Following the determination of eastward/westward baroclinic transport in the 0/40 m layer along the 25°E meridian transect,

αy can be estimated from the elevation of isopycnals of Δz = 1 m over a distance of Δy = 2500 m, for 1998. Since wy/vg = αy = Δz/Δy, by taking vg = 0.1 m s−1, one obtains a vertical velocity wy = 4 × 10−5 m s−1. Similarly, for the 2001 distribution, with a limited geostrophic velocity vg = 0.05 m s−1 and an isopycnal elevation of Δz = 17 m over a distance of Δy = 56000 m, a reduced vertical velocity of wy = 1.5 × 10−5 m s−1 is induced. Indeed, relative vertical velocity estimations using the above described quasi-geostrophic selleck compound density equation appear to be in accordance with chlorophyll a concentration time series, recorded using SeaWiFS over the Samothraki and Lemnos Plateaus (Groom et al. 2006). The results show that the Samothraki Anticyclone could sustain the presence of increased chlorophyll a concentrations (3–5 mg m−3) in summer 1998 and 1999, when vertical velocity values were higher, as opposed to the lower chlorophyll a concentrations

(0.7–1.0 mg m−3) in summer 2001, under lower convective movement conditions. The variability of surface water masses in the North Aegean Sea was studied utilizing Dabrafenib molecular weight a series of 360 CTD profiles obtained during the summers of 1998–2001. The results depicted the temporal variability of the Black Sea Water (BSW) plume expansion, changes in the characteristics of the BSW-LIW frontal zone, and variations in the location and radius of sub-basin scale hydrographic features (such as the Samothraki Anticyclone). The occurrence of significantly warmer surface water masses over the Thracian Sea and Lemnos Plateau in summer 1999 and 2000 suggested a dependence of North Aegean Sea surface dynamics on Black Sea freshwater inputs and global atmospheric forcing (as ENSO events). Furthermore, the results demonstrated the presence of water of relatively higher salinity at the surface of the Thracian Sea and Lemnos Plateau during the summer of 2001, attributed to strong turbulent

wind mixing along the Turkish Straits and the local meteorological influence over the North Aegean Sea. Under the action of strong southerly winds, the horizontal density gradients across the BSW-LIW frontal zone appear Liothyronine Sodium relaxed and are displaced to the north of Lemnos Island, while under northerly wind stresses, the front returns to its regular position (south of Lemnos Island). Finally, the present work indicated the importance of transient winds on the horizontal expansion/suppression events of the Samothraki Anticyclone, leading to significant convective movements within the system. Analysis of geostrophic currents along the 25° meridian transect showed that the horizontal baroclinic transport varied from 0.02 to 0.1 10−3 Sv, while approximations of the quasi-geostrophic density equation produced vertical convective movement estimates of 1.5–4 10−5 m s−1. The authors wish to thank Captain E.