8 °C). HDAC inhibitor The distribution of the SST warming trend in autumn indicates that the core of the northern Tyrrhenian gyre is warming more significantly than is its surroundings. This may indicate that the northern Tyrrhenian gyre is a significant feature, especially in autumn. The LPC sub-basin SST increases zonally from north (Gulf of Lion) to south in winter (12–14 °C) and autumn (16–18.3 °C). In spring and summer, the LPC sub-basin displays a semicircular SST pattern centred on the Gulf of Lion, where the SST is 16.2 °C in spring and 22 °C in summer; the SST increases with distance from the centre,

the maximum SST occurring off the coast of Valencia, Spain, where it reaches 18.3 °C in spring and 25.1 °C in summer. There is a tongue of similar SST between the LPC and Algerian sub-basins; it is well established in spring, summer and autumn, partly reflecting surface water exchange between the two sub-basins. The Gulf of Lion represents the much colder SST over the entire Mediterranean

Sea year, especially in summer, partly due to the effect of the Mistral winds. The Mistral winds are cold, dry and strong north or north-west winds affecting the western Mediterranean coast of south-eastern France (Jiang et al. 2003). In summer, the Mistral winds can rapidly lower the SST. Some significant warming Roscovitine trend eddies spatially distributed over the LPC sub-basin may indicate a potential change in LPC sub-basin water circulation in the near future. The Algerian sub-basin SST increases zonally from north (14 °C) to south (16 °C) in winter. In spring (summer), approximately 80% (70%) of the Algerian sub-basin is in the 18–18.4 °C (24.5–24.9 °C) range. In autumn, approximately 50% (40%) of the Algerian sub-basin is in the 19.5–19.9 °C (18.6–19 °C) range. The Alboran sub-basin SST is significantly affected by the heat exchange with fresh Atlantic water through the Strait of Gibraltar,

while the wind systems over the Alboran sub-basin significantly affect SST variability. The easterly Levanter warm wind is most common in summer, while the westerly Vendaval cold wind is most common in winter enough (Anonymous 1988). The SST over the Alboran Sea displays marked seasonal behaviour. The Alboran sub-basin SST increases from the north-east (15 °C) to the south-west (16 °C) in winter, partly due to the Vendaval wind. In approximately 65% of the Alboran sub-basin, the SST lies in the 16–16.4 °C range in autumn, increasing zonally from north to south and meridionally from west to east. The western Alboran anticyclonic gyre is well formed in summer, supporting the previous arguments of Millot (2005) and Poulain et al. (2012). The core of this gyre (Figures 2f–j) displays more significant warming than do the surrounding areas, most (least) markedly in summer (autumn).