Water masses and circulation in the central region of the Eastern Mediterranean: Eastern Ionian, South Aegean and Northwest Levantine, 1986–1987

Theocharis, Alexander; Georgopoulos, Dimitris; Lascaratos, A.; Nittis, K.

doi:10.1016/0967-0645(93)90064-t

Cited by 176 publications

(142 citation statements)

References 10 publications

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“…Water masses from the northwest Levantine also enter the Cretan Sea at intermediate depths (Levantine Intermediate Water-LIW) following the same LSW pathways through the eastern Cretan Straits [Theocharis et al, 1993] although Astraldi et al, [1999] have reported that some minor LIW masses also enter through [Zodiatis, 1991b]. However, it was not until Schlitzer et al [1991] named these intermediate masses of Cretan Sea origin as Cretan Intermediate Water (CIW) that they were identified as a distinguishable water mass.…”

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

“…It is traced as a surface/subsurface salinity minimum (S 38.5-38.9) at depths of up to 100 dbars. Less saline AW is found at the western entrance of the Cretan Sea fed directly by the AW carrying, Atlantic-Ionian Stream (AIS) [Zodiatis, 1991a[Zodiatis, , 1991bTheocharis et al, 1993Theocharis et al, , 1999a. After its entrance, AW mass is traced up to the central part of the Cretan basin, mainly in the summer period as winter convective mixing destroys the low salinity signal.…”

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

“…BSW follows a general cyclonic path in the North and Central Aegean and finally enters the South Aegean through the western part of the Cyclades plateau [Zodiatis, 1991a[Zodiatis, , 1993Theocharis et al, 1993Theocharis et al, , 1999aGertman et al, 2006;Velaoras and Lascaratos, 2010]. At the time BSW reaches the Cretan Sea, it has significantly increased its salt content through mixing with surface Aegean masses and is traced in the western part of Cretan Sea up to the western straits as a low salinity surface/subsurface signal (S 38.9).…”

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

“…After entering the Cretan Sea, LSW bifurcates. One branch feeds the Cretan Sea moving westward and a second one moves towards the north, supplying LSW to the Central Aegean [Zodiatis, 1991b[Zodiatis, , 1993Theocharis et al, 1993].…”

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

“…It exchanges water masses of different origins with adjoining basins (the Ionian, Levantine, and North-Central Aegean Seas) [Theocharis et al, 1993]. Moreover, the Cretan Sea is an active intermediate and occasionally deep water mass source.…”

Section: Introductionmentioning

confidence: 99%

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Dense intermediate water outflow from the Cretan Sea: A salinity driven, recurrent phenomenon, connected to thermohaline circulation changes

et al. 2014

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Data collected from different platforms in the Cretan Sea during the 2000s decade present evidence of gradually increasing salinity in the intermediate and deep intermediate layers after the middle of the decade. The observed gradual salt transport toward the deeper layers indicates contributions of dense water masses formed in various Aegean Sea subbasins. The accumulation of these saline and dense water masses in the Cretan Sea finally led to outflow from both Cretan Straits, with density greater than typical Levantine/Cretan Intermediate water but not dense enough to penetrate into the deep layers of the Eastern Mediterranean. We name this outflowing water mass as dense Cretan Intermediate Water (dCIW). A retrospective analysis of in situ data and literature references during the last four decades shows that similar events have occurred in the past in two occasions: (a) in the 1970s and (b) during the Eastern Mediterranean Transient (EMT) onset (1987)(1988)(1989)(1990)(1991). We argue that these salinity-driven Aegean outflows are mostly attributed to recurrent changes of the Eastern Mediterranean upper thermohaline circulation that create favorable dense water formation conditions in the Aegean Sea through salinity preconditioning. We identify these phenomena as ''EMT-like'' events and argue that in these cases internal thermohaline mechanisms dominate over atmospheric forcing in dense water production. However, intense atmospheric forcing over an already salinity preconditioned basin is indispensable for creating massive deep water outflow from the Cretan Sea, such as the EMT event.

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Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

Section: Surface and Intermediate Masses And Circulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dense intermediate water outflow from the Cretan Sea: A salinity driven, recurrent phenomenon, connected to thermohaline circulation changes

et al. 2014

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Long‐lived mesoscale eddies in the eastern Mediterranean Sea: Analysis of 20 years of AVISO geostrophic velocities

et al. 2014

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We analyzed 20 years of AVISO data set to detect and characterize long-lived eddies, which stay coherent more than 6 months, in the eastern Mediterranean Sea. In order to process the coarse gridded (1=8 ) AVISO geostrophic velocity fields, we optimized a geometrical eddy detection algorithm. Our main contribution was to implement a new procedure based on the computation of the Local and Normalized Angular Momentum (LNAM) to identify the positions of the eddy centers and to follow their Lagrangian trajectories. We verify on two mesoscale anticyclones, sampled during the EGYPT campaign in 2006, that our methodology provides a correct estimation of the eddy centers and their characteristic radius corresponding to the maximal tangential velocity. Our analysis reveals the dominance of anticyclones among the longlived eddies. This cyclone-anticyclone asymmetry appears to be much more pronounced in eastern Mediterranean Sea than in the global ocean. Then we focus our study on the formation areas of long-lived eddies. We confirm that the generations of the Ierapetra and the Pelops anticyclones are recurrent and correlated to the Etesian wind forcing. We also provide some evidence that the smaller cyclonic eddies formed at the southwest of Crete may also be induced by the same wind forcing. On the other hand, the generation of long-lived eddies along the Libyo-Egyptian coast are not correlated to the local wind-stress curl but surprisingly, their initial formation points follow the Herodotus Trough bathymetry. Moreover, we identify a new formation area, not discussed before, along the curved shelf off Benghazi.

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Dynamical Evolution of Intense Ierapetra Eddies on a 22 Year Long Period

Ioannou

Stegner

et al. 2017

JGR Oceans

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Considered as wind forced, the recurrent formation of Ierapetra eddy affects the Eastern Mediterranean Sea circulation. Even though this large, coherent, and long‐lived anticyclone has been extensively studied, there are only few quantitative information on its dynamical characteristics. The main goal of this study is to quantify the Ierapetra eddies (IEs) intensity and examine their seasonal and interannual variability over a 22 year period (1993–2014). We choose the automatic eddy detection algorithm AMEDA to estimate the main IEs dynamical parameters such as their size, their intensities, and their lifetimes. Applied to daily AVISO altimetric products, the AMEDA allows a full eddy characterization providing additional information on vortex velocity profiles as well as on merging and splitting events. Among the years of observations, the IEs Rossby number experience a strong variability and could vary by a factor 4 (Ro = 0.07–0.27). This is mainly due to the eddy velocity variations rather than size variations. Moreover, we found that after their formation IEs could reintensify. This intensification process may lead to a doubling of the vortex intensity in less than 4 months. That extra input of energy coincides with the Etesian winds period. Such high intensities are not expected from large‐scale anticyclones and require cyclogeostrophic corrections. Considering this ageostrophic part, the maximum values of the core vorticity were derived and we found that the IEs might sometimes exhibit a negative potential vorticity core. Evidences on the eddy intensity from two oceanographic campaigns suggest that the IEs are probably more intense than we even estimate.

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Water masses and circulation in the central region of the Eastern Mediterranean: Eastern Ionian, South Aegean and Northwest Levantine, 1986–1987

Cited by 176 publications

References 10 publications

Dense intermediate water outflow from the Cretan Sea: A salinity driven, recurrent phenomenon, connected to thermohaline circulation changes

Dense intermediate water outflow from the Cretan Sea: A salinity driven, recurrent phenomenon, connected to thermohaline circulation changes

Long‐lived mesoscale eddies in the eastern Mediterranean Sea: Analysis of 20 years of AVISO geostrophic velocities

Dynamical Evolution of Intense Ierapetra Eddies on a 22 Year Long Period

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