Song, XK; Gu, YZ; Zhai, FG; Li, PL; Liu, PX; Liu, ZZ; Wu, WF; Chen, YZ; Jiang, XY; He, JL (2020). Climatology and seasonal variability of satellite-derived chlorophyll a around the Shandong Peninsula. JOURNAL OF OCEANOLOGY AND LIMNOLOGY.

The chlorophyll a (Chl a) is an important indicator of marine ecosystems. The spatiotemporal variation of the Chl a greatly affects the mariculture and marine ranching in coastal waters of the Shandong Peninsula. In the current study, the climatology and seasonal variability of surface Chl-a concentration around the Shandong Peninsula are investigated based on 16 years (December 2002-November 2018) of satellite observations. The results indicate that the annual mean Chl-a concentration is greater in the Bohai Sea than in the Yellow Sea and decreases from coastal waters to offshore waters. The highest Chl-a concentrations are found in Laizhou Bay (4.2-8.0 mg/m(3)), Haizhou Bay (4.2-5.9 mg/m(3)) and the northeast coast of the Shandong Peninsula (4.4-5.0 mg/m(3)), resulting from the combined effects of the intense riverine input and long residence time caused by the concave shape of the coastline. The seasonal Chl-a concentration shows a significant spatial variation. The Chl-a concentrations in these three subregions generally exhibit an annual maximum in August/September, due to the combined effects of sea surface temperature, river discharge and sea surface wind. In the southeast coast region, however, the Chl-a concentration is lowest throughout the year and reaches a maximum in February with a minimum in July, forced by the seasonal evolution of the Yellow Sea Cold Water and monsoon winds. The interannual Chl-a concentration trends vary among regions and seasons. There are significant increasing trends over a large area around Haizhou Bay from winter to summer, which are mainly caused by the rising sea surface temperature and eutrophication. In other coastal areas, the Chl-a concentration shows decreasing trends, which are clearest in summer and induced by the weakening land rainfall. This study highlights the differences in the Chl-a dynamics among regions around the Shandong Peninsula and is helpful for further studies of coupled physical-ecological-human interactions at multiple scales.