المؤلفون: George Zodiatis, Steve Brenner, Isaac Gertman, Tal Ozer, Simona Simoncelli, Marinos Ioannou, Sotiris Savva

المصدر: Frontiers in Marine Science, Vol 9 (2023)

مصطلحات موضوعية: Levantine basin, mesoscale circulation, anticyclonic eddies, mid Mediterranean jet, modified Atlantic water, Eastern Mediterranean Transient Water, Science, General. Including nature conservation, geographical distribution, QH1-199.5

الوصف: The in-situ data gathered over two decades since mid-1990s in the South-Eastern Levantine Basin from 34 hydrographic campaigns and from 35 bi-weekly and monthly Voluntary Observing Ships (VOS) transects, after the pioneering POEM cruises, have provided insight on the dominant meso-scale coherent circulation features of this sub-basin. The most pronounced feature, the anticyclonic Cyprus Eddy, migrates over the broad region of the Eratosthenes seamount and exhibits significant seasonal and inter-annual spatial-temporal variability. Another prominent structure of the sub-basin is the anticyclonic Shikmona Eddy generated by instabilities of the strong northward flowing jet along the south-easternmost shelf and slope of the Levantine basin. Its evolution and co-existence with the Cyprus Eddy, cause the periodic re-establishment of the Shikmona Gyre, which was first observed during the POEM cruises in mid-1980s. The offshore, cross basin, eastward flowing Mid-Mediterranean Jet (MMJ) defines the northern and southern flanks of these sub-basin scale anticyclonic eddies and transports the lower salinity Modified Atlantic Water (MAW) in the subsurface layer, through the warmest and most saline waters of the Mediterranean. Periodically, the MMJ bifurcates and/or is diverted northward, along the western coast of Cyprus due to westward and northward spatial fluctuations of the Cyprus Eddy’s western boundaries. The current long term in-situ monitoring of the sub-basin provides an overview of the extent of the main water masses and characterizes their variability throughout the period considered. The analysis of the data indicates an increase of the temperature and salinity of the Levantine Surface Water (LSW) and of the subsurface MAW. The Eastern Mediterranean Transient Water (EMTW) is shown to occupy the deep cavities in the vicinity of the Eratosthenes seamount while its upper boundary was found to be lifted to shallower depths over a period of two decades.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmars.2022.1074504/fullTest; https://doaj.org/toc/2296-7745Test

الوصول الحر: https://doaj.org/article/5dc22fc997654e6ca3194ef4eaa89a99Test

المؤلفون: Tal Ozer, Isaac Gertman, Hezi Gildor, Barak Herut

المصدر: Frontiers in Marine Science, Vol 8 (2022)

مصطلحات موضوعية: seawater, salinity, climate change, inter-annual, Mediterranean Sea, temperature, Science, General. Including nature conservation, geographical distribution, QH1-199.5

الوصف: The high variability of coastal waters together with the growing need for assessing the state of the marine coastal ecosystem, require continuous monitoring at exceptional resolution and quality, especially during the Anthropocene changing seas. We perform a comprehensive analysis of a decadal (March 2011 to June 2021) thermohaline variability of the East Levantine Basin (LB) coastal waters (continuous measurements), its predominating temporal trends and their linkage with atmospheric forcing and advection. We identify statistically significant long-term warming and salinification trends with yearly rates of 0.048°C and 0.006, respectively. Through the use of the X11-ARIMA method temperature and salinity inter-annual trends are examined and associated with previously published open ocean dynamics as well as model reanalysis. We study the linkage between Northern and Southern coastal locations, and identify the along shore northward current as a primary cause of positive temperature anomalies arriving from the south. The coastal salinity long-term trend demonstrates a connection to local precipitation. A less coherent seasonal sequence is found with a bimodal behavior, where, salinity values drop in August on several summers. This drop is attributed to the intensification of the along shore current in the period of June-July, potentially advecting more Atlantic Water. The observations presented here emphasize the relatively strong coupling between coastal water and the open ocean, the influence of the general surface circulation of the LB on the coastal zone and the faster response time and higher sensitivity of the coastal environment to atmospheric forcing.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmars.2021.799457/fullTest; https://doaj.org/toc/2296-7745Test

الوصول الحر: https://doaj.org/article/827024f2041b41359f187ddab5e468f9Test

المؤلفون: Guy Sisma-Ventura, Nurit Kress, Jacob Silverman, Yaron Gertner, Tal Ozer, Eli Biton, Ayah Lazar, Isaac Gertman, Eyal Rahav, Barak Herut

المصدر: Frontiers in Marine Science, Vol 7 (2021)

مصطلحات موضوعية: East Mediterranean, deep water, EMT, time series, oxygen decline, nutrients, Science, General. Including nature conservation, geographical distribution, QH1-199.5

الوصف: Long-term trends in oxygen, salinity, and nutrients were followed in the Southeastern Mediterranean (SEMS) deep waters from 2002 to 2020. Results show a net decrease in oxygen since 2008 of −0.5 ± 0.1 μmol kg−1 yr−1 in the bathypelagic depths (1,200–2,000 m). Multiannual variability in oxygen levels superimposed this trend, and is likely associated with variations in thermohaline fluxes. The 2020 mean oxygen concentration of 179.5 ± 2.3 μmol kg−1 is comparable to the pre-Eastern Mediterranean Transient (EMT) mean value. The post-EMT signature is clearly demonstrated in both oxygen and salinity over the period of 2002–2013, but since 2014 it diminished, mainly due to mixing of the Aegean deep water (AegDW) mass with the overlying old Adriatic water mass. This trend reflects a switch back to the pre-EMT regime, characterized by thermohaline homogeneity of the deep water column in the SEMS. The long-term decline of deep water oxygen levels is also accompanied by a corresponding increase in dissolved inorganic nutrients, supporting aging of the deep water masses. Our results suggest that ventilation of the SEMS deep water is currently occurring at a lower, pre-EMT rate, probably as a result of moderated deep water formation in recent time.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmars.2020.598686/fullTest; https://doaj.org/toc/2296-7745Test

الوصول الحر: https://doaj.org/article/6d0106b927174538b85cf0afa4c04eecTest

المؤلفون: Joaquín Tintoré, Nadia Pinardi, Enrique Álvarez-Fanjul, Eva Aguiar, Diego Álvarez-Berastegui, Marco Bajo, Rosa Balbin, Roberto Bozzano, Bruno Buongiorno Nardelli, Vanessa Cardin, Benjamin Casas, Miguel Charcos-Llorens, Jacopo Chiggiato, Emanuela Clementi, Giovanni Coppini, Laurent Coppola, Gianpiero Cossarini, Alan Deidun, Salud Deudero, Fabrizio D'Ortenzio, Aldo Drago, Massimiliano Drudi, Ghada El Serafy, Romain Escudier, Patrick Farcy, Ivan Federico, Juan Gabriel Fernández, Christian Ferrarin, Cristina Fossi, Constantin Frangoulis, Francois Galgani, Slim Gana, Jesús García Lafuente, Marcos García Sotillo, Pierre Garreau, Isaac Gertman, Lluis Gómez-Pujol, Alessandro Grandi, Daniel Hayes, Jaime Hernández-Lasheras, Barak Herut, Emma Heslop, Karim Hilmi, Melanie Juza, George Kallos, Gerasimos Korres, Rita Lecci, Paolo Lazzari, Pablo Lorente, Svitlana Liubartseva, Ferial Louanchi, Vlado Malacic, Gianandrea Mannarini, David March, Salvatore Marullo, Elena Mauri, Lorinc Meszaros, Baptiste Mourre, Laurent Mortier, Cristian Muñoz-Mas, Antonio Novellino, Dominique Obaton, Alejandro Orfila, Ananda Pascual, Sara Pensieri, Begoña Pérez Gómez, Susana Pérez Rubio, Leonidas Perivoliotis, George Petihakis, Loic Petit de la Villéon, Jenny Pistoia, Pierre-Marie Poulain, Sylvie Pouliquen, Laura Prieto, Patrick Raimbault, Patricia Reglero, Emma Reyes, Paz Rotllan, Simón Ruiz, Javier Ruiz, Inmaculada Ruiz, Luis Francisco Ruiz-Orejón, Baris Salihoglu, Stefano Salon, Simone Sammartino, Agustín Sánchez Arcilla, Antonio Sánchez-Román, Gianmaria Sannino, Rosalia Santoleri, Rafael Sardá, Katrin Schroeder, Simona Simoncelli, Sarantis Sofianos, Georgios Sylaios, Toste Tanhua, Anna Teruzzi, Pierre Testor, Devrim Tezcan, Marc Torner, Francesco Trotta, Georg Umgiesser, Karina von Schuckmann, Giorgia Verri, Ivica Vilibic, Mustafa Yucel, Marco Zavatarelli, George Zodiatis

المصدر: Frontiers in Marine Science, Vol 6 (2019)

مصطلحات موضوعية: observing and forecasting systems, sustained observations, ocean variability, FAIR data, climate, operational services, Science, General. Including nature conservation, geographical distribution, QH1-199.5

الوصف: The Mediterranean community represented in this paper is the result of more than 30 years of EU and nationally funded coordination, which has led to key contributions in science concepts and operational initiatives. Together with the establishment of operational services, the community has coordinated with universities, research centers, research infrastructures and private companies to implement advanced multi-platform and integrated observing and forecasting systems that facilitate the advancement of operational services, scientific achievements and mission-oriented innovation. Thus, the community can respond to societal challenges and stakeholders needs, developing a variety of fit-for-purpose services such as the Copernicus Marine Service. The combination of state-of-the-art observations and forecasting provides new opportunities for downstream services in response to the needs of the heavily populated Mediterranean coastal areas and to climate change. The challenge over the next decade is to sustain ocean observations within the research community, to monitor the variability at small scales, e.g., the mesoscale/submesoscale, to resolve the sub-basin/seasonal and inter-annual variability in the circulation, and thus establish the decadal variability, understand and correct the model-associated biases and to enhance model-data integration and ensemble forecasting for uncertainty estimation. Better knowledge and understanding of the level of Mediterranean variability will enable a subsequent evaluation of the impacts and mitigation of the effect of human activities and climate change on the biodiversity and the ecosystem, which will support environmental assessments and decisions. Further challenges include extending the science-based added-value products into societal relevant downstream services and engaging with communities to build initiatives that will contribute to the 2030 Agenda and more specifically to SDG14 and the UN's Decade of Ocean Science for sustainable development, by this contributing to bridge the science-policy gap. The Mediterranean observing and forecasting capacity was built on the basis of community best practices in monitoring and modeling, and can serve as a basis for the development of an integrated global ocean observing system.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/article/10.3389/fmars.2019.00568/fullTest; https://doaj.org/toc/2296-7745Test

الوصول الحر: https://doaj.org/article/07e13f2b75d1402e851f133c05ec3d5eTest

المؤلفون: Elad Dakar, José Manuel Fernández Jaramillo, Isaac Gertman, Roberto Mayerle, Ron Goldman

المصدر: Coastal Engineering Journal. 65:309-324

مصطلحات موضوعية: Modeling and Simulation, Ocean Engineering, Civil and Structural Engineering

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::0dede450b207515f2ff77dfbd2c91b85Test
https://doi.org/10.1080/21664250.2023.2190002Test

المؤلفون: Steve Brenner, Isaac Gertman, Tal Ozer, Simona Simoncelli, George Zodiatis

الوصف: An analysis of in-situ data gathered over the two decade post POEM period in the South-Eastern Levantine Basin from extensive hydrographic (CTD) campaigns and VOS XBT transects, along with data provided by the latest SeaDataCloud Mediterranean Sea Temperature and Salinity climatology (http://dx.doi.org/10.12770/3f8eaace-9f9b-4b1b-a7a4-9c55270e205aTest) and the Mediterranean Sea Physics Reanalysis from the Copernicus Marine Service (CMS; https://data.marine.copernicus.eu/product/MEDSEA_MULTIYEAR_PHY_006_004Test), have all provided insight on the dominant, coherent, meso-scale, circulation features as well as the evolution and variability of the thermohaline properties of the main water masses in this sub-basin. The most pronounced feature, the warm core Cyprus Eddy, migrates over the broad region of the Eratosthenes seamount and exhibits significant seasonal and inter-annual spatio-temporal variability. Another prominent structure is the anticyclonic Shikmona Eddy generated periodically due to instabilities of the strong northward flowing jet along the south-easternmost shelf and slope of the Levantine basin. Its evolution and co-existence with the Cyprus Eddy for periods of a few months, affects the temporal re-establishment of the Shikmona Gyre, which was first observed during the POEM cruises in the mid 1980s. The eastward flowing Mid Mediterranean Jet (MMJ) defines the northern flanks of these sub-basin scale eddies and transports the lower salinity Modified Atlantic Water (MAW) through the warmest and most saline region of the Mediterranean. Periodically the MMJ bifurcates and/or is diverted northward, along the western coast of Cyprus due to spatial fluctuations of the Cyprus Eddy. Four active periods were identified with either a dominant Cyprus Eddy only or coexisting Cyprus and Shikmona Eddies. This long term in-situ monitoring also provides an overview of the extent of the main water masses and characterizes their variability throughout the period considered. The temperature and salinity of the Levantine Surface Water (LSW) and of the subsurface MAW have increased. The Eastern Mediterranean Transient Water (EMTW) is shown to occupy the deep cavities, below the Eastern Mediterranean Deep Water (EMDW), in the vicinity of the Eratosthenes seamount while its upper boundary was lifted to shallower depths over the same period.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::070fd02f13c63386b80420dcb3251e2cTest
https://doi.org/10.5194/egusphere-egu23-14768Test

المؤلفون: Natalia Belkin, Tamar Guy-Haim, Maxim Rubin-Blum, Ayah Lazar, Guy Sisma-Ventura, Rainer Kiko, Arseniy R. Morov, Tal Ozer, Isaac Gertman, Barak Herut, Eyal Rahav

المصدر: Ocean Science (1812-0784) (Copernicus Gesellschaft Mbh), 2022-05, Vol. 18, N. 3, P. 693-715

مصطلحات موضوعية: General Medicine

الوصف: Planktonic food webs were studied contemporaneously in a mesoscale cyclonic (upwelling, ∼ 13 months old) and an anticyclonic (downwelling, ∼ 2 months old) eddy as well as in an uninfluenced background situation in the oligotrophic southeastern Mediterranean Sea (SEMS) during late summer 2018. We show that integrated nutrient concentrations were higher in the cyclone compared to the anticyclone or the background stations by 2–13-fold. Concurrently, Synechococcus and Prochlorococcus were the dominant autotrophs abundance-wise in the oligotrophic anticyclone (∼ 300 × 1010 cells m−2). In the cyclone, functional groups such as dinoflagellates, Prymnesiophyceae and Ochrophyta contributed substantially to the total phytoplankton abundance (∼ 14 × 1010 cells m−2), which was ∼ 65 % lower at the anticyclone and background stations (∼ 5 × 1010 cells m−2). Primary production was highest in the cyclonic eddy (191 mgCm-2d-1) and 2–5-fold lower outside the eddy area. Heterotrophic prokaryotic cell-specific activity was highest in the cyclone (∼ 10 fgCcell-1d-1), while the least productive cells were found in the anticyclone (4 fgCcell-1d-1). Total zooplankton biomass in the upper 300 m was 10-fold higher in the cyclone compared with the anticyclone or background stations (1337 vs. 112–133 mg C m−2, respectively). Copepod diversity was much higher in the cyclone (44 species), compared to the anticyclone (6 small-size species). Our results highlight that cyclonic and anticyclonic eddies show significantly different community structure and food-web dynamics in oligotrophic environments, with cyclones representing productive oases in the marine desert of the SEMS.

وصف الملف: text; application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b31628fe9d21c7d2656ab4385297ac3fTest
https://doi.org/10.5194/os-18-693-2022Test

المؤلفون: Natalia Belkin, Tamar Guy-Haim, Maxim Rubin-Blum, Ayah Lazar, Guy Sisma-Ventura, Rainer Kiko, Arseniy R. Morov, Tal Ozer, Isaac Gertman, Barak Herut, Eyal Rahav

الوصف: Planktonic food-webs were studied contemporaneously in a mesoscale cyclonic (upwelling, ~13 months old) and an anti-cyclonic (down-welling, ~2 months old) eddies, as well as in an uninfluenced-background situation in the oligotrophic southeastern Mediterranean Sea (SEMS) during late summer 2018. We show that integrated nutrients concentrations were higher at the cyclone compared to the anti-cyclone or the background stations by 2–13 fold. Concurrently, Synechococcus and Prochlorococcus were the dominant community component abundance-wise in the oligotrophic anti-cyclone (~300 × 1010 cells m−2). In the cyclone, pico- and nanoeukaryotes such as dinoflagellates, Prymnesiophyceae and Ochrophyta contributed substantially to the total phytoplankton abundnce (~14 × 1010 cells m−2) which was ~65 % lower in the anti-cyclone/background stations (~5 × 1010 cells m−2). Primary production was highest in the cyclonic eddy (191 mg C m−2 d−1) and was 2–5 fold lower outside the eddy area. The calculated doubling time of phytoplankton was ~3 days in the cyclone and ~5–10 days at the anti-cyclone/background stations, further reflecting the nutritional differences between these environments. Heterotrophic prokaryotic cell-specific activity was highest in the cyclone (~10 fg C cell−1 d−1), while the least productive cells were found in the anti-cyclone (4 fg C cell−1 d−1). The calculated doubling time of heterotrophic bacteria were 1.4 days in the cyclone and 2.5–3.5 days at the anti-cyclone/background stations. Total zooplankton biomass in the upper 300 m was tenfold higher in the cyclone compared with the anti-cyclone or background stations (1337 vs. 112–133 mg C m−2, respectively). Copepod diversity was much higher in the cyclone (44 species), compared to the anti-cyclone (6 small-size species). Our results highlight that cyclonic and anti-cyclonic eddies show significantly different community compositions and food-web dynamics in oligotrophic environments, with cyclones representing productive oases in the marine desert of the SEMS.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::22ac3e7cd2a74041d8798ad6bd2d2982Test
https://doi.org/10.5194/os-2021-124Test

المؤلفون: Natalia Belkin, Tamar Guy-Haim, Maxim Rubin-Blum, Ayah Lazar, Guy Sisma-Ventura, Rainer Kiko, Arseniy R. Morov, Tal Ozer, Isaac Gertman, Barak Herut, Eyal Rahav

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::8dfa3cf624b6685b75c65b50dc5b40ebTest
https://doi.org/10.5194/os-2021-124-supplementTest

المؤلفون: Tal Ozer (10010780), Isaac Gertman (10010789), Hezi Gildor (4572535), Barak Herut (822531)

مصطلحات موضوعية: Oceanography, Marine Biology, Marine Geoscience, Biological Oceanography, Chemical Oceanography, Physical Oceanography, Marine Engineering, seawater, salinity, climate change, inter-annual, Mediterranean Sea, temperature, variability, mesoscale

الوصف: The high variability of coastal waters together with the growing need for assessing the state of the marine coastal ecosystem, require continuous monitoring at exceptional resolution and quality, especially during the Anthropocene changing seas. We perform a comprehensive analysis of a decadal (March 2011 to June 2021) thermohaline variability of the East Levantine Basin (LB) coastal waters (continuous measurements), its predominating temporal trends and their linkage with atmospheric forcing and advection. We identify statistically significant long-term warming and salinification trends with yearly rates of 0.048°C and 0.006, respectively. Through the use of the X11-ARIMA method temperature and salinity inter-annual trends are examined and associated with previously published open ocean dynamics as well as model reanalysis. We study the linkage between Northern and Southern coastal locations, and identify the along shore northward current as a primary cause of positive temperature anomalies arriving from the south. The coastal salinity long-term trend demonstrates a connection to local precipitation. A less coherent seasonal sequence is found with a bimodal behavior, where, salinity values drop in August on several summers. This drop is attributed to the intensification of the along shore current in the period of June-July, potentially advecting more Atlantic Water. The observations presented here emphasize the relatively strong coupling between coastal water and the open ocean, the influence of the general surface circulation of the LB on the coastal zone and the faster response time and higher sensitivity of the coastal environment to atmospheric forcing.

العلاقة: https://figshare.com/articles/dataset/Data_Sheet_1_Thermohaline_Temporal_Variability_of_the_SE_Mediterranean_Coastal_Waters_Israel_Long-Term_Trends_Seasonality_and_Connectivity_docx/18738509Test

الإتاحة: https://doi.org/10.3389/fmars.2021.799457.s001Test