Satellite-derived phytoplankton biomass and production variability in 2 contrasting coastal areas: off southern California and off northern Baja California

In order to compare phytoplankton biomass (satellite-derived chlorophyll, Chl(sat)) and production (PP), and sea surface temperature (SST) between the regions north and south of the Ensenada Front, time series were generated from satellite imagery for 250-km transects perpendicular to the coast: one off La Jolla (TLJ), southern California (USA), and the other off San Quintin Bay (TSQB), Baja California (Mexico). Moderate Resolution Imaging Spectroradiometer (MODIS) SST and Chlsat monthly composites and PP monthly composites were used for the 2002-2016 period. An "average year" was generated for each transect and each variable as an approximation to the climatology. Data show spatial variation in Chlsat and PP with higher values in the coastal zone (>10.0 mg.m(-3) and >4.0 g C.m(-2).d(-1), respectively) than offshore (similar to 0.1 mg.m(-3) and 0.4 g C.m(-2).d(-1), respectively), while SST showed, in general, minimum values in the coastal zone (similar to 15.0 degrees C) and maxima offshore (similar to 21.0 degrees C). In the coastal zone, Chl(sat) values were higher on TSQB than on TLJ. H offshore waters of TSQB because of the effect of high Chl(sat) plumes coming from Point Conceptiowever, sometimes phytoplankton biomass was higher in the offshore waters of TLJ than in theon into the Southern California Bight. The SST, Chl(sat), and PP variations had clear seasonal and interannual components. Spectral analysis shows that the seasonal component of variation was dominant for the 3 variables. The 2004 central Pacific type of El Nino, the 2014 "Blob", and the 2015-2016 eastern Pacific type of El Nino had very strong effects on phytoplankton biomass and production along both transects. Nevertheless, the effects generally tended to be stronger at TLJ than at TSQB. There are spatial variations in the coastal dynamics of the California Current System, and thus the effects of seasonal and interannual events will not be the same at different geographic locations.