DOI: 10.1029/2018GB006158
论文题名: Drivers of Carbon Export Efficiency in the Global Ocean
作者: Henson S. ; Le Moigne F. ; Giering S.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 7 语种: 英语
英文关键词: 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)
学科: export efficiency
; export flux
; MAREDAT
; remineralization
中文摘要: 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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160157
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Henson S.,Le Moigne F.,Giering S.. Drivers of Carbon Export Efficiency in the Global Ocean[J]. Global Biogeochemical Cycles,2019-01-01,33(7)