Trends in primary production, sea surface temperature and wind in upwelling systems (1998–2007)

While increasing Chl-a concentrations have been observed in most EBUS, large areas in the Canary upwelling system showed recent decreasing trends in Chl-a, NPP, and meridional wind.

“However, while increasing concentrations of Chl-a have been observed in most EBUS, large areas in the Canary upwelling system showed recent decreasing trends in Chl-a, NPP (based on ocean color models) and meridional wind (Betancort et al., 2020;Demarcq, 2009;Gómez-Letona et al., 2017).”

Subtropical gyres and Eastern Boundary Upwelling Systems exhibit different spatial and temporal trends in SST, Chl-a, NPP, and meridional wind.

“Specific oceanographic areas such as the subtropical gyres and the Eastern Boundary Upwelling Systems (EBUS) exhibit different spatial and temporal trends in SST, Chl-a, NPP, and meridional wind (Demarcq, 2009;Gómez-Letona et al., 2017;Polonsky & Serebrennikov, 2018;Polovina et al., 2008).”

During the last decades, the four major upwelling systems (California, Benguela, Peru, and Canary) have shown an increase in SST.

“During the last decades, the four major upwelling systems (California, Benguela, Peru, and Canary) have shown an increase in SST (Demarcq, 2009;Seabra et al., 2019).”

Several authors found that the Canary upwelling system has decreased in productivity and Chl-a over the last 20 years.

“Several authors found that the Canary upwelling system has decreased in productivity and Chl-a over the last 20 years (Aristegui et al., 2009;Demarcq, 2009;Gomez-Letona et al., 2017;Sambe et al., 2016).”

Demarcq (2009) and Santos et al. (2012) suggest that warming in coastal upwelling areas is limited due to upwelled colder waters.

“Both Demarcq (2009) and Santos et al. (2012) suggest that warming in coastal upwelling areas is limited due to upwelled colder waters.”