caa a22 4500 605455368 CHVBK 20210128100212.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10872-015-0290-8 doi (NATIONALLICENCE)springer-10.1007/s10872-015-0290-8 POC fluxes estimated from 234Th in late spring-early summer in the western subarctic North Pacific [Elektronische Daten] [Hajime Kawakami, Makio Honda, Kazuhiko Matsumoto, Masahide Wakita, Minoru Kitamura, Tetsuichi Fujiki, Shuichi Watanabe] Measurements of 234Th, particulate organic carbon (POC), nutrients and net primary production were made at station K2 (47°N, 160°E) in the western subarctic North Pacific Ocean six times from 3 June to 17 July 2006. Net primary productions varied from 263 to 732 mgC m−2 d−1. 234Th was used as a tracer to estimate POC fluxes from the surface layer to 100m depth. POC fluxes varied from 14 to 284 mgCm−2d−1. The maximum POC flux and net primary production in this study were much higher than those observed previously at station K2 (179 mgCm−2d−1 in July 2003 for POC flux, 552 mgCm−2d−1 in May 2004 for net primary production). Because maximum chlorophyll a in this study (1.3µg L−1) was also much higher than previous values at station K2 (1.0µg L−1 in August 2004), we assumed that high-frequency observations had allowed measurement of a near annual peak of biological production and biological pump activity. The net primary productions and POC fluxes changed greatly during the study period. Biological production and export in this region varied greatly during this season. The export ratio (POC flux/net primary production) in this season (23±1%) was less than the annual export ratio in this region (29±1% in 2002-2005), although this ratio was higher than those in the other oceans (5-10%). POC export (5.0±0.1gCm−2) in late spring-early summer was about half that of net community production (10.2±0.6gCm−2) estimated from the drawdown of phosphate during the study period. We suggest that the pathways of carbon export, other than the sinking of particles, were transport by zooplankton and so on. The Oceanographic Society of Japan and Springer Japan, 2015 Biological pump nationallicence 234Th nationallicence POC flux nationallicence High-frequency observations nationallicence Western subarctic North Pacific nationallicence Kawakami Hajime Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut Honda Makio Department of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut Matsumoto Kazuhiko Department of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut Wakita Masahide Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut Kitamura Minoru Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut Fujiki Tetsuichi Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut Watanabe Shuichi Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut Journal of Oceanography Springer Japan 71/3(2015-06-01), 311-324 0916-8370 71:3<311 2015 71 10872 https://doi.org/10.1007/s10872-015-0290-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10872-015-0290-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kawakami Hajime Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut NATIONALLICENCE 700 1- Honda Makio Department of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut NATIONALLICENCE 700 1- Matsumoto Kazuhiko Department of Environmental Geochemical Cycle Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut NATIONALLICENCE 700 1- Wakita Masahide Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut NATIONALLICENCE 700 1- Kitamura Minoru Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut NATIONALLICENCE 700 1- Fujiki Tetsuichi Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, 237-0061, Yokosuka, Japan aut NATIONALLICENCE 700 1- Watanabe Shuichi Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Aza-kitasekine, Oaza-sekine, 035-0022, Mutsu, Japan aut NATIONALLICENCE 773 0- Journal of Oceanography Springer Japan 71/3(2015-06-01), 311-324 0916-8370 71:3<311 2015 71 10872