CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection

Investigating the Nutrient Landscape in a Coastal Upwelling Region and Its Relationship to the Biological Carbon Pump

“…These results were informed by measurements of new production, which show a strong correlation between nitrate, productivity, and export efficiency (Dugdale & Goering, ; Harrison et al, ), and by the consensus view that large phytoplankton in upwelling regions are more likely to sink individually or be consumed by large fecal pellet‐producing mesozooplankton (Michaels & Silver, ; Smayda, ). More recent results, however, have found inverse correlations between primary productivity and export efficiency in the CCE (Kelly et al, ; Stukel et al, ) and other regions including the Southern Ocean, Canary Current, and Gulf of Mexico (Hernández‐León et al, ; Maiti et al, ; Maiti et al, ). Hypothesized reasons for this discrepancy between theory and in situ measurements include offshore advection of communities, temporal lags between production and export, and specific relationships associated with zooplankton and microbes (Henson et al, ; Kelly et al, ; Laws & Maiti, ; Le Moigne et al, ; Plattner et al, ).…”

“…Hence we sampled homogeneous (i.e., nonfrontal) water parcels spanning coastal to offshore conditions (Landry et al, ; Stukel et al, ). On the P1408 (August 2014) and P1604 (April 2016) cruises, our goal was to investigate system responses to anomalous warming associated with the 2014–2015 North Pacific warm anomaly and ensuing El Niño using similar sampling patterns (Kelly et al, ; Morrow et al, ; Nickels & Ohman, ). On the P1106 (June 2011) and P1208 (August 2012) cruises, we sought to determine ecosystem responses to mesoscale fronts and hence conducted cycles within and to either side of strong frontal gradients (de Verneil & Franks, ; Krause et al, ; Stukel et al, ).…”

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

“…Export flux was generated for a 100-km radius around Sta. M using Kelly et al ( 46 ). Carbon content of pulse events and associated leading/lagging variables were calculated for a window spanning the POC flux pulse, and shifted to correspond to the temporal lag with the peak correlation.…”

Investigating Particle Size-Flux Relationships and the Biological Pump Across a Range of Plankton Ecosystem States From Coastal to Oligotrophic

“…Although we used identical methods on all cruises, the research foci of individual cruises varied leading to slightly different sampling strategies. During the P0704, P0810, P1408, and P1604 cruises our goal was to quantify ecosystem variability during El Niño neutral conditions (P0704 and P0810, Landry et al, 2012;Stukel et al, 2013) and during the anomalous 2014 warm conditions in the North Pacific and ensuing El Niño (P1408 and P1604, respectively; Kelly et al, 2018;Nickels and Ohman, 2018). On these cruises we thus sampled over a wide geographic region from water parcels near the Point Conception upwelling center to oligotrophic, offshore regions >400 km from shore.…”