scholarly journals Present climate trends and variability in thermohaline properties of the northern Adriatic shelf

Ocean Science ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 1351-1362 ◽  
Author(s):  
Ivica Vilibić ◽  
Petra Zemunik ◽  
Jadranka Šepić ◽  
Natalija Dunić ◽  
Oussama Marzouk ◽  
...  
Keyword(s):  
Time Series ◽  
Thermohaline Circulation ◽  
Adriatic Sea ◽  
Decadal Variability ◽  
Bottom Layer ◽  
Large Temperature ◽  
Climate Trends ◽  
Series Length ◽  
Northern Adriatic Sea ◽  
Northern Adriatic

Abstract. The paper documents seasonality, interannual-to-decadal variability, and trends in temperature, salinity, and density over a transect in the shallow northern Adriatic Sea (Mediterranean Sea) between 1979 and 2017. The amplitude of seasonality decreases with depth and is much larger in temperature and density than in salinity. Time series of temperature and salinity are correlated in the surface but not in the bottom layer. Trends in temperature are large (up to 0.6 ∘C over 10 years), significant through the area, and not sensitive to the sampling interval and time series length. In contrast, trends in salinity are largely small and insignificant and depend on the time series length. The warming of the area is more during spring and summer. Such large temperature trends and their spatial variability emphasize the importance of maintaining regular long-term observations for the proper estimation of thermohaline trends and their variability. This is particularly important in regions which are key for driving thermohaline circulation such as the northern Adriatic, with the potential to affect biogeochemical and ecological properties of the whole Adriatic Sea.

scholarly journals Present-climate trends and variability in thermohaline properties of the northern Adriatic shelf

2019 ◽  
Author(s):  
Ivica Vilibić ◽  
Petra Zemunik ◽  
Jadranka Šepic ◽  
Natalija Dunić ◽  
Oussama Marzouk ◽  
...  
Keyword(s):  
Time Series ◽  
Thermohaline Circulation ◽  
Adriatic Sea ◽  
Decadal Variability ◽  
Sampling Interval ◽  
Large Temperature ◽  
Climate Trends ◽  
Series Length ◽  
Northern Adriatic Sea ◽  
Northern Adriatic

Abstract. The paper documents seasonality, interannual to decadal variability and trends in temperature, salinity and density over a transect in the shallow northern Adriatic Sea (Mediterranean Sea) between 1979 and 2017. Amplitude of seasonality decreases with depth, and is much larger in temperature and density than in salinity. Interannual to decadal variability in temperature and salinity are differently correlated in surface and bottom layers, indicating different mechanisms which govern their variability. Trends in temperature are large (up to 6 °C over 100 years), significant through the area and not sensitive to the sampling interval and time series length. In contrast, trends in salinity are largely weak and insignificant and depend on the time series length. The warming of the area is stronger during spring and summer. Such large temperature trends and their spatial variability indicate substantial changes in the thermohaline circulation in this area known as a dense water formation site, with a potential to affect biogeochemical and ecological properties of the whole Adriatic Sea.

scholarly journals Modes of the BiOS-driven Adriatic Sea thermohaline variability

2021 ◽  
Author(s):  
Cléa Lumina Denamiel ◽  
Iva Tojčić ◽  
Petra Pranić ◽  
Ivica Vilibić
Keyword(s):  
Time Series ◽  
Thermohaline Circulation ◽  
Climate Model ◽  
Adriatic Sea ◽  
Decadal Variability ◽  
Current Speed ◽  
Empirical Orthogonal Functions ◽  
Climate Simulation ◽  
Orthogonal Functions ◽  
The Impact

Abstract In this study the impact of the Adriatic-Ionian Bimodal Oscillating System (BiOS) on the interannual to decadal variability of the Adriatic Sea thermohaline circulation is quantified during the 1987-2017 period with the numerical results of the Adriatic Sea and Coast (AdriSC) historical kilometer-scale climate simulation. The time series associated with the first five Empirical Orthogonal Functions (EOFs) computed from the salinity, temperature and current speed monthly detrended anomalies at 1-km resolution are correlated to the BiOS signal. First, it is found that the AdriSC climate model is capable to reproduce the BiOS-driven phases derived from in-situ observations along a long-term monitoring transect in the middle Adriatic. Then, for the entire Adriatic basin, high correlations to the 2-year delayed BiOS signal are obtained for the salinity and current speed first two EOF time series at 100 m depth and the sea-bottom Finally, the physical interpretation of the EOF spatial patterns reveals that Adriatic bottom temperatures are more influenced by the dense water circulation than the BiOS. These findings confirmed and generalized the known dynamics derived previously from observations, and the AdriSC climate model can thus be used to better understand the past and future BiOS-driven physical processes in the Adriatic Sea.

scholarly journals Ecological time series and integrative taxonomy unveil seasonality and diversity of the toxic diatom Pseudo-nitzschia H. Peragallo in the northern Adriatic Sea

Harmful Algae ◽  
2020 ◽  
Vol 93 ◽  
pp. 101773 ◽  
Author(s):  
Timotej Turk Dermastia ◽  
Federica Cerino ◽  
David Stanković ◽  
Janja Francé ◽  
Andreja Ramšak ◽  
...  
Keyword(s):  
Time Series ◽  
Adriatic Sea ◽  
Integrative Taxonomy ◽  
Northern Adriatic Sea ◽  
Northern Adriatic

scholarly journals A Generalization of the TRIX trophic index to the Adriatic Sea basin

2016 ◽  
Author(s):  
Emanuela Fiori ◽  
Marco Zavatarelli ◽  
Nadia Pinardi ◽  
Cristina Mazziotti ◽  
Carla Rita Ferrari
Keyword(s):  
Time Series ◽  
Adriatic Sea ◽  
Simulated Data ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
In Situ Data ◽  
Trophic Index ◽  
Scaling Parameters ◽  
Italian Legislation

Abstract. The Marine Strategy Framework Directive is pushing for new methodological approaches in order to protect the marine environment more effectively. The trophic index TRIX was developed by Vollenweider in 1998 for the coastal area of Emilia-Romagna (northern Adriatic Sea), and was exploited by Italian legislation to characterize the trophic state of coastal waters. In order to implement TRIX in different areas and for different time periods, we developed a methodology for the generalization of the index changing the scaling parameters. We compared the TRIX index calculated from in situ data ("in situ TRIX") with the corresponding index simulated with a coupled physics and biogeochemical numerical model ("model TRIX") implemented in the overall Adriatic Sea. The comparison between in situ and simulated data was carried out for a data time series in the Emilia-Romagna coastal strip. This study demonstrates the compatibility of the model with the in situ TRIX and the necessity to have time series longer than 10 years to evaluate properly the scaling parameters. The model TRIX is finally calculated for the whole Adriatic Sea showing trophic index differences across the Adriatic coastal areas.

scholarly journals The role of fisheries and the environment in driving the decline of elasmobranchs in the northern Adriatic Sea

2014 ◽  
Vol 71 (7) ◽  
pp. 1593-1603 ◽  
Author(s):  
Alberto Barausse ◽  
Vittoria Correale ◽  
Aleksia Curkovic ◽  
Licia Finotto ◽  
Emilio Riginella ◽  
...  
Keyword(s):  
Time Series ◽  
Adriatic Sea ◽  
Conservation Status ◽  
Catch Per Unit Effort ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Management Actions ◽  
Fish Market ◽  
Fishery Exploitation

Abstract Elasmobranch populations are declining worldwide, calling for urgent assessment of fishery exploitation and application of effective conservation strategies. Here, we applied a novel approach, integrating long-term time-series of landings (1945–2012) and extensive surveys at the fish market of Chioggia, Italy, home of the major fishing fleet of the northern Adriatic Sea, to evaluate the status of elasmobranch populations and fisheries in the one of the most fished Mediterranean basins. The time-series highlight a dramatic decline in elasmobranch landings, particularly for skates and catsharks (Scyliorhinus spp.), whose current catch rates are 2.4 and 10.6% of the average 1940s levels, respectively. These data likely reflect similar large reductions in abundance, as indicated by the analysis of catch-per unit-effort time-series. The biomass of landed skates and catsharks showed regular fluctuations that disappeared after the collapse of the landings. Elasmobranch market composition, assessed through the sampling of 11 900 specimens from 2006 to 2013, included 14 species, but was dominated by just two: Mustelus mustelus and M. punctulatus, which represented more than 60% of the catch. The proportion of sexually immature individuals was generally very high, up to 83% of landed females and 71% of landed males, depending on the species. Although some correlations were detected between landings and local hydrography or climatic indices, the analyses of landings and surveys at the fish market identified fishery exploitation as the main driver of the striking, long-term elasmobranch decline in the northern Adriatic Sea, calling for urgent management actions to improve the conservation status of these fish.

scholarly journals Observed and simulated trophic index (TRIX) values for the Adriatic Sea basin

2016 ◽  
Vol 16 (9) ◽  
pp. 2043-2054 ◽  
Author(s):  
Emanuela Fiori ◽  
Marco Zavatarelli ◽  
Nadia Pinardi ◽  
Cristina Mazziotti ◽  
Carla Rita Ferrari
Keyword(s):  
Time Series ◽  
Adriatic Sea ◽  
Simulated Data ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
In Situ Data ◽  
Trophic Index ◽  
Environmental Status ◽  
Italian Legislation

Abstract. The main scope of the Marine Strategy Framework Directive is to achieve good environmental status (GES) of the EU's marine waters by 2020, in order to protect the marine environment more effectively. The trophic index (TRIX) was developed by Vollenweider in 1998 for the coastal area of Emilia-Romagna (northern Adriatic Sea) and was used by the Italian legislation to characterize the trophic state of coastal waters. We compared the TRIX index calculated from in situ data (“in situ TRIX”) with the corresponding index simulated with a coupled physics and biogeochemical numerical model (“model TRIX”) implemented in the overall Adriatic Sea. The comparison between in situ and simulated data was carried out for a data time series on the Emilia-Romagna coastal strip. This study shows the compatibility of the model with the in situ TRIX and the importance of the length of the time series in order to get robust index estimates. The model TRIX is finally calculated for the whole Adriatic Sea, showing trophic index differences across the Adriatic coastal areas.

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