scholarly journals Tentative study of flow patterns in the North Aegean Sea using NOAA-AVHRR images and 2D model simulation

1996 ◽  
Vol 14 (11) ◽  
pp. 1221 ◽  
Author(s):  
G. Zodiatis ◽  
S. Alexandri ◽  
P. Pavlakis ◽  
L. Jonsson ◽  
G. Kallos ◽  
...  
1996 ◽  
Vol 14 (11) ◽  
pp. 1221-1231 ◽  
Author(s):  
G. Zodiatis ◽  
S. Alexandri ◽  
P. Pavlakis ◽  
L. Jonsson ◽  
G. Kallos ◽  
...  

Abstract. A statistical technique for image processing, the maximum cross correlation (MCC) method, was utilized on sequences of NOAA-AVHRR thermal data in order to explore the surface advective current dynamics at the discharge region of the Hellespont in the North Aegean Sea. A 2D numerical flow model was also used in order to simulate the barotropic flow pattern of the surface water layer. The model was forced with diurnal wind fields obtained for the same period as the satellite infrared images. The currents (magnitude and direction) derived from the two methods compare satisfactorily despite the fact that some model simplifications were made.


2002 ◽  
Vol 46 (8) ◽  
pp. 195-202 ◽  
Author(s):  
L. Jönsson

Satellite data from the SeaWiFS sensor has been used to determine chlorophyll-a contents in the North Aegean Sea using SEADAS 3.3 software. The data is used to extract knowledge on water movements/flow phenomena using chlorophyll as a “tracer” but will also indicate water quality. More than 100 SeaWiFS scenes from 1998 up to 2001 have been analyzed in terms of hydrodynamic phenomena, mainly the transport and spreading pattern of Black Sea Water in the North Aegean Sea but also concerning the water quality and its seasonal and yearly variation at the mouth region of the Dardanelles. Some comparison with earlier studies using NOAA AVHRR thermal data and historical CZCS scenes is also made.


Author(s):  
Ilias Lazos ◽  
Sotirios Sboras ◽  
Christos Pikridas ◽  
Spyros Pavlides ◽  
Alexandros Chatzipetros

2021 ◽  
Vol 22 (3) ◽  
pp. 653
Author(s):  
ATHANASIOS GKANASOS ◽  
EUDOXIA SCHISMENOU ◽  
KOSTAS TSIARAS ◽  
STYLIANOS SOMARAKIS ◽  
MARIANNA GIANNOULAKI ◽  
...  

We present the development of a 3D full-lifecycle, individual-based model (IBM) for anchovy and sardine, online coupled to an existing hydrodynamic/biogeochemical low-trophic level (LTL) model for the North Aegean Sea. It was built upon an existing 1D model for the same species and area, with the addition of a horizontal movement scheme. In the model, both species evolve from the embryonic stage (egg+yolk sac larva) to the larval, juvenile, and adult stages. Somatic growth is simulated with the use of a “Wisconsin” type bioenergetics model and fish populations with an adaptation of the ‘super individuals’ (SI) approach. For the reference simulation and model calibration, in terms of fish growth and population biomass, the 2000-2010 period was selected. Interannual biomass variability of anchovy was successfully represented by the model, while the simulated biomass of sardine exhibited low variability and did not satisfactorily reproduce the observed interannual variability from acoustic surveys. The spatial distribution of both species’ biomass was in relatively good agreement with field data. Additional single-species simulations revealed that species compete for food resources. Temperature sensitivity experiments showed that both species reacted negatively to a temperature increase. Anchovy, in particular, was more affected since its spawning and larval growth periods largely overlap with the period of maximum yearly temperature and low prey concentration. Finally, simulation experiments using IPCC climatic scenarios showed that the predicted temperature increase and zooplankton concentration decrease in the future will negatively affect anchovy, resulting in sardine prevalence.


1987 ◽  
Vol 24 (2) ◽  
pp. 265-278 ◽  
Author(s):  
H.E. Voultsiadou-Koukoura ◽  
A. Koukouras ◽  
A. Eleftheriou

2014 ◽  
Vol 19 (1) ◽  
pp. 273-273
Author(s):  
Athanassios Ganas ◽  
Zafeiria Roumelioti ◽  
Vassilios Karastathis ◽  
Konstantinos Chousianitis ◽  
Alexandra Moshou ◽  
...  

2017 ◽  
Vol 149 ◽  
pp. 138-150 ◽  
Author(s):  
B.-Th. Karatsolis ◽  
M.V. Triantaphyllou ◽  
M.D. Dimiza ◽  
E. Malinverno ◽  
A. Lagaria ◽  
...  

PLoS ONE ◽  
2019 ◽  
Vol 14 (8) ◽  
pp. e0219671 ◽  
Author(s):  
Athanasios Gkanasos ◽  
Stylianos Somarakis ◽  
Kostas Tsiaras ◽  
Dimitrios Kleftogiannis ◽  
Marianna Giannoulaki ◽  
...  

2019 ◽  
Vol 11 (3) ◽  
pp. 680 ◽  
Author(s):  
Sofia Karampela ◽  
George Papapanos ◽  
Thanasis Kizos

The lack of understanding and definitional inconsistencies regarding agritourism and the importance of cooperation in sustaining this kind of tourism are underlined in the literature. This study analyzes the perceptions of agritourism and cooperation from actors in the sector using a plurality of methods, including unsupervised (a) text mining and (b) sentiment analysis with the use of a lexical database, as well as (c) supervised qualitative data analysis. Based on the assumption that destinations with different geographic characteristics have different features and products, two different destinations as for its accessibility and tourism recognition were selected for comparison: (a) an island—Lesvos in the North Aegean Sea, and (b) a continental mountain region—Plastiras Lake, in Greece. The data were collected from personal in-depth interviews and with the use of semi-structured questionnaires. From a methodological perspective, all three methods provided unique insights on the study’s themes, and the overall image of agritourism and cooperation was positive. A common understanding seems important for cooperation and networking; however, training is needed not only for effective promotion of agritourism, but also for cooperation techniques, benefits, trust-building mechanisms and best practices.


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