Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea
We observed interannual changes in the temperature and salinity of the surface layer of the Adriatic Sea when measured during the period 2005–2020. We observed non-stationarity and a positive linear trend in the series of mixed layer depth, heat storage, and potential energy anomalies. This non-stat...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/10/7/848 |
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| author | Frano Matić Tomislav Džoić Hrvoje Kalinić Leon Ćatipović David Udovičić Tea Juretić Lucija Rakuljić Daria Sršen Vjekoslav Tičina |
| author_facet | Frano Matić Tomislav Džoić Hrvoje Kalinić Leon Ćatipović David Udovičić Tea Juretić Lucija Rakuljić Daria Sršen Vjekoslav Tičina |
| author_sort | Frano Matić |
| collection | DOAJ |
| description | We observed interannual changes in the temperature and salinity of the surface layer of the Adriatic Sea when measured during the period 2005–2020. We observed non-stationarity and a positive linear trend in the series of mixed layer depth, heat storage, and potential energy anomalies. This non-stationarity was related to the climate regime that prevailed between 2011 and 2017. We observed significant changes in the interannual variability of salinity above and below the mixed layer depth and a positive difference in the surface barrier layer. In an effort to reconstruct the cause of this phenomenon, a multi-stage investigation was conducted. The first suspected culprit was the change in wind regime over the Mediterranean and Northeast Atlantic regions in September. Using the growing neural gas algorithm, September wind fields over the past 40 years were classified into nine distinct patterns. Further analysis of the CTD data indicated an increase in heat storage, a physical property of the Adriatic Sea known to be strongly influenced by the inflow of warm water masses controlled by the bimodal oscillating system (BiOS). The observed increase in salinity confirmed the assumption that BiOS activity affects heat storage. Unexpectedly, this analysis showed that an inverse vertical salinity profile was present during the summer months of 2015, 2017, and 2020, which can only be explained by salinity changes being a dominant factor. In addition, the aforementioned wind regime caused an increase in energy loss through latent energy dissipation, contributing to an even larger increase in salinity. While changes in the depth of the mixed layer in the Adriatic are usually due to temperature changes, this phenomenon was primarily caused by abrupt changes in salinity due to a combination of BiOS and local factors. This is the first record of such an event. |
| first_indexed | 2024-03-09T03:17:53Z |
| format | Article |
| id | doaj.art-5945c296a21444cda12ae6d6f600bfd8 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-09T03:17:53Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-5945c296a21444cda12ae6d6f600bfd82023-12-03T15:14:31ZengMDPI AGJournal of Marine Science and Engineering2077-13122022-06-0110784810.3390/jmse10070848Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic SeaFrano Matić0Tomislav Džoić1Hrvoje Kalinić2Leon Ćatipović3David Udovičić4Tea Juretić5Lucija Rakuljić6Daria Sršen7Vjekoslav Tičina8Institute of Oceanography and Fisheries, 21000 Split, CroatiaInstitute of Oceanography and Fisheries, 21000 Split, CroatiaFaculty of Science, University of Split, 21000 Split, CroatiaFaculty of Science, University of Split, 21000 Split, CroatiaInstitute of Oceanography and Fisheries, 21000 Split, CroatiaInstitute of Oceanography and Fisheries, 21000 Split, CroatiaUniversity Department of Marine Studies, University of Split, 21000 Split, CroatiaUniversity Department of Marine Studies, University of Split, 21000 Split, CroatiaInstitute of Oceanography and Fisheries, 21000 Split, CroatiaWe observed interannual changes in the temperature and salinity of the surface layer of the Adriatic Sea when measured during the period 2005–2020. We observed non-stationarity and a positive linear trend in the series of mixed layer depth, heat storage, and potential energy anomalies. This non-stationarity was related to the climate regime that prevailed between 2011 and 2017. We observed significant changes in the interannual variability of salinity above and below the mixed layer depth and a positive difference in the surface barrier layer. In an effort to reconstruct the cause of this phenomenon, a multi-stage investigation was conducted. The first suspected culprit was the change in wind regime over the Mediterranean and Northeast Atlantic regions in September. Using the growing neural gas algorithm, September wind fields over the past 40 years were classified into nine distinct patterns. Further analysis of the CTD data indicated an increase in heat storage, a physical property of the Adriatic Sea known to be strongly influenced by the inflow of warm water masses controlled by the bimodal oscillating system (BiOS). The observed increase in salinity confirmed the assumption that BiOS activity affects heat storage. Unexpectedly, this analysis showed that an inverse vertical salinity profile was present during the summer months of 2015, 2017, and 2020, which can only be explained by salinity changes being a dominant factor. In addition, the aforementioned wind regime caused an increase in energy loss through latent energy dissipation, contributing to an even larger increase in salinity. While changes in the depth of the mixed layer in the Adriatic are usually due to temperature changes, this phenomenon was primarily caused by abrupt changes in salinity due to a combination of BiOS and local factors. This is the first record of such an event.https://www.mdpi.com/2077-1312/10/7/848mixed layer depthclimate regimesheat storagesea surface layerheat fluxesneural gas |
| spellingShingle | Frano Matić Tomislav Džoić Hrvoje Kalinić Leon Ćatipović David Udovičić Tea Juretić Lucija Rakuljić Daria Sršen Vjekoslav Tičina Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea Journal of Marine Science and Engineering mixed layer depth climate regimes heat storage sea surface layer heat fluxes neural gas |
| title | Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea |
| title_full | Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea |
| title_fullStr | Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea |
| title_full_unstemmed | Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea |
| title_short | Observation of Abrupt Changes in the Sea Surface Layer of the Adriatic Sea |
| title_sort | observation of abrupt changes in the sea surface layer of the adriatic sea |
| topic | mixed layer depth climate regimes heat storage sea surface layer heat fluxes neural gas |
| url | https://www.mdpi.com/2077-1312/10/7/848 |
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