Data from samples collected at four sites experiencing upwelling off the coast of Northern California in May and June of 2019

The primary objective of this study aims to examine and compare the dynamics of phytoplankton blooms at different stages of upwelling. We combined environmental and physiological observations to put together a narrative of phytoplankton community succession. In doing so, we postulate that the four stations sampled represent a mosaic of different stages of relatively early upwelling cycles such that they can be classified as either the initial onset of upwelling (early stage, denoted by E1) in which the subsurface community only recently transitioned to the surface, or the relatively later phases (later stage, denoted by L2, L3, and L4) where the community has just started to build up biomass and is undergoing the "shift-up" response.

Four sites experiencing upwelling were sampled off the coast of Northern California on May 30, 2019 (E1 and L2) and June 05, 2019 (L3 and L4). Seawater was collected using a CTD-Rosette sampler, at four depths throughout the euphotic zone at each station corresponding to 50%, 30%, 10%, and 1% incident irradiance. Samples for temperature, salinity, PAR, chlorophyll a, dissolved inorganic nutrients, dissolved metal micronutrients, and physiology were obtained. PUPCYCLE I (Phytoplankton response to the UPwelling CYCLE) took place in summer 2019 onboard the R/V Oceanus (OC 1905b), led by Chief Scientist Adrian Marchetti.