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Suppressed CO 2 Outgassing by an Enhanced Biological Pump in the Eastern Tropical Pacific
Author(s) -
Kim Hyung Jeek,
Kim TaeWook,
Hyeong Kiseong,
Yeh SangWook,
Park JongYeon,
Yoo Chan Min,
Hwang Jeomshik
Publication year - 2019
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2019jc015287
Subject(s) - outgassing , biological pump , carbon dioxide , carbon cycle , carbon fibers , environmental science , flux (metallurgy) , pacific decadal oscillation , atmosphere (unit) , atmospheric sciences , oceanography , chemistry , pacific ocean , geology , materials science , ecosystem , ecology , meteorology , biology , physics , organic chemistry , composite number , composite material
The Eastern Tropical Pacific (ETP) is the largest oceanic source of carbon dioxide (CO 2 ) to the atmosphere. Sinking particle fluxes at a depth of 4,950 m (50 m above the seafloor) in the ETP were monitored from 2003 to 2013, during which the Pacific decadal oscillation (PDO) shifted from a positive to negative phase. We show a disproportionate increase in the efficiency of the biological pump in this region relative to the increase in primary production that occurred during La Niña years following the shift of the PDO in 2008. Biogenic carbon export from the surface mixed layer was estimated from the observed particulate organic carbon and inorganic carbon fluxes at a depth of 4,950 m and from empirical equations of the vertical attenuation of carbon flux. Enhanced biological carbon export accounted for 2.3–5.5 mol C m –2 year –1 during the La Niña events. Despite a large uncertainty associated with these estimates, we propose that CO 2 outgassing was largely suppressed by an enhanced biological pump during the La Niña events in the negative PDO phase.