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Author Proshutinsky, A. ; Krishfield, R. ; Toole, J.M. ; Timmermans, M.-L. ; Williams, W. ; Zimmermann, S. ; Yamamoto-Kawai, M. ; Armitage, T.W.K. ; Dukhovskoy, D. ; Golubeva, E. ; Manucharyan, G.E. ; Platov, G. ; Watanabe, E. ; Kikuchi, T. ; Nishino, S. ; Itoh, M. ; Kang, S.-H. ; Cho, K.-H. ; Tateyama, K. ; Zhao, J.
Title Analysis of the Beaufort Gyre Freshwater Content in 2003-2018 Type $loc['typeJournal Article']
Year 2019 Publication Abbreviated Journal J Geophys Res Oceans
Volume 124
Issue 12
Pages
Keywords Arctic Ocean ; Beaufort Gyre ; circulation ; climate change ; freshwater balance ; modeling
Abstract Hydrographic data collected from research cruises, bottom-anchored moorings, drifting Ice-Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of the Arctic Ocean document an increase of more than 6,400 km(3) of liquid freshwater content from 2003 to 2018: a 40% growth relative to the climatology of the 1970s. This fresh water accumulation is shown to result from persistent anticyclonic atmospheric wind forcing (1997-2018) accompanied by sea ice melt, a wind-forced redirection of Mackenzie River discharge from predominantly eastward to westward flow, and a contribution of low salinity waters of Pacific Ocean origin via Bering Strait. Despite significant uncertainties in the different observations, this study has demonstrated the synergistic value of having multiple diverse datasets to obtain a more comprehensive understanding of Beaufort Gyre freshwater content variability. For example, Beaufort Gyre Observational System (BGOS) surveys clearly show the interannual increase in freshwater content, but without satellite or Ice-Tethered Profiler measurements, it is not possible to resolve the seasonal cycle of freshwater content, which in fact is larger than the year-to-year variability, or the more subtle interannual variations.
Address Physical Oceanography Laboratory Ocean University of China, Qingdao China
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9275
ISBN Medium
Area Expedition Conference
Funding strtoupper('3').strtolower('2055432'); strtoupper('P').strtolower('MC7003849')
Approved $loc['no']
Call Number COAPS @ user @
Serial 1097
Permanent link to this record
Author Proshutinsky, A. ; Krishfield, R. ; Toole, J.M. ; Timmermans, M.-L. ; Williams, W. ; Zimmermann, S. ; Yamamoto-Kawai, M. ; Armitage, T.W.K. ; Dukhovskoy, D. ; Golubeva, E. ; Manucharyan, G.E. ; Platov, G. ; Watanabe, E. ; Kikuchi, T. ; Nishino, S. ; Itoh, M. ; Kang, S.-H. ; Cho, K.-H. ; Tateyama, K. ; Zhao, J.
Title Analysis of the Beaufort Gyre Freshwater Content in 2003-2018 Type $loc['typeJournal Article']
Year 2019 Publication Abbreviated Journal J Geophys Res Oceans
Volume 124
Issue 12
Pages 9658-9689
Keywords Arctic Ocean ; Beaufort Gyre ; circulation ; climate change ; freshwater balance ; modeling
Abstract Hydrographic data collected from research cruises, bottom-anchored moorings, drifting Ice-Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of the Arctic Ocean document an increase of more than 6,400 km(3) of liquid freshwater content from 2003 to 2018: a 40% growth relative to the climatology of the 1970s. This fresh water accumulation is shown to result from persistent anticyclonic atmospheric wind forcing (1997-2018) accompanied by sea ice melt, a wind-forced redirection of Mackenzie River discharge from predominantly eastward to westward flow, and a contribution of low salinity waters of Pacific Ocean origin via Bering Strait. Despite significant uncertainties in the different observations, this study has demonstrated the synergistic value of having multiple diverse datasets to obtain a more comprehensive understanding of Beaufort Gyre freshwater content variability. For example, Beaufort Gyre Observational System (BGOS) surveys clearly show the interannual increase in freshwater content, but without satellite or Ice-Tethered Profiler measurements, it is not possible to resolve the seasonal cycle of freshwater content, which in fact is larger than the year-to-year variability, or the more subtle interannual variations.
Address Physical Oceanography Laboratory Ocean University of China, Qingdao China
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9275
ISBN Medium
Area Expedition Conference
Funding strtoupper('3').strtolower('2055432'); strtoupper('P').strtolower('MC7003849')
Approved $loc['no']
Call Number COAPS @ user @
Serial 1102
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Author Rahaman, H. ; Srinivasu, U. ; Panickal, S. ; Durgadoo, J.V. ; Griffies, S.M. ; Ravichandran, M. ; Bozec, A. ; Cherchi, A. ; Voldoire, A. ; Sidorenko, D.. ; Chassignet, E.P. ; Danabasoglu, G. ; Tsujino, H. ; Getzlaff, K. ; Ilicak, M. ; Bentsen, M. ; Long, M.C. ; Fogli, P.G. ; Farneti, R. ; Danilov, S. ; Marsland, S.J. ; Valcke, S. ; Yeager, S.G. ; Wang, Q.
Title An assessment of the Indian Ocean mean state and seasonal cycle in a suite of interannual CORE-II simulations Type $loc['typeJournal Article']
Year 2020 Publication Ocean Modelling Abbreviated Journal Ocean Modelling
Volume 145
Issue Pages
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-5003
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1087
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Author Roberts, M.J. ; Jackson, L.C. ; Roberts, C.D. ; Meccia, V. ; Docquier, D. ; Koenigk, T. ; Ortega, P. ; Moreno‐ ; Chamarro, E. ; Bellucci, A. ; Coward, A. ; Drijfhout, S. ; Exarchou, E. ; Gutjahr, O. ; Hewitt, H. ; Iovino, D. ; Lohmann, K. ; Putrasahan, D. ; Schiemann, R. ; Seddon, J. ; Terray, L. ; Xu, X. ; Zhang, Q. ; Chang, P. ; Yeager, S.G. ; Castruccio, F.S. ; Zhang. C. ; Wu, L.
Title Sensitivity of the Atlantic Meridional Overturning Circulation to Model Resolution in CMIP6 HighResMIP Simulations and Implications for Future Changes Type $loc['typeJournal Article']
Year 2020 Publication Journal of Advances in Modeling Earth Systems Abbreviated Journal J. Adv. Model. Earth Syst.
Volume Issue Pages Accepted
Keywords
Abstract A multi‐model, multi‐resolution ensemble using CMIP6 HighResMIP coupled experiments is used to assess the performance of key aspects of the North Atlantic circulation. The Atlantic Meridional Overturning Circulation (AMOC), and related heat transport, tends to become stronger as ocean model resolution is enhanced, better agreeing with observations at 26.5°N. However for most models the circulation remains too shallow compared to observations, and has a smaller temperature contrast between the northward and southward limbs of the AMOC. These biases cause the northward heat transport to be systematically too low for a given overturning strength. The higher resolution models also tend to have too much deep mixing in the subpolar gyre.
Address
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1109
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Author Rodríguez, E. ; Bourassa, M. ; Chelton, D. ; Farrar, J.T. ; Long, D. ; Perkovic-Martin, D. ; Samelson, R.
Title The Winds and Currents Mission Concept Type $loc['typeJournal Article']
Year 2019 Publication Frontiers in Marine Science Abbreviated Journal Front. Mar. Sci.
Volume 6
Issue Pages
Keywords
Abstract The Winds and Currents Mission (WaCM) is a proposed approach to meet the need identified by the NRC Decadal Survey for the simultaneous measurements of ocean vector winds and currents. WaCM features a Ka-band pencil-beam Doppler scatterometer able to map ocean winds and currents globally. We review the principles behind the WaCM measurement and the requirements driving the mission. We then present an overview of the WaCM observatory and tie its capabilities to other OceanObs reviews and measurement approaches.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-7745
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1063
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Author Shropshire, T. ; Morey, S. L. ; Chassignet, E. P. ; Bozec, A. ; Coles, V.J. ; Landry, M.R. ; Swalethorp, R. ; Zapfe, G. and Stukel, M.R.
Title Quantifying spatiotemporal variability in zooplankton dynamics in the Gulf of Mexico with a physical-biogeochemical model Type $loc['typeJournal Article']
Year 2019 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract Zooplankton play an important role in global biogeochemistry and their secondary production supports valuable fisheries of the world's oceans. Currently, zooplankton abundances cannot be estimated using remote sensing techniques. Hence, coupled physical-biogeochemical models (PBMs) provide an important tool for studying zooplankton on regional and global scales. However, evaluating the accuracy of zooplankton abundance estimates from PBMs has been a major challenge as a result of sparse observations. In this study, we configure a PBM for the Gulf of Mexico (GoM) from 1993�2012 and validate the model against an extensive combination of in situ biomass and rate measurements including total mesozooplankton biomass, size-fractionated mesozooplankton biomass and grazing rates, microzooplankton specific grazing rates, surface chlorophyll, deep chlorophyll maximum depth, phytoplankton specific growth rates, and net primary production. Spatial variability in mesozooplankton biomass climatology observed in a multi-decadal database for the northern GoM is well resolved by the model with a statistically significant (p < 0.01) correlation of 0.90. Mesozooplankton secondary production for the region averaged 66 + 8 mt C yr−1 equivalent to approximately 10 % of NPP and ranged from 51 to 82 mt C yr−1. In terms of diet, model results from the shelf regions suggest that herbivory is the dominant feeding mode for small mesozooplankton (< 1-mm) whereas larger mesozooplankton are primarily carnivorous. However, in open-ocean, oligotrophic regions, both groups of mesozooplankton have proportionally greater reliance on heterotrophic protists as a food source. This highlights the important role of microbial and protistan food webs in sustaining mesozooplankton biomass in the GoM which serves as the primary food source for early life stages of many commercially-important fish species, including tuna.
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Language Summary Language Original Title
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ISSN ISBN Medium
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Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1095
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Author Stukel, M.R. ; Barbeau, K.A.
Title Investigating the Nutrient Landscape in a Coastal Upwelling Region and Its Relationship to the Biological Carbon Pump Type $loc['typeJournal Article']
Year 2020 Publication Geophysical Research Letters Abbreviated Journal Geophys. Res. Lett.
Volume 47
Issue 6
Pages e2020GL087351
Keywords
Abstract We investigated nutrient patterns and their relationship to vertical carbon export using results from 38 Lagrangian experiments in the California Current Ecosystem. The dominant mode of variability reflected onshore-offshore nutrient gradients. A secondary mode of variability was correlated with silica excess and dissolved iron and likely reflects regional patterns of iron-limitation. The biological carbon pump was enhanced in high nutrient and Fe-stressed regions. Patterns in the nutrient landscape proved to be better predictors of the vertical flux of sinking particles than contemporaneous measurements of net primary production. Our results suggest an important role for Fe-stressed diatoms in vertical carbon flux. They also suggest that either preferential recycling of N or non-Redfieldian nutrient uptake by diatoms may lead to high PO:NO and Si(OH):NO ratios, following export of P- and Si-enriched organic matter. Increased export following Fe-stress may partially explain inverse relationships between net primary productivity and export efficiency.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0094-8276
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1112
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Author Stukel, M.R. ; Ohman, M.D. ; Kelly, T.B. ; Biard, T.
Title The Roles of Suspension-Feeding and Flux-Feeding Zooplankton as Gatekeepers of Particle Flux Into the Mesopelagic Ocean in the Northeast Pacific Type $loc['typeJournal Article']
Year 2019 Publication Frontiers in Marine Science Abbreviated Journal Front. Mar. Sci.
Volume 6
Issue Pages
Keywords biological pump ; carbon export ; remineralization length scale ; mesozooplankton ecology ; pteropods ; marine biogeochemistry ; sinking particles ; marine snow
Abstract Zooplankton are important consumers of sinking particles in the ocean's twilight zone. However, the impact of different taxa depends on their feeding mode. In contrast to typical suspension-feeding zooplankton, flux-feeding taxa preferentially consume rapidly sinking particles that would otherwise penetrate into the deep ocean. To quantify the potential impact of two flux-feeding zooplankton taxa [Aulosphaeridae (Rhizaria), and Limacina helicina (euthecosome pteropod)] and the total suspension-feeding zooplankton community, we measured depth-stratified abundances of these organisms during six cruises in the California Current Ecosystem. Using allometric-scaling relationships, we computed the percentage of carbon flux intercepted by flux feeders and suspension feeders. These estimates were compared to direct measurements of carbon flux attenuation (CFA) made using drifting sediment traps and U-238-Th-234 disequilibrium. We found that CFA in the shallow twilight zone typically ranged from 500 to 1000 m mol organic C flux remineralized per 10-m vertical depth bin. This equated to approximately 6-10% of carbon flux remineralized/10 m. The two flux-feeding taxa considered in this study could account for a substantial proportion of this flux near the base of the euphotic zone. The mean flux attenuation attributable to Aulosphaeridae was 0.69%/10 m (median = 0.21%/10 m, interquartile range = 0.04-0.81%) at their depth of maximum abundance (similar to 100 m), which would equate to similar to 10% of total flux attenuation in this depth range. The maximum flux attenuation attributable to Aulosphaeridae reached 4.2%/10 m when these protists were most abundant. L. helicina, meanwhile, could intercept 0.45-1.6% of carbon flux/10 m, which was slightly greater (on average) than the Aulosphaeridae. In contrast, suspension-feeding zooplankton in the mesopelagic (including copepods, euphausiids, appendicularians, and ostracods) had combined clearance rates of 2-81 L m(-3) day(-1) (mean of 19.6 L m(-3) day(-1)). This implies a substantial impact on slowly sinking particles, but a negligible impact on the presumably rapidly sinking fecal pellets that comprised the majority of the material collected in sediment traps. Our results highlight the need for a greater research focus on the many taxa that potentially act as flux feeders in the oceanic twilight zone.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-7745
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1066
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Author Sun, J. ; Wu, Z.
Title Isolating spatiotemporally local mixed Rossby-gravity waves using multi-dimensional ensemble empirical mode decomposition Type $loc['typeJournal Article']
Year 2019 Publication Climate Dynamics Abbreviated Journal Clim Dyn
Volume Issue 3-4
Pages 1383-1405
Keywords
Abstract Tropical waves have relatively large amplitudes in and near convective systems, attenuating as they propagate away from the area where they are generated due to the dissipative nature of the atmosphere. Traditionally, nonlocal analysis methods, such as those based on the Fourier transform, are applied to identify tropical waves. However, these methods have the potential to lead to the misidentification of local wavenumbers and spatial locations of local wave activities. To address this problem, we propose a new method for analyzing tropical waves, with particular focus placed on equatorial mixed Rossby-gravity (MRG) waves. The new tropical wave analysis method is based on the multi-dimensional ensemble empirical mode decomposition and a novel spectral representation based on spatiotemporally local wavenumber, frequency, and amplitude of waves. We first apply this new method to synthetic data to demonstrate the advantages of the method in revealing characteristics of MRG waves. We further apply the method to reanalysis data (1) to identify and isolate the spatiotemporally heterogeneous MRG waves event by event, and (2) to quantify the spatial inhomogeneity of these waves in a wavenumber-frequency-energy diagram. In this way, we reveal the climatology of spatiotemporal inhomogeneity of MRG waves and summarize it in wavenumber-frequency domain: The Indian Ocean is dominated by MRG waves in the period range of 8–12 days; the western Pacific Ocean consists of almost equal energy distribution of MRG waves in the period ranges of 3–6 and 8–12 days, respectively; and the eastern tropical Pacific Ocean and the tropical Atlantic Ocean are dominated by MRG waves in the period range of 3–6 days. The zonal wavenumbers mostly fall within the band of 4–15, with Indian Ocean has larger portion of higher wavenumber (smaller wavelength components) MRG waves.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0930-7575
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1093
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Author Villas Bôas, A.B. ; Ardhuin, F. ; Ayet, A. ; Bourassa, M.A. ; Brandt, P. ; Chapron, B. ; Cornuelle, B.D. ; Farrar, J.T. ; Fewings, M.R. ; Fox-Kemper, B. ; Gille, S.T. ; Gommenginger, C. ; Heimbach, P. ; Hell, M.C. ; Li, Q. ; Mazloff, M.R. ; Merrifield, S.T. ; Mouche, A. ; Rio, M.H. ; Rodriguez, E. ; Shutler, J.D. ; Subramanian, A.C. ; Terrill, E.J. ; Tsamados, M. ; Ubelmann, C. ; van Sebille, E.
Title Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade Type $loc['typeJournal Article']
Year 2019 Publication Frontiers in Marine Science Abbreviated Journal Front. Mar. Sci.
Volume 6
Issue Pages
Keywords
Abstract Ocean surface winds, currents, and waves play a crucial role in exchanges of momentum, energy, heat, freshwater, gases, and other tracers between the ocean, atmosphere, and ice. Despite surface waves being strongly coupled to the upper ocean circulation and the overlying atmosphere, efforts to improve ocean, atmospheric, and wave observations and models have evolved somewhat independently. From an observational point of view, community efforts to bridge this gap have led to proposals for satellite Doppler oceanography mission concepts, which could provide unprecedented measurements of absolute surface velocity and directional wave spectrum at global scales. This paper reviews the present state of observations of surface winds, currents, and waves, and it outlines observational gaps that limit our current understanding of coupled processes that happen at the air-sea-ice interface. A significant challenge for the coming decade of wind, current, and wave observations will come in combining and interpreting measurements from (a) wave-buoys and high-frequency radars in coastal regions, (b) surface drifters and wave-enabled drifters in the open-ocean, marginal ice zones, and wave-current interaction �hot-spots,� and (c) simultaneous measurements of absolute surface currents, ocean surface wind vector, and directional wave spectrum from Doppler satellite sensors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-7745
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @
Serial 1064
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