Español de Oceanografía (IEO-CSIC). Centro Oceanográfico de Málaga., Málaga, SpainInstituto Español de Oceanografía (IEO-CSIC). Centro Oceanográfico de Málaga., Málaga, SpainInstituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Baleares., Palma, SpainInstituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Baleares., Palma, SpainInstituto Español de Oceanografía (IEO-CSIC). Centro Oceanográfico de Málaga., Málaga, SpainInstituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Cádiz., Cádiz, SpainInstituto Español de Oceanografía (IEO-CSIC). Centro Oceanográfico de Málaga., Málaga, SpainInstituto Español de Oceanografía (IEO-CSIC). Centro Oceanográfico de Málaga., Málaga, SpainThe warming of the surface ocean is expected to increase the stratification of the upper water column. This would decrease the efficiency of the wind-induced mixing, reducing the nutrient supply to the euphotic layer and the productivity of the oceans. Climatic projections show that the Mediterranean Sea will experience a strong warming and salting along the twenty first century. Nevertheless, very few works have found and quantified changes in the water column stratification of the Western Mediterranean. In this work, we obtain time series of Mixed Layer Depth (MLD) along the Spanish Mediterranean waters and the Gulf of Cádiz, using periodic CTD profiles collected under the umbrella of the Ocean Observing system of the Instituto Español de Oceanografía (IEO-CSIC). The length of the time series analyzed is variable, depending on the geographical area, but in some cases these time series extend from the beginning of the 1990s decade. Our results show that at present, no statistically significant changes can be detected. These results are confirmed by the analysis of MLD time series obtained from Argo profilers. Some of the meteorological factors that could affect the water column stratification (wind intensity and precipitation rates) did not experience significant changes for the 1990-2021 period, neither were observed long-term changes in the chlorophyll concentration. The hypothesis proposed to explain this lack of trends, is that the salinity increase of the surface waters has compensated for the warming, and consequently, the density of the upper layer of the Western Mediterranean (WMED) has remained constant. As the wind intensity has not experienced significant trends, the stratification of the Spanish Mediterranean waters and those of the Gulf of Cádiz would have not been affected. Nevertheless, we do not discard that our results are a consequence of the short length of the available time series and the large variance of the variables analyzed, evidencing the importance of the maintenance of the ocean monitoring programs.https://www.frontiersin.org/articles/10.3389/fmars.2022.901893/fullmixed layer depthWestern Mediterraneanclimate changeocean productivityocean observing system |
| spellingShingle | Manuel Vargas-Yáñez Francina Moya Rosa Balbín Rocío Santiago Enrique Ballesteros Ricardo F. Sánchez-Leal Patricia Romero Ma Carmen García-Martínez Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea Frontiers in Marine Science mixed layer depth Western Mediterranean climate change ocean productivity ocean observing system |
| title | Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea |
| title_full | Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea |
| title_fullStr | Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea |
| title_full_unstemmed | Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea |
| title_short | Seasonal and Long-Term Variability of the Mixed Layer Depth and its Influence on Ocean Productivity in the Spanish Gulf of Cádiz and Mediterranean Sea |
| title_sort | seasonal and long term variability of the mixed layer depth and its influence on ocean productivity in the spanish gulf of cadiz and mediterranean sea |
| topic | mixed layer depth Western Mediterranean climate change ocean productivity ocean observing system |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2022.901893/full |
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