Are trends in SST, surface Chlorophyll-a, primary production and wind stress similar or different over the decadal scale in the south-eastern Black Sea?

Abstract

A 10-year time series of in-situ sea surface temperature (SST), chlorophyll-a concentration and wind stress from 2002 to 2011 was used to examine temporal changes in the South-Eastern Black Sea, together with primary production rates (PP) calculated empirically. Satellite-derived SST was used to support the in-situ SST, and showed a good agreement. the yearly averaged trend for in-situ and satellite-derived winter SST revealed a statistically significant warming over the last decade in the region of. interest. Statistically significant correlation between winter NAO and winter averaged SST suggested that winter SST in the South-Eastern Black Sea is influenced by NAO climatic trends. A consistent decrease in wind stress was observed throughout the time series. Inverse relationship between winter averages of SST and wind stress suggested that SST is forced by wind speed. Chl-a and PP fluctuations during the study period revealed that the system is dominated by nanoplankton with some additional contribution from larger species. We concluded that SST in the South-Eastern Black Sea has increased over the decade, whereas the trend in Chl-a and PP rates were not straightforward. Hence, these conditions with respect to other parameters will need to be considered in future studies for the Black Sea ecosystem.