气候变化领域集成服务门户(CCPortal): Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O-Based Corrections for Vertical Mixing

CCPortal

DOI	10.1002/2017GB005792
	Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O-Based Corrections for Vertical Mixing
	Izett R.W.; Manning C.C.; Hamme R.C.; Tortell P.D.
发表日期	2018
ISSN	0886-6236
EISSN	1944-9224
起始页码	326
结束页码	350
卷号	32 期号:3
英文摘要	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 fluxes were lower in off-shelf waters but often contributed more than 50% to corrected NCP. At some oceanic stations, however, the cooccurrence of N2O minima and O2 maxima resulted in biased (overestimated) N2O corrections. Evaluating vertical fluxes in these regions remains a challenge for ship-based studies. Nonetheless, our refined NCP estimates show better coherence with surface chlorophyll, temperature, and mixed layer depth than uncorrected values. Potential mixed layer N2O production introduces some uncertainty in the approach, but errors are likely to be small. Ultimately, this work provides rationale for the adoption of the N2O correction to refine NCP estimates, particularly in coastal waters. ©2018. American Geophysical Union. All Rights Reserved.
英文关键词	biological oceanography; biophysical coupling; gas tracers
语种	英语
scopus关键词	biophysics; correction; estimation method; heterotrophy; mixed layer; nitrogen; oxygen; primary production; saturation; tracer; vertical mixing; Pacific Ocean; Pacific Ocean (Northeast)
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129854
作者单位	Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada; School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada; Botany Department, University of British Columbia, Vancouver, BC, Canada; Peter Wall Institute for Advanced Studies, University of British Columbia, Vancouver, BC, Canada
推荐引用方式 GB/T 7714	Izett R.W.,Manning C.C.,Hamme R.C.,et al. Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O-Based Corrections for Vertical Mixing[J],2018,32(3).
APA	Izett R.W.,Manning C.C.,Hamme R.C.,&Tortell P.D..(2018).Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O-Based Corrections for Vertical Mixing.Global Biogeochemical Cycles,32(3).
MLA	Izett R.W.,et al."Refined Estimates of Net Community Production in the Subarctic Northeast Pacific Derived From ΔO2/Ar Measurements With N2O-Based Corrections for Vertical Mixing".Global Biogeochemical Cycles 32.3(2018).