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| Martiny, Adam C.; Lomas, Michael W.; Fu, Weiwei; Boyd, Philip W.; Chen, Yuh-ling L.; Cutter, Gregory A.; Ellwood, Michael J.; Furuya, Ken; Hashihama, Fuminori; Kanda, Jota; Karl, David M.; Kodama, Taketoshi; Li, Qian P.; Ma, Jian; Moutin, Thierry; Woodward, E. Malcolm S.; Moore, J. Keith. |
| Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62308/66557.pdf |
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| Ko, Young Ho; Lee, Kitack; Takahashi, Taro; Karl, David M.; Kang, Sung-ho; Lee, Eunil. |
| Accurate estimation of net community production (NCP) in the ocean is important for determining the future trend for carbon dioxide concentrations in the atmosphere and thus for understanding the global carbon cycle and climate change. Most methods for measuring NCP rely on analysis of dissolved fixed inorganic nitrogen species (N), which are believed to be limiting factors for NCP. However, in the vast areas of the ocean gyres only low levels of N are available for phytoplankton during much of the year. In this study the NCP was estimated by summing the seasonal reduction in the concentration of dissolved inorganic carbon (C-T) in the surface mixed layer, corrected for changes associated with salinity variation, net air-sea CO2 flux, horizontal C... |
| Tipo: Text |
Palavras-chave: Net community production; Nitrogen fixation; Seasonal carbon drawdown; Oligotrophic ocean gyre. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00675/78683/80864.pdf |
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| Picheral, Marc; Guidi, Lionel; Stemmann, Lars; Karl, David M.; Iddaoud, Ghizlaine; Gorsky, Gabriel. |
| The Underwater Vision Profiler (UVP) was developed to quantify the vertical distribution of macroscopic particles and zooplankton > 100 mu m in size. The smaller size limit is fixed by optical resolution, whereas the larger size limit is determined by the volume of water illuminated per image. The new fifth generation instrument (UVP5) is compact (30 kg in air) and operates either as a stand-alone instrument with an independent power supply for use on a mooring or free-drifting array, or as a component of a Conductivity, Temperature, and Depth (CTD)-rosette package. Images are recorded at a frequency up to 6 Hz. If the UVP5 is interfaced with a CTD, these images are acquired and analyzed in real time. Images are recorded every 20 cm at the 1 m s(-1)... |
| Tipo: Text |
Palavras-chave: Video plankton recorder; Marine snow; MU-M; Vertical distribution; Aggregate dynamics; In situ; System; Ocean; Flux; Phytoplankton. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00133/24413/22426.pdf |
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