气候变化领域集成服务门户(CCPortal): Drivers of Carbon Export Efficiency in the Global Ocean

CCPortal

DOI	10.1029/2018GB006158
	Drivers of Carbon Export Efficiency in the Global Ocean
	Henson S.; Le Moigne F.; Giering S.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	891
结束页码	903
卷号	33 期号:7
英文摘要	The export of organic carbon from the surface ocean forms the basis of the biological carbon pump, an important planetary carbon flux. Typically, only a small fraction of primary productivity (PP) is exported (quantified as the export efficiency: export/PP). Here we assemble a global data synthesis to reveal that very high export efficiency occasionally occurs. These events drive an apparent inverse relationship between PP and export efficiency, which is opposite to that typically used in empirical or mechanistic models. At the global scale, we find that low PP, high export efficiency regimes tend to occur when macrozooplankton and bacterial abundance are low. This implies that a decoupling between PP and upper ocean remineralization processes can result in a large fraction of PP being exported, likely as intact cells or phytoplankton-based aggregates. As the proportion of PP being exported declines, macrozooplankton and bacterial abundances rise. High export efficiency, high PP regimes also occur infrequently, possibly associated with nonbiologically mediated export of particles. A similar analysis at a biome scale reveals that the factors affecting export efficiency may be different at regional and global scales. Our results imply that the whole ecosystem structure, rather than just the phytoplankton community, is important in setting export efficiency. Further, the existence of low PP, high export efficiency regimes imply that biogeochemical models that parameterize export efficiency as increasing with PP may underestimate export flux during decoupled periods, such as at the start of the spring bloom. ©2019. The Authors.
英文关键词	export efficiency; export flux; MAREDAT; remineralization
语种	英语
scopus关键词	bacterium; biogeochemical cycle; biological pump; carbon cycle; carbon flux; ecosystem structure; efficiency measurement; global ocean; organic carbon; phytoplankton; primary production; remineralization; upper ocean; zooplankton; Bacteria (microorganisms)
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/129752
作者单位	National Oceanography Center, European Way, Southampton, United Kingdom; GEOMAR Helmholtz Center for Ocean Research Kiel, Kiel, Germany; Now at Mediterranean Institute of Oceanography, UM 110, Aix Marseille Univ., Université de Toulon, CNRS, IRD, Marseille, France
推荐引用方式 GB/T 7714	Henson S.,Le Moigne F.,Giering S.. Drivers of Carbon Export Efficiency in the Global Ocean[J],2019,33(7).
APA	Henson S.,Le Moigne F.,&Giering S..(2019).Drivers of Carbon Export Efficiency in the Global Ocean.Global Biogeochemical Cycles,33(7).
MLA	Henson S.,et al."Drivers of Carbon Export Efficiency in the Global Ocean".Global Biogeochemical Cycles 33.7(2019).