The surface Chl a values (Fig. 5b) were very low (o0.1 mg m 3) before mid-September 2009. They started to increase from October 2009, with continuous high values (40.2 mg m 3) from December
2009 to January 2010. Due to heavy cloud cover, Chl a data acquisition from satellite imageries was hampered from August to November 2009, but a peak of Chl a 40.2 mg m 3 was found in October 3th–10th. Another small peak of Chl a (40.15 mg m 3) was found in March 2010