Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO₂/Ar Measurements With N₂O-Based Corrections for Vertical Mixing ...
We present the first field application of a N₂O-based approach to correct for vertical mixing in the estimation of net community production (NCP) from mixed layer O₂ measurements. Using new ship-based observations of N₂O and biological oxygen saturation anomalies (ΔO₂/Ar) from the Subarctic Northeas...
| Main Authors: | , , , |
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| Format: | Text |
| Language: | English |
| Published: |
The University of British Columbia
2018
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.14288/1.0364314 https://doi.library.ubc.ca/10.14288/1.0364314 |
| Summary: | We present the first field application of a N₂O-based approach to correct for vertical mixing in the estimation of net community production (NCP) from mixed layer O₂ measurements. Using new ship-based observations of N₂O and biological oxygen saturation anomalies (ΔO₂/Ar) from the Subarctic Northeast Pacific, we provide refined mixed layer NCP estimates across contrasting hydrographic regimes and a comprehensive assessment of the methodological considerations and limitations of the approach. Increased vertical mixing coefficients at the base of the mixed layer, derived using N₂O measurements, corresponded with periods of heightened wind speed and coastal upwelling. Corrections were most significant in coastal regions where the vertical supply of low-O₂ water can otherwise falsely imply net heterotrophy from negative ΔO₂/Ar measurements. After correcting for the mixing flux, all coastal stations showed autotrophic signatures, with maximum NCP exceeding 100 mmol O₂ m⁻² d⁻¹ in the spring and summer. Vertical ... |
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