TY - JOUR
T1 - Mesoscale ocean fronts enhance carbon export due to gravitational sinking and subduction
AU - Stukel, Michael R.
AU - Aluwihare, Lihini I.
AU - Barbeau, Katherine A.
AU - Chekalyuk, Alexander M.
AU - Goericke, Ralf
AU - Miller, Arthur J.
AU - Ohman, Mark D.
AU - Ruacho, Angel
AU - Song, Hajoon
AU - Stephens, Brandon M.
AU - Landry, Michael R.
PY - 2017/2/7
Y1 - 2017/2/7
N2 - Enhanced vertical carbon transport (gravitational sinking and subduction) at mesoscale ocean fronts may explain the demonstrated imbalance of new production and sinking particle export in coastal upwelling ecosystems. Based on flux assessments from 238U:234Th disequilibrium and sediment traps, we found 2 to 3 times higher rates of gravitational particle export near a deep-water front (305 mg C·m-2·d-1) compared with adjacent water or to mean (nonfrontal) regional conditions. Elevated particle flux at the front wasmechanistically linked to Fe-stressed diatoms and highmesozooplankton fecal pellet production. Using a data assimilative regional ocean model fit to measured conditions, we estimate that an additional ∼225 mg C·m-2·d-1 was exported as subduction of particlerich water at the front, highlighting a transport mechanism that is not captured by sediment traps and is poorly quantified by most models and in situ measurements. Mesoscale fronts may be responsible for over a quarter of total organic carbon sequestration in the California Current and other coastal upwelling ecosystems.
AB - Enhanced vertical carbon transport (gravitational sinking and subduction) at mesoscale ocean fronts may explain the demonstrated imbalance of new production and sinking particle export in coastal upwelling ecosystems. Based on flux assessments from 238U:234Th disequilibrium and sediment traps, we found 2 to 3 times higher rates of gravitational particle export near a deep-water front (305 mg C·m-2·d-1) compared with adjacent water or to mean (nonfrontal) regional conditions. Elevated particle flux at the front wasmechanistically linked to Fe-stressed diatoms and highmesozooplankton fecal pellet production. Using a data assimilative regional ocean model fit to measured conditions, we estimate that an additional ∼225 mg C·m-2·d-1 was exported as subduction of particlerich water at the front, highlighting a transport mechanism that is not captured by sediment traps and is poorly quantified by most models and in situ measurements. Mesoscale fronts may be responsible for over a quarter of total organic carbon sequestration in the California Current and other coastal upwelling ecosystems.
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U2 - 10.1073/pnas.1609435114
DO - 10.1073/pnas.1609435114
M3 - Article
C2 - 28115723
AN - SCOPUS:85011698058
VL - 114
SP - 1252
EP - 1257
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 6
ER -