Episodic organic carbon fluxes from surface ocean to abyssal depths during long-term monitoring in NE Pacific

Ignoring temporal fluctuations in the oceanic carbon budget leads to a significant misrepresentation of the cycling of organic matter from production in surface waters to consumption and sequestration in the abyssal ocean. A 29-year time series (1989 to 2017) of particulate organic carbon (POC) fluxes and sea-floor measurements of sediment community oxygen consumption (SCOC) revealed episodic, high-magnitude events over the past 7 years. Time lags between changes in satellite-estimated export flux, POC flux and SCOC varied from 0 to 70 days. A commonly used model to estimate carbon flux through the water column significantly underestimated the measured carbon fluxes by almost 50%. Episodic pulses of organic carbon into the deep sea must be accounted for to balance the oceanic carbon budget.