scholarly journals Tintinnid Ciliate Communities in Pre- and Post-Winter Conditions in the Southern Adriatic Sea (NE Mediterranean)

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2329 ◽  
Author(s):  
Jakica Njire ◽  
Mirna Batistić ◽  
Vedrana Kovačević ◽  
Rade Garić ◽  
Manuel Bensi
Keyword(s):  
Adriatic Sea ◽  
Sea Water ◽  
Dynamic Environment ◽  
Intermediate Water ◽  
The North ◽  
Winter Conditions ◽  
Winter Convection ◽  
Oceanic Species ◽  
Physical Forces ◽  
The Impact

The Southern Adriatic Sea is a dynamic region under the influence of diverse physical forces that modify sea water properties as well as plankton dynamics, abundance, and distribution in an intricate way. The most pronounced being: winter vertical convection, lateral exchanges between coastal and open sea waters, and the ingression of water masses of different properties into the Adriatic. We investigated the distribution and abundance of tintinnid species in this dynamic environment in pre- and post-winter conditions in 2015/2016. A strong ingression of the saline Levantine Intermediate Water, supported by the cyclonic mode of the North Ionian Gyre in 2015 and 2016, in December was associated with a high diversity of oceanic species. An unusual spatial distribution of neritic-estuarine species Codonellopsis schabi was observed in deeper layers along the analyzed transect, which emphasizes the strong influence of physical processes on deep water biology in the South Adriatic. A shift of population toward greater depths (mesopelagic) and modification of deep sea community structure was recorded in April as a consequence of the winter convection-driven sinking of tintinnids. Our findings indicate that tintinnid abundance and composition is heavily influenced by physical conditions and they are good indicators of the impact of physical forces, including climate changes, on marine environment.

scholarly journals “Sermo eorum sicut cancer serpit”. Chromatius of Aquileia against heresies

Vox Patrum ◽  
2018 ◽  
Vol 68 ◽  
pp. 443-455
Author(s):  
Miran Sajovic
Keyword(s):  
20Th Century ◽  
Adriatic Sea ◽  
Conference Paper ◽  
The North ◽  
Trade Center ◽  
The Impact ◽  
North End

Bishop Chromatius (in office from 388 to 407), whose episcopal see was a cosmopolitan trade-center at the north end of the Adriatic Sea with the name of Aquileia, was one of the most prominent bishops in the period. He is acquaint­ed with notable figures such as Ambrosius, Hieronymus, Rufinus, and Ioannes Chrysostomus and forth. Before being created a bishop, he was the secretary of bi­shop Valerianus and in the occasion of Council of Aquileia in 381, he had spoken against Arians. This Council was presided by Ambrosius and with its scale it could almost be considered as an ecumenical one. As shown in some of the Chromatius’ sermons, which are unearthed in the 20th century, he opposed not only to the ideas of Arians but also to the teaching of Fotinus, bishop of Sirmium. Chromatius was a very zealous fighter and he practically succeeded to uproot all heretical ideas in his diocese. The academia usually sees him as an anti-Arian theologian. After the Council of Constantinople (381), the Arian heresy seemed to be abated, but Chromatius said in one of his Tractatus, “Cuius (sc. Arii) discipuli hodieque oues Dei fallere ac decipere conantur per aliquantas ecclesias, sed iamdudum, magistro perfidiae prodito, discipuli latere non possunt”; it is evident that, the followers of Arius could still be found (with the mentioning of “hodie”, i.e. today) in the area of Aquileia, meanwhile one must not neglect the presence of the followers of Fotinus of Sirmium. The first part of my conference paper would be a general presentation of the religious situation in Aquileia at the time where Chromatius served as the local bishop; thus I will proceed with an in-depth reading on several passages of the Aquilerian bishop’s sermons (Sermones and Tractatus), in order to show the impact of the those heresies on his works and to identity his theological arguments against them. Among those teachings, there is the “unconquerable faith (invicta fide)”, which led to the surmounting (suppression) of heresies.

scholarly journals Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE section (GEOTRACES section GA01)

2018 ◽  
Author(s):  
Manon Tonnard ◽  
Hélène Planquette ◽  
Andrew R. Bowie ◽  
Pier van der Merwe ◽  
Morgane Gallinari ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Sea Water ◽  
North Atlantic Ocean ◽  
Deep Convection ◽  
Labrador Sea ◽  
Intermediate Water ◽  
The North ◽  
Irminger Sea ◽  
The North Atlantic

Abstract. Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient to sustain phytoplankton growth. Increasing DFe concentrations along the flow path of the Labrador Sea Water were attributed to sedimentary inputs from the Newfoundland Margin. Bottom waters from the Irminger Sea displayed high DFe concentrations likely due to the dissolution of Fe-rich particles from the Denmark Strait Overflow Water and the Polar Intermediate Water. Finally, the nepheloid layers were found to act as either a source or a sink of DFe depending on the nature of particles.

A Virtual Geostationary Ocean Colour Sensor to characterise the river-sea interaction over the North Adriatic Sea.

2020 ◽  
Author(s):  
Marco Bracaglia ◽  
Rosalia Santoleri ◽  
Gianluca Volpe ◽  
Simone Colella ◽  
Federica Braga ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Sea Water ◽  
Interdisciplinary Studies ◽  
Time Variability ◽  
Spatial And Temporal Variability ◽  
Ocean Colour ◽  
The North ◽  
Uncertainty Sources ◽  
Short Time ◽  
North Adriatic Sea

<p>Inherent optical properties (IOPs) and concentrations of the sea water components are key quantities in supporting the monitoring of the water quality and the study of the ecosystem functioning. In coastal waters, those quantities have a large spatial and temporal variability, due to river discharges and meteo-marine conditions, such as wind, wave and current, and their interaction with shallow water bathymetry. This short term variability can be adequately captured only using Geostationary Ocean Colour (OC) satellites, absent over the European seas.</p><p>In this study, to compensate the lack of an OC geostationary sensor over the North Adriatic Sea (NAS), the Virtual Geostationary Ocean Colour Sensor (VGOCS) dataset has been used. VGOCS contains data from several OC polar satellites, making available multiple images a day of the NAS, approaching the temporal resolution of a geostationary sensor.</p><p>Generally, data from different satellite sensors are characterized by different uncertainty sources and consequently, looking at two satellite images, it is not easy to ascertain how much of the observed differences are due to real processes. In the VGOCS dataset, the inter-sensor differences are reduced, as the satellite data were adjusted with a multi-linear regression algorithm based on in situ reflectance acquired in the gulf of Venice. Consequently, the use of the adjusted spectra as input in the retrieval of the IOPs and the concentrations allows performing a reliable analysis of the short-time bio-optical variability of the basin.</p><p>In this work, we demonstrate the suitability of VGOCS to better characterise the river-sea interaction and to understand the influence of the river forcing on the short time variability of IOPs and concentrations in the coastal areas. This variability will be analysed for different case studies characterised by a different regime of river discharges, using meteorological, hydrological, and oceanographic fields as ancillary variables. This new approach and the availability of this new set of data represent an opportunity for interdisciplinary studies, in support to and interacting also with modelling implementations in river-sea areas.</p>

scholarly journals Water masses in the Atlantic Ocean: characteristics and distributions

Ocean Science ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 463-486
Author(s):  
Mian Liu ◽  
Toste Tanhua
Keyword(s):  
Atlantic Ocean ◽  
Deep Water ◽  
Bottom Water ◽  
Water Mass ◽  
Sea Water ◽  
Weddell Sea ◽  
Water Masses ◽  
Global Ocean ◽  
Intermediate Water ◽  
The North

Abstract. A large number of water masses are presented in the Atlantic Ocean, and knowledge of their distributions and properties is important for understanding and monitoring of a range of oceanographic phenomena. The characteristics and distributions of water masses in biogeochemical space are useful for, in particular, chemical and biological oceanography to understand the origin and mixing history of water samples. Here, we define the characteristics of the major water masses in the Atlantic Ocean as source water types (SWTs) from their formation areas, and map out their distributions. The SWTs are described by six properties taken from the biased-adjusted Global Ocean Data Analysis Project version 2 (GLODAPv2) data product, including both conservative (conservative temperature and absolute salinity) and non-conservative (oxygen, silicate, phosphate and nitrate) properties. The distributions of these water masses are investigated with the use of the optimum multi-parameter (OMP) method and mapped out. The Atlantic Ocean is divided into four vertical layers by distinct neutral densities and four zonal layers to guide the identification and characterization. The water masses in the upper layer originate from wintertime subduction and are defined as central waters. Below the upper layer, the intermediate layer consists of three main water masses: Antarctic Intermediate Water (AAIW), Subarctic Intermediate Water (SAIW) and Mediterranean Water (MW). The North Atlantic Deep Water (NADW, divided into its upper and lower components) is the dominating water mass in the deep and overflow layer. The origin of both the upper and lower NADW is the Labrador Sea Water (LSW), the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW). The Antarctic Bottom Water (AABW) is the only natural water mass in the bottom layer, and this water mass is redefined as Northeast Atlantic Bottom Water (NEABW) in the north of the Equator due to the change of key properties, especially silicate. Similar with NADW, two additional water masses, Circumpolar Deep Water (CDW) and Weddell Sea Bottom Water (WSBW), are defined in the Weddell Sea region in order to understand the origin of AABW.

scholarly journals Sensitivity of the N. AEGEAN SEA ecosystem to Black Sea Water inputs

2014 ◽  
Vol 15 (4) ◽  
pp. 790 ◽  
Author(s):  
G. PETIHAKIS ◽  
K. TSIARAS ◽  
G. TRIANTAFYLLOU ◽  
S. KALARONI ◽  
A. POLLANI
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Black Sea ◽  
Sea Water ◽  
Aegean Sea ◽  
Microbial Loop ◽  
Inorganic Nutrients ◽  
The North ◽  
North Aegean Sea ◽  
The Impact

The effect of Black Sea Water (BSW) inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM) (in the inflowing to the Aegean Sea, BSW) appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic). In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain.

scholarly journals Dynamics and Impacting Factors of Ice Regimes in Latvia Inland and Coastal Waters

2016 ◽  
Vol 70 (6) ◽  
pp. 400-408 ◽  
Author(s):  
Māris Kļaviņš ◽  
Zanita Avotniece ◽  
Valērijs Rodinovs
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
North Atlantic ◽  
Sea Water ◽  
Inland Waters ◽  
The North ◽  
The North Atlantic ◽  
Ice Regime ◽  
The Impact

Abstract The sea ice regime is considered to be a sensitive indicator of climate change. This study investigates long-term changes in the ice regimes of the Gulf of Riga along the coast of Latvia in comparison with those of inland waters. The ice regime of the studied region indicates the impact of climate change related to increasing air and sea water temperatures. Ice cover duration on both the sea and inland waters has decreased during recent decades. In addition, long-term records on ice break in the studied region exhibit a pattern of periodic changes in the intensity of ice regime, while trends of the sea ice regime are not consistent between periods of time. Alternating mild and severe winters also occur. The ice regime was shown to be strongly influenced by large-scale atmospheric circulation processes over the North Atlantic, as indicated by close correlation with the North Atlantic Oscillation index.

Modelling the impact of Black Sea water inflow on the North Aegean Sea hydrodynamics

2010 ◽  
Vol 60 (3) ◽  
pp. 585-596 ◽  
Author(s):  
Margarita Tzali ◽  
Sarantis Sofianos ◽  
Anneta Mantziafou ◽  
Nikolaos Skliris
Keyword(s):  
Black Sea ◽  
Sea Water ◽  
Aegean Sea ◽  
Water Inflow ◽  
The North ◽  
North Aegean ◽  
North Aegean Sea ◽  
The Impact

scholarly journals Investigation of model capability in capturing vertical hydrodynamic coastal processes: a case study in the north Adriatic Sea

Ocean Science ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 51-69 ◽  
Author(s):  
W. J. McKiver ◽  
G. Sannino ◽  
F. Braga ◽  
D. Bellafiore
Keyword(s):  
Coastal Zone ◽  
General Circulation ◽  
Adriatic Sea ◽  
Numerical Study ◽  
Coastal Processes ◽  
Dense Water ◽  
The North ◽  
Surface Patterns ◽  
The Impact ◽  
North Adriatic Sea

Abstract. In this work we consider a numerical study of hydrodynamics in the coastal zone using two different models, SHYFEM (shallow water hydrodynamic finite element model) and MITgcm (Massachusetts Institute of Technology general circulation model), to assess their capability to capture the main processes. We focus on the north Adriatic Sea during a strong dense water event that occurred at the beginning of 2012. This serves as an interesting test case to examine both the models strengths and weaknesses, while giving an opportunity to understand how these events affect coastal processes, like upwelling and downwelling, and how they interact with estuarine dynamics. Using the models we examine the impact of setup, surface and lateral boundary treatment, resolution and mixing schemes, as well as assessing the importance of nonhydrostatic dynamics in coastal processes. Both models are able to capture the dense water event, though each displays biases in different regions. The models show large differences in the reproduction of surface patterns, identifying the choice of suitable bulk formulas as a central point for the correct simulation of the thermohaline structure of the coastal zone. Moreover, the different approaches in treating lateral freshwater sources affect the vertical coastal stratification. The results indicate the importance of having high horizontal resolution in the coastal zone, specifically in close proximity to river inputs, in order to reproduce the effect of the complex coastal morphology on the hydrodynamics. A lower resolution offshore is acceptable for the reproduction of the dense water event, even if specific vortical structures are missed. Finally, it is found that nonhydrostatic processes are of little importance for the reproduction of dense water formation in the shelf of the north Adriatic Sea.

scholarly journals Copepod Community Structure in Pre- and Post- Winter Conditions in the Southern Adriatic Sea (NE Mediterranean)

2020 ◽  
Vol 8 (8) ◽  
pp. 567
Author(s):  
Marijana Hure ◽  
Mirna Batistić ◽  
Vedrana Kovačević ◽  
Manuel Bensi ◽  
Rade Garić
Keyword(s):  
Adriatic Sea ◽  
Eastern Mediterranean ◽  
Central Area ◽  
Mesh Size ◽  
Early Spring ◽  
Winter Period ◽  
Late Winter ◽  
Intermediate Water ◽  
Copepod Community ◽  
Winter Conditions

Copepod communities were studied along an east-west transect in the oligotrophic Southern Adriatic Sea. This dynamic region is under the influence of various physical forces, including winter vertical convection, lateral exchanges between coastal and open sea waters, and ingression of water masses of different properties all of which occurred during the investigation periods. Depth-stratified samples were taken with a Nansen net (250 µm mesh size) in pre- and post-winter conditions in 2015/2016. In December, the coastal copepod community was limited over the western flank, while epipelagic waters of the open and eastern waters were characterized by high diversity, low abundances in the central area, and subsurface/upper mesopelagic copepod species. In April, higher abundances were recorded over the entire vertical profile with the surface coastal copepod community present through the entire transect. Higher abundances in the central area during the post-winter period are probably a consequence of late-winter/early spring blooms near the center of the Southern Adriatic. Mesopelagic fauna of both months was characterized by high abundances of Haloptilus longicornis, characteristic species of the eastern Mediterranean, whose larger presence was favored by the cyclonic phase of the North Ionian Gyre and a consequent strong Levantine Intermediate Water ingression.

scholarly journals Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE section (GEOTRACES section GA01)

2020 ◽  
Vol 17 (4) ◽  
pp. 917-943 ◽  
Author(s):  
Manon Tonnard ◽  
Hélène Planquette ◽  
Andrew R. Bowie ◽  
Pier van der Merwe ◽  
Morgane Gallinari ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
Inductively Coupled Plasma ◽  
Sea Water ◽  
North Atlantic Ocean ◽  
Labrador Sea ◽  
Intermediate Water ◽  
The North ◽  
Irminger Sea ◽  
The North Atlantic

Abstract. Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analyzed using a seaFAST-pico™ coupled to an Element XR sector field inductively coupled plasma mass spectrometer (SF-ICP-MS) and provided interesting insights into the Fe sources in this area. Overall, DFe concentrations ranged from 0.09±0.01 to 7.8±0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland, and Newfoundland margins likely due to riverine inputs from the Tagus River, meteoric water inputs, and sedimentary inputs. Deep winter convection occurring the previous winter provided iron-to-nitrate ratios sufficient to sustain phytoplankton growth and lead to relatively elevated DFe concentrations within subsurface waters of the Irminger Sea. Increasing DFe concentrations along the flow path of the Labrador Sea Water were attributed to sedimentary inputs from the Newfoundland Margin. Bottom waters from the Irminger Sea displayed high DFe concentrations likely due to the dissolution of Fe-rich particles in the Denmark Strait Overflow Water and the Polar Intermediate Water. Finally, the nepheloid layers located in the different basins and at the Iberian Margin were found to act as either a source or a sink of DFe depending on the nature of particles, with organic particles likely releasing DFe and Mn particle scavenging DFe.

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