Program

The biological impacts of 2014 warming blob and 2015 El Niño on California Current System (CCS) were examined by using multiple data sources of sea surface temperature, ocean color, in-situ observations and 3-D physical and biological model (ROMS-CoSiNE). In the north CCS, the anomalous warming was mainly caused by stronger eastward transport of heat in 2014 winter and 2015 spring, but vertical nutrients supplies were positive and thus led to enhanced phytoplankton in 2015 spring. During 2015 fall and winter, stronger poleward transport of heat kept the anomalous warming, transporting more nutrients from the south resulting in higher chlorophyll. In the central CCS, the anomalous warming in 2014 winter was also caused by stronger eastward transport of heat, but the 2015 warming was mainly caused by stronger poleward transport which was accompanied by higher productivity and chlorophyll. In the South CCS, the anomalous warming in 2014 and 2015 was caused by stronger poleward transport of heat, leading to stronger stratification and thus lower phytoplankton.