Variability of mesoscale features in the Mediterranean Sea from XBT data analysis

Abstract

Abstract. During the period 1998–2000, the Mediterranean Forecasting System Pilot Project, aiming to build a forecasting system for the physical state of the sea, has been carried out. A ship-of-opportunity programme sampled the Mediterranean upper ocean thermal structure by means of eXpendable Bathy-Thermographs (XBTs), along seven tracks, from September 1999 to May 2000. The tracks were designed to detect some of the main circulation features, such as the stream of surface Atlantic water flowing from the Alboran Sea to the Eastern Levantine Basin. The cyclonic gyres in the Liguro-Provenal Basin, the southern Adriatic and Ionian Seas and the anticyclonic gyres in the Levantine Basin were also features to be detected. The monitoring system confirmed a long-term persistence of structures (at least during the entire observing period), which were previously thought to be transient features. In particular, in the Levantine Basin anticyclonic Shikmona and Ierapetra Gyres have been observed during the monitoring period. In order to identify the major changes in the thermal structures and the dynamical implications, the XBT data are compared with historical measurements collected in the 1980s and 1990s. The results indicate that some thermal features are being restored to the situation that existed in the 1980s, after the changes induced by the so-called "Eastern Mediterranean Transient". Key words. Oceanography: physical (eddies and mesoscale processes; general circulation; instruments and techniques)

Temporal evolution of thermal structures and winter heat content change from VOS-XBT data in the central Mediterranean Sea

“…The other one is much better indicated by a slope of the isolines at its northernmost end. The assertion of the presence of this northern cyclonic gyre is corroborated by a trajectory of a PALACE float released in the Ionian Sea in March 2000 (available at URL page of the Naval Oceanographic Office, USA, http://flux.ocean.washington.edu), as well as by analysis of the same XBT data in Fusco et al (2003). Malanotte-Rizzoli et al (1997) reported a presence of a "permanent cyclone" during the second half of the 1980's, situated between 37 and 38 • N, near the coast.…”

“…Quality checks, including an assessment of the overall consistency of the data, were performed by Fusco et al (2003).…”

“…The phenomenology and the preliminary overview of the thermal evolution from all XBT data in the Mediterranean upper layer, discussed in relation with previous knowledge, are extensively reported in the paper by Fusco et al (2003).…”

Influence of anticyclonic eddies on the Biogeochemistry from the Oligotrophic to the Ultraoligotrophic Mediterranean (BOUM cruise)

“…1 middle) contour the high levels induced by the three eddies (LD station A in the western MS, LD station B in the Ionian basin between the western and Levantine basins, and LD station C in the Levantine basin of the eastern MS). The well-known Ierapetra anticyclonic eddy (Fusco et al, 2003) located to the south-east of Crete island (near 34 • N, 26 • E) was also traversed, (see ADCP currents, Fig. 1 top), but is weakly signed on absolute topography (Fig.…”

The circulation pattern in the Mediterranean Sea: issues for modeller consideration

“…The Mediterranean Sea is now known to have a very high spatial and temporal variability at all scales, from small turbulence to basin scale processes. 27 There has been significant modern research on the general circulation within the Mediterranean Sea as well as on its thermohaline pattern and its variability. The identification and qualification of critical processes relevant to ocean and climate dynamics, which involves several issues, has involved numerous researchers and produced a plethora of publications, many of which are directly referenced in this paper and others have been included in the bibliography.…”