Upwelling and high-frequency variability in the Humboldt Archipelago, Coquimbo upwelling system - Temperature and pH

Temperature, oxygen, and pH levels were continuously (each 30 min) measured in the Humboldt Archipelago (29°S) over four months encompassing the winter-spring transition in 2022 under La Niña conditions. The objective of this study was to quantify the frequency, magnitude, and duration of upwelling, as well as the influence of other oceanographic processes operating at the semidiurnal and daily scales. Temperature, oxygen, and pH were measured using HOBO (U26-001 and MX2501) sensors installed at 10 and 30 m depth. Furthermore, a CTD equipped with oxygen, pH, and chlorophyll sensors was deployed from the surface to a depth of 100 m.