Biological conditions in the Coquimbo upwelling system during the year 2023

A series of discrete measurements were obtained on a near-monthly basis in a subtropical upwelling area of the Humboldt Current System during the year 2023. These included temperature, salinity, dissolved oxygen, fluorescence, and pH profiles, as well as measurements of zooplankton biomass and chlorophyll- and particulate organic carbon (POC) concentrations. Chlorophyll-a analysis was carried out using the flurometric method, with a precision of 0.17 mg/m3. POC was measured with an elemental analyzer (0.013 mg C precision). The measurements were conducted under distinct warm events associated with the ENSO dynamic. The objective of this study was to evaluate the influence of remote (ENSO) and upwelling forcing on the intraseasonal variability of zooplankton biomass.