Enhanced role of eddies in the Arctic marine biological pump

Watanabe, Eiji; Onodera, Jonaotaro; Harada, Naomi; Honda, Makio C.; Kimoto, Katsunori; Kikuchi, Takashi; Nishino, Shigeto; Matsuno, Kohei; Yamaguchi, Atsushi; Ishida, Akio; Kishi, Michio J.

doi:10.1038/ncomms4950

Cited by 96 publications

(140 citation statements)

References 46 publications

Supporting

Mentioning

133

Contrasting

Order By: Relevance

“…The difference in chlorite and sedimentation rate records between 01A-GC and 05JPC/06JPC may be related to either (1) variable sediment focusing at different water depths or (2) redistribution of the BSI water between different branches after passing the Bering Strait. (1) A sediment-trap study demonstrated that shelf-break eddies in winter are important to carry fine-grained lithogenic material from the Chukchi shelf to the slope areas (Watanabe et al, 2014). This redeposition process may have weakened the BSI signal in slope sediments of 05JPC/06JPC compared with outer-shelf sediments of 01A-GC.…”

Section: Holocene Changes In the Bering Strait Inflowmentioning

confidence: 99%

Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

et al. 2017

View full text Add to dashboard Cite

Abstract. The Beaufort Gyre (BG) and the Bering Strait inflow (BSI) are important elements of the Arctic Ocean circulation system and major controls on the distribution of Arctic sea ice. We report records of the quartz / feldspar and chlorite / illite ratios in three sediment cores from the northern Chukchi Sea, providing insights into the long-term dynamics of the BG circulation and the BSI during the Holocene. The quartz / feldspar ratio, interpreted as a proxy of the BG strength, gradually decreased during the Holocene, suggesting a long-term decline in the BG strength, consistent with an orbitally controlled decrease in summer insolation. We propose that the BG rotation weakened as a result of the increasing stability of sea-ice cover at the margins of the Canada Basin, driven by decreasing insolation. Millennial to multi-centennial variability in the quartz / feldspar ratio (the BG circulation) is consistent with fluctuations in solar irradiance, suggesting that solar activity affected the BG strength on these timescales. The BSI approximation by the chlorite / illite record, despite a considerable geographic variability, consistently shows intensified flow from the Bering Sea to the Arctic during the middle Holocene, which is attributed primarily to the effect of higher atmospheric pressure over the Aleutian Basin. The intensified BSI was associated with decrease in sea-ice concentrations and increase in marine production, as indicated by biomarker concentrations, suggesting a major influence of the BSI on sea-ice and biological conditions in the Chukchi Sea. Multi-century to millennial fluctuations, presumably controlled by solar activity, were also identified in a proxy-based BSI record characterized by the highest age resolution.

show abstract

Section: Holocene Changes In the Bering Strait Inflowmentioning

confidence: 99%

Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Submesoscale physical features are especially important to biogeochemical processes affecting the horizontal and vertical distribution of nutrients and phytoplankton biomass [Watanabe et al, 2014]. Most of the participating models are developed on global scales and only four of them are regional models of the order of 10 km resolution (Table 1).…”

Section: 1002/2016jc011993mentioning

confidence: 99%

Net primary productivity estimates and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models

Lee

Matrai

Friedrichs

et al. 2016

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

The relative skill of 21 regional and global biogeochemical models was assessed in terms of how well the models reproduced observed net primary productivity (NPP) and environmental variables such as nitrate concentration (NO3), mixed layer depth (MLD), euphotic layer depth (Zeu), and sea ice concentration, by comparing results against a newly updated, quality‐controlled in situ NPP database for the Arctic Ocean (1959–2011). The models broadly captured the spatial features of integrated NPP (iNPP) on a pan‐Arctic scale. Most models underestimated iNPP by varying degrees in spite of overestimating surface NO3, MLD, and Zeu throughout the regions. Among the models, iNPP exhibited little difference over sea ice condition (ice‐free versus ice‐influenced) and bottom depth (shelf versus deep ocean). The models performed relatively well for the most recent decade and toward the end of Arctic summer. In the Barents and Greenland Seas, regional model skill of surface NO3 was best associated with how well MLD was reproduced. Regionally, iNPP was relatively well simulated in the Beaufort Sea and the central Arctic Basin, where in situ NPP is low and nutrients are mostly depleted. Models performed less well at simulating iNPP in the Greenland and Chukchi Seas, despite the higher model skill in MLD and sea ice concentration, respectively. iNPP model skill was constrained by different factors in different Arctic Ocean regions. Our study suggests that better parameterization of biological and ecological microbial rates (phytoplankton growth and zooplankton grazing) are needed for improved Arctic Ocean biogeochemical modeling.

show abstract

“…1). Early-winter maxima of sinking particle flux with fresh organic material have been captured annually at Station NAP (75 • N, 162 • W, 1975 m water depth) (Watanabe et al, 2014;. The substantial quantities of lithogenic minerals in the trapped particles suggest shelf-origin water transport toward the NAP region.…”

Section: E Watanabe Et Al: Wind-driven Interannual Variability Of Smentioning

confidence: 96%

“…Further detailed investigation of the background mechanisms associated with summer biogenic flux would be highly valuable and possible using a coupled physical and marine ecosystem model. Whereas the main content of observed diatom valves was the sea ice-related species (e.g., Fossula arctica, , the sea ice ecosystem was not included in our previous model experiment (Watanabe et al, 2014). The lack of ice algae was a plausible factor for the summer delay of the simulated biogenic flux peak behind the trap data.…”

Section: E Watanabe Et Al: Wind-driven Interannual Variability Of Smentioning

confidence: 96%

“…The substantial quantities of lithogenic minerals in the trapped particles suggest shelf-origin water transport toward the NAP region. Seasonal experiments using an eddy-resolving (5 km grid size) pan-Arctic sea ice-ocean model indicated the effective role of Beaufort shelf-break eddies in the transport of Chukchi shelf water with high biological productivity and in the consequent early-winter peaks of sinking biogenic flux at Station NAP (Watanabe et al, 2014). It should be noted that biological production continued inside these eddies moving in the southern Canada Basin.…”

Section: E Watanabe Et Al: Wind-driven Interannual Variability Of Smentioning

confidence: 99%

See 1 more Smart Citation

Wind-driven interannual variability of sea ice algal production in the western Arctic Chukchi Borderland

et al. 2015

View full text Add to dashboard Cite

Abstract. Seasonal and interannual variability in the biogenic particle sinking flux was recorded using multi-year bottom-tethered sediment trap mooring systems in the Northwind Abyssal Plain (Station NAP: 75 • N, 162 • W, 1975 m water depth) of the western Arctic Chukchi Borderland. Trapped particle flux at a median depth of 184 m had an obvious peak and dominance of sea ice-related diatom assemblages in August 2011. The observed particle flux was considerably suppressed throughout summer 2012. In the present study, the response of ice algal production and biomass to wind-driven changes in the physical environment was addressed using a pan-Arctic sea ice-ocean modeling approach. A sea ice ecosystem with ice algae was newly incorporated into the lower-trophic marine ecosystem model, which was previously coupled with a high-resolution (i.e., 5 km horizontal grid size) sea ice-ocean general circulation model. Seasonal model experiments covering 2-year mooring periods indicated that primary productivity of ice algae around the Chukchi Borderland depended on basin-scale wind patterns via various processes. Easterly winds in the southern part of a distinct Beaufort High supplied nutrientrich water for euphotic zones of the NAP region via both surface Ekman transport of Chukchi shelf water and vertical turbulent mixing with underlying nutricline water in 2011. In contrast, northwesterly winds flowing in the northern part of an extended Siberian High transported oligotrophic water within the Beaufort Gyre circulation toward the NAP region in 2012. The modeled ice algal biomass during summer reflected the differences in nutrient distribution. The modeled sinking flux of particulate organic nitrogen (PON) was comparable with the time series obtained from sediment trap data in summer 2011. In contrast, lateral advection of ice algal patches of shelf origin during a great cyclone event may have caused a modeled PON flux bias in 2012. Sensitivity experiments revealed several uncertainties of model configurations of ice algal productivity, particle sinking speed, and grazing activities. Extending the year-long measurements is expected to help illustrate the more general features of ice-related biological processes in the Arctic Ocean.

show abstract

Enhanced role of eddies in the Arctic marine biological pump

Cited by 96 publications

References 46 publications

Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

Holocene dynamics in the Bering Strait inflow to the Arctic and the Beaufort Gyre circulation based on sedimentary records from the Chukchi Sea

Net primary productivity estimates and environmental variables in the Arctic Ocean: An assessment of coupled physical-biogeochemical models

Wind-driven interannual variability of sea ice algal production in the western Arctic Chukchi Borderland

Contact Info

Product

Resources

About