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Author Zhao, X.; Zhou, C.; Xu, X.; Ye, R.; Tian, J.; Zhao, W.
Title Deep Circulation in the South China Sea Simulated in a Regional Model Type $loc['typeJournal Article']
Year 2019 Publication Ocean Sci. Discuss Abbreviated Journal Ocean Sci. Discuss
Volume Issue Pages
Keywords Sea Marine, Oceanography/CIMST, PacificOcean, continuous current-meter, deep circulation, deep western boundary
Abstract The South China Sea (SCS) is the largest marginal sea in the northwest Pacific Ocean. In this study, deep circulation in the SCS is investigated using results from eddy-resolving, regional simulations using the Hybrid Coordinate Ocean Model (HYCOM) verified by continuous current-meter observations. Analysis of these results provides a detailed spatial structure and temporal variability of the deep circulation in the SCS. The major features of the SCS deep circulation are a basin-scale cyclonic gyre and a concentrated deep western boundary current (DWBC). Transport of the DWBC is ∼ 2 Sv at 16.5° N with a width of ∼53 km. Flowing southwestward, the narrow DWBC becomes weaker with a wider range. The model results reveal the existence of 80- to 120-day oscillation in the deep northeastern circulation and the DWBC, which are also the areas with elevated eddy kinetic energy. This intraseasonal oscillation propagates northwestward with a velocity amplitude of ∼ 1.0 to 1.5 cm s-1. The distribution of mixing parameters in the deep SCS plays a role in both spatial structure and volume transport of the deep circulation. Compared with the northern shelf of the SCS with the Luzon Strait, deep circulation in the SCS is more sensitive to the large vertical mixing parameters of the Zhongsha Island Chain area.
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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 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @ Serial 1013
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Author Kim, D.; Lee, S.-K.; Lopez, H.; Foltz, G.R.; Misra, V.; Kumar, A.
Title On the Role of Pacific-Atlantic SST Contrast and Associated Caribbean Sea Convection in August-October U.S. Regional Rainfall Variability Type $loc['typeJournal Article']
Year 2020 Publication Geophysical Research Letters Abbreviated Journal Geophys. Res. Lett.
Volume 47 Issue 11 Pages
Keywords Pacific‐ Atlantic SST interaction; Atlantic Warm pool; Caribbean Sea; U.S. precipitation
Abstract This study investigates the large‐scale atmospheric processes that lead to U.S. precipitation variability in late summer to midfall (August–October; ASO) and shows that the well‐recognized relationship between North Atlantic Subtropical High and U.S. precipitation in peak summer (June–August) significantly weakens in ASO. The working hypothesis derived from our analysis is that in ASO convective activity in the Caribbean Sea, modulated by the tropical Pacific‐Atlantic sea surface temperature (SST) anomaly contrast, directly influences the North American Low‐Level Jet and thus U.S. precipitation east of the Rockies, through a Gill‐type response. This hypothesis derived from observations is strongly supported by a long‐term climate model simulation and by a linear baroclinic atmospheric model with prescribed diabatic forcings in the Caribbean Sea. This study integrates key findings from previous studies and advances a consistent physical rationale that links the Pacific‐Atlantic SST anomaly contrast, Caribbean Sea convective activity, and U.S. rainfall in ASO.
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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 0094-8276 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @ Serial 1110
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Author Kelly, T.B.; Goericke, R.; Kahru, M.; Song, H.; Stukel, M.R.
Title CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140 Issue Pages 14-25
Keywords CALIFORNIA CURRENT ECOSYSTEM; OCEAN CARBON-CYCLE; COASTAL WATERS; FRONTAL ZONE; TIME-SERIES; FLUX; SINKING; SEA; PACIFIC; ZOOPLANKTON
Abstract Estimating interannual variability in carbon export is a key goal of many marine biogeochemical studies. However, due to variations in export mechanisms between regions, generalized models used to estimate global patterns in export often fail when used for intra-regional analysis. We present here a region-specific model of export production for the California Current Ecosystem (CCE) parameterized using intensive Lagrangian process studies conducted during El Niño-Southern Oscillation (ENSO) warm and neutral phases by the CCE Long-Term Ecological Research (LTER) program. We find that, contrary to expectations from prominent global algorithms, export efficiency (e-ratio = export / primary productivity) is positively correlated with temperature and negatively correlated with net primary productivity (NPP). We attribute these results to the substantial horizontal advection found within the region, and verify this assumption by using a Lagrangian particle tracking model to estimate water mass age. We further suggest that sinking particles in the CCE are comprised of a recently-produced, rapidly-sinking component (likely mesozooplankton fecal pellets) and a longer-lived, slowly-sinking component that is likely advected long distances prior to export. We determine a new algorithm for estimating particle export in the CCE from NPP (Export = 0.08 · NPP + 72 mg C m-2 d-1). We apply this algorithm to a two-decade long time series of NPP in the CCE to estimate spatial and interannual variability across multiple ENSO phases. Reduced export during the warm anomaly of 2014-2015 and El Niño 2015-2016 resulted primarily from decreased export in the coastal upwelling region of the CCE; the oligotrophic offshore region exhibited comparatively low seasonal and interannual variability in flux. The model resolves intra-regional patterns of in situ export measurements, and provides a valuable contrast to global export models.
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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 0967-0637 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ rl18 @ Serial 984
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Author Kelly, T.B.; Goericke, R.; Kahru, M.; Song, H.; Stukel, M.R.
Title CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140 Issue Pages 14-25
Keywords california current ecosystem; coastal waters; flux; frontal zone; ocean carbon-cycle; oceanography; pacific; sea; sinking; time-series; Zooplankton
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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 0967-0637 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @ Serial 1022
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Author Morrow, R.M.; Ohman, M.D.; Goericke, R.; Kelly, T.B.; Stephens, B.M.; Stukel, M.R.
Title CCE V: Primary production, mesozooplankton grazing, and the biological pump in the California Current Ecosystem: Variability and response to El Niño Type $loc['typeJournal Article']
Year 2018 Publication Deep Sea Research Part I: Oceanographic Research Papers Abbreviated Journal Deep Sea Research Part I: Oceanographic Research Papers
Volume 140 Issue Pages 52-62
Keywords Carbon export; Fecal pellets; Sinking particles; Interannual variability; Net primary productivity; Eastern boundary upwelling system KeyWords Plus:ZOOPLANKTON FECAL PELLETS; NORTH PACIFIC-OCEAN; CURRENT SYSTEM; SOUTHERN CALIFORNIA; UNDERWATER GLIDERS; CARBON EXPORT; ZONE; CHLOROPHYLL; STABILITY; EQUATIONS
Abstract Predicting marine carbon sequestration in a changing climate requires mechanistic understanding of the processes controlling sinking particle flux under different climatic conditions. The recent occurrence of a warm anomaly (2014-2015) followed by an El Nino (2015-2016) in the southern sector of the California Current System presented an opportunity to analyze changes in the biological carbon pump in response to altered climate forcing. We compare primary production, mesozooplankton grazing, and carbon export from the euphotic zone during quasi-Lagrangian experiments conducted in contrasting conditions: two cruises during warm years – one during the warm anomaly in 2014 and one toward the end of El Nino 2016 – and three cruises during El Ninoneutral years. Results showed no substantial differences in the relationships between vertical carbon export and its presumed drivers (primary production, mesozooplankton grazing) between warm and neutral years. Mesozooplankton fecal pellet enumeration and phaeopigment measurements both showed that fecal pellets were the dominant contributor to export in productive upwelling regions. In more oligotrophic regions, fluxes were dominated by amorphous marine snow with negligible pigment content. We found no evidence for a significant shift in the relationship between mesozooplankton grazing rate and chlorophyll concentration. However, massspecific grazing rates were lower at low-to-moderate chlorophyll concentrations during warm years relative to neutral years. We also detected a significant difference in the relationship between phytoplankton primary production and photosynthetically active radiation between years: at similar irradiance and nutrient concentrations, productivity decreased during the warm events. Whether these changes resulted from species composition changes remains to be determined. Overall, our results suggest that the processes driving export remain similar during different climate conditions, but that species compositional changes or other structural changes require further attention.
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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 0967-0637 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ rl18 @ Serial 983
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Author Stukel, M.R.; Benitez-Nelson, C.R.; Decima, M.; Taylor, A.G.; Buchwald, C.; Landry, M.R.
Title The biological pump in the Costa Rica Dome: an open-ocean upwelling system with high new production and low export Type $loc['typeJournal Article']
Year 2016 Publication Journal of Plankton Research Abbreviated Journal J Plankton Res
Volume 38 Issue 2 Pages 348-365
Keywords Eastern Tropical Pacific; biogeochemistry; carbon flux; nutrients; plankton
Abstract The Costa Rica Dome is a picophytoplankton-dominated, open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone. To investigate the efficiency of the biological pump in this unique area, we used shallow (90-150 m) drifting sediment traps and 234Th:238U deficiency measurements to determine export fluxes of carbon, nitrogen and phosphorus in sinking particles. Simultaneous measurements of nitrate uptake and shallow water nitrification allowed us to assess the equilibrium balance of new and export production over a monthly timescale. While f-ratios (new:total production) were reasonably high (0.36 +/- 0.12, mean +/- standard deviation), export efficiencies were considerably lower. Sediment traps suggested e-ratios (export/14C-primary production) at 90-100 m ranging from 0.053 to 0.067. ThE-ratios (234Th disequilibrium-derived export) ranged from 0.038 to 0.088. C:N and N:P stoichiometries of sinking material were both greater than canonical (Redfield) ratios or measured C:N of suspended particulates, and they increased with depth, suggesting that both nitrogen and phosphorus were preferentially remineralized from sinking particles. Our results are consistent with an ecosystem in which mesozooplankton play a major role in energy transfer to higher trophic levels but are relatively inefficient in mediating vertical carbon flux to depth, leading to an imbalance between new production and sinking flux.
Address Scripps Institution of Oceanography , University of California at San Diego , La Jolla, CA 92037 , USA
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 0142-7873 ISBN Medium
Area Expedition Conference
Funding PMID:27275035; PMCID:PMC4889986 Approved $loc['no']
Call Number COAPS @ mfield @ Serial 90
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Author Ali, M.; Singh, N.; Kumar, M.; Zheng, Y.; Bourassa, M.; Kishtawal, C.; Rao, C.
Title Dominant Modes of Upper Ocean Heat Content in the North Indian Ocean Type $loc['typeJournal Article']
Year 2018 Publication Climate Abbreviated Journal Climate
Volume 6 Issue 3 Pages 71
Keywords ocean heat content; tropical cyclone heat potential; dominant modes; North Indian Ocean; SUMMER MONSOON; INTENSIFICATION; INTENSITY; PACIFIC
Abstract The thermal energy needed for the development of hurricanes and monsoons as well as any prolonged marine weather event comes from layers in the upper oceans, not just from the thin layer represented by sea surface temperature alone. Ocean layers have different modes of thermal energy variability because of the different time scales of ocean-atmosphere interaction. Although many previous studies have focused on the influence of upper ocean heat content (OHC) on tropical cyclones and monsoons, no study thus farparticularly in the North Indian Ocean (NIO)has specifically concluded the types of dominant modes in different layers of the ocean. In this study, we examined the dominant modes of variability of OHC of seven layers in the NIO during 1998-2014. We conclude that the thermal variability in the top 50 m of the ocean had statistically significant semiannual and annual modes of variability, while the deeper layers had the annual mode alone. Time series of OHC for the top four layers were analyzed separately for the NIO, Arabian Sea, and Bay of Bengal. For the surface to 50 m layer, the lowest and the highest values of OHC were present in January and May every year, respectively, which was mainly caused by the solar radiation cycle.
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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 2225-1154 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ rl18 @ Serial 986
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Author Moroni, D. F.
Title Global and Regional Diagnostic Comparison of Air-Sea Flux Parameterizations during Episodic Events Type $loc['typeManuscript']
Year 2008 Publication Abbreviated Journal
Volume Issue Pages
Keywords Parameterizations, Parameterization, Algorithm, Probability Density, Probability Distribution, Pdf, Drake Passage, Kuroshio, Gulf Stream Ect, Cold Tongue, Indian Ocean, Pacific Ocean, Southern Oceans, Atlantic Ocean, Tropics, Sea-State
Abstract Twenty turbulent flux parameterizations are compared globally and regionally with a focus on the differences associated with episodic events. The regional focus is primarily upon the Gulf Stream and Drake Passage, as these two regions contain vastly different physical characteristics related to storm and frontal passages, varieties of sea-states, and atmospheric stability conditions. These turbulent flux parameterizations are comprised of six stress-related parameterizations [i.e., Large and Pond (1981), Large et al. (1994), Smith (1988), HEXOS (Smith et al. 1992, 1996), Taylor and Yelland (2001), and Bourassa (2006)] which are paired with a choice of three atmospheric stability parameterizations ['Neutral' assumption, Businger-Dyer (Businger 1966, Dyer 1967, Businger et al. 1971, and Dyer 1974) relations, and Beljaars-Holtslag (1991) with Benoit (1977)]. Two remaining turbulent flux algorithms are COARE version 3 (Fairall et al. 2003) and Kara et al. (2005), where Kara et al. is a polynomial curve fit approximation to COARE; these have their own separate stability considerations. The following data sets were used as a common input for parameterization: Coordinated Ocean Reference Experiment version 1.0, Reynolds daily SST, and NOAA WaveWatch III. The overlapping time period for these data sets is an eight year period (1997 through 2004). Four turbulent flux diagnostics (latent heat flux, sensible heat flux, stress, curl of the stress) are computed using the above parameterizations and analyzed by way of probability distribution functions (PDFs) and RMS analyses. The differences in modeled flux consistency are shown to vary by region and season. Modeled flux consistency is determined both qualitatively (using PDF diagrams) and quantitatively (using RMS differences), where the best consistencies are found during near-neutral atmospheric stratification. Drake Passage shows the least sensitivity (in terms of the change in the tails of PDFs) to seasonal change. Specific flux diagnostics show varying degrees of consistency between stability parameterizations. For example, the Gulf Stream's latent heat flux estimates are the most inconsistent (compared to any other flux diagnostic) during episodic and non-neutral conditions. In all stability conditions, stress and the curl of stress are the most consistent modeled flux diagnostics. Sea-state is also a very important source of modeled flux inconsistencies during episodic events for both regions.
Address Department of Meteorology
Corporate Author Thesis $loc['Ph.D. thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 609
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Author Samuelsen, A
Title Modeling the Effect of Eddies and Advection on the Lower Trophic Ecosystem in the Northeast Tropical Pacific Type $loc['typeManuscript']
Year 2005 Publication Abbreviated Journal
Volume Issue Pages
Keywords Physical-Biological Interactions, Marine Ecosystem Modeling, Pacific Ocean, Gulf Of Tehuantepec, Costa Rica Dome, Cross-Shelf Transport, Eddies
Abstract A medium complexity, nitrogen-based ecosystem model is developed in order to simulate the ecosystem in the northeast tropical Pacific. Several physical processes have major impact on the ecosystem in this region, most importantly intense wind jets along the coast and upwelling at the Costa Rica Dome (CRD). The ecosystem model is run “offline”, using a realistic physical ocean model hindcast as input. The physical model is a subdomain of the global Navy Coastal Ocean Model, which is a hybrid sigma-z level model. The model assimilates Modular Ocean Data Assimilation System temperature and salinity profiles derived from altimetry and sea surface temperature data. The model is forced by daily heat and momentum fluxes, and therefore captures short-term wind events such as the Tehuantepec jet. Because the model has high horizontal resolution (~1/8 degree) and assimilates sea surface height data, it has a realistic representation of eddies and mesoscale variability. The ecosystem model includes two nutrients (nitrate and ammonium), two size-classes of phytoplankton, two size-classes of zooplankton, and detritus. The model is run for 4 years from 1999 to 2002, with analyses focused on 2000-2002. The model is validated using SeaWiFS data and ship-based observations from the STAR-cruises (Stenella Abundance Research Project) of 1999 and 2000. The northernmost and most intense of the wind jets along Central America is the Tehuantepec jet. The Tehuantepec jet is responsible for upwelling large amounts of nutrient rich water south of the Gulf of Tehuantepec. The jet also occasionally produce large anti-cyclonic eddies that transport organic matter away from the coast. Because organic matter that is transported into the open ocean will eventually sink to the deep ocean, this has implications for the carbon export in this region. The model results are used to calculate cross-shelf fluxes in this region in order to estimate how much organic material is transported across the shelf break. Results show that at the Gulf of Tehuantepec there is high offshore export of organic material, particularly during eddy generation events, but also in fall. The highest export is on the order of 10 Mg C per meter of coastline per day and happens during eddy events. During these events there is a comparable onshore flux to the south of the gulf. Typically there is onshore flux to the south of the gulf during the summer. The model estimated transport away from the coast at the Gulf of Tehuantepec is 167 Tg C/year, and the onshore transport to the south of the gulf is 704 Tg C/year. The second subject of interest is the CRD. In this region, upwelling at the surface is caused by Ekman upwelling during the summer, although the dome is thought to be present at depth throughout the year. The doming of the isotherms below the thermocline is a result of vortex stretching and is decoupled from the wind-driven processes at the surface. A mass-balance budget is calculated at the CRD, and the horizontal and vertical fluxes are related to the abundance of plankton at the dome. There is upwelling (7.2X10-2 Sv ) at the dome throughout the year, but around the location of the dome (90° W), the upwelling is largest in the winter. Further west, input of nutrients from below is larger in the fall and summer. The results suggest that about 80% of the nitrate that is supplied to the dome during summer is actually brought up to the west of the dome and transported eastward by the North Equatorial Counter Current.
Address Department of Oceanography
Corporate Author Thesis $loc['Ph.D. thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 591
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Author Tseng, Y.-heng; Lin, H.; Chen, H.-ching; Thompson, K.; Bentsen, M.; Böning, C.W.; Bozec, A.; Cassou, C.; Chassignet, E.; Chow, C.H.; Danabasoglu, G.; Danilov, S.; Farneti, R.; Fogli, P.G.; Fujii, Y.; Griffies, S.M.; Ilicak, M.; Jung, T.; Masina, S.; Navarra, A.; Patara, L.; Samuels, B.L.; Scheinert, M.; Sidorenko, D.; Sui, C.-H.; Tsujino, H.; Valcke, S.; Voldoire, A.; Wang, Q.; Yeager, S.G.
Title North and equatorial Pacific Ocean circulation in the CORE-II hindcast simulations Type $loc['typeJournal Article']
Year 2016 Publication Ocean Modelling Abbreviated Journal Ocean Modelling
Volume 104 Issue Pages 143-170
Keywords CORE global ocean-ice simulations; Kuroshio; Mode water; Subtropical cell; North Pacific simulations
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 @ mfield @ Serial 55
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