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Penetration Of Anthropogenic Carbon Into Organic Particles Of The Deep Ocean, Erm Druffel, Je Bauer, S Griffin, J Hwang
Penetration Of Anthropogenic Carbon Into Organic Particles Of The Deep Ocean, Erm Druffel, Je Bauer, S Griffin, J Hwang
VIMS Articles
] In the late 1980s, bomb C-14 was present in suspended particulate organic carbon (POC) from the North Central Pacific (NCP) and Sargasso Sea ( SS) throughout most of the water column, demonstrating that deep POC had exchanged with atmospheric CO2 in the past 30 years. Upon reoccupation of these sites in 1999 and 2000, respectively, we observed that the delta(13)C values of suspended POC were lower than those measured a decade earlier. This demonstrates that anthropogenic CO2 from fossil fuel and biomass burning has penetrated a major organic matter pool in the deep ocean. Delta(14)C measured in the suspended …
Observations On The Distribution Of Meroplankton During An Upwelling Event, Al Shanks, J Largier, J Brubaker
Observations On The Distribution Of Meroplankton During An Upwelling Event, Al Shanks, J Largier, J Brubaker
VIMS Articles
The distribution of the larvae of benthic invertebrates was investigated relative to hydrographic structures as a test of the hypothesi's that larvae behave as if they are passive particles. Observations of larval and oceanographic distributions were made off Duck, North Carolina, USA in August 1994. Conditions were characterized by wind-driven coastal upwelling;flow was generally offshore near the surface and onshore below the pycnocline. Within 5 km of the shore the pycnocline was bent upward by the upwelling and it intersected the surface along most of the transects. In zooplankton samples, 20 taxa of larvae were counted (10 bivalve veligers, nine …
Dissolved Organic Nitrogen: A Dynamic Participant In Aquatic Ecosystems, T Berman, Da Bronk
Dissolved Organic Nitrogen: A Dynamic Participant In Aquatic Ecosystems, T Berman, Da Bronk
VIMS Articles
In both marine and freshwaters, the concentration of dissolved organic nitrogen (DON) frequently exceeds that of dissolved inorganic nitrogen (DIN), including ammonium, nitrate, and nitrite. Recent evidence indicates that many organic N compounds are released into the DON pool and taken up from this pool by planktonic microbiota on timescales of hours to days. This observation suggests that many components of the DON pool can play an active role in supplying N nutrition directly or indirectly to phytoplankton and bacteria and, in so doing, may affect the species composition of the ambient microbial assemblage. Here we present an overview of …
Phytoplankton Assemblage Structure And Primary Productivity Along 170 Degrees W In The South Pacific Ocean, Gr Ditullio, Me Greesey, Dr Jones, Kl Daly, L Campbell, Walker O. Smith Jr.
Phytoplankton Assemblage Structure And Primary Productivity Along 170 Degrees W In The South Pacific Ocean, Gr Ditullio, Me Greesey, Dr Jones, Kl Daly, L Campbell, Walker O. Smith Jr.
VIMS Articles
Phytoplankton pigments were measured using HPLC during non-ENSO conditions in mid-summer along a South Pacific transect from 67degreesS to the equator along 170degreesW. Highest concentrations of chlorophyll a (chl a) occurred in the Polar and the Subtropical Fronts (PF and STF, respectively) with concentrations exceeding 500 ng l(-1). In the STF, there was a distinct subsurface chl a maximum (SCM) at 40 m, which gradually deepened northward to 120 m in the Subtropical Convergence Zone. Northwards, the SCM shoaled to about 30 m in the Equatorial Zone (EZ). Relatively high concentrations of fucoxanthin and 19'-butanoyloxyfucoxanthin occurred in the nutrient-rich waters …
Numerical Modeling Of Gravity-Driven Sediment Transport And Deposition On An Energetic Continental Shelf: Eel River, Northern California, M. Scully, Carl T. Friedrichs, L. D. Wright
Numerical Modeling Of Gravity-Driven Sediment Transport And Deposition On An Energetic Continental Shelf: Eel River, Northern California, M. Scully, Carl T. Friedrichs, L. D. Wright
VIMS Articles
A two-dimensional numerical model was applied to predict large-scale deposition by wave-supported sediment gravity flows on the Eel River continental shelf for four consecutive flood seasons using measured bathymetry, waves and river forcing. The model assumes that sediment-induced stratification maintains the near-bed Richardson number at its critical value, which determines the sediment carrying capacity of the wave boundary layer. Deposition is predicted when the gravity-driven flux of sediment exceeds the carrying capacity. The model predicted 26% of fine sediment discharged by the Eel River to be deposited on the midshelf with a magnitude and distribution largely consistent with field observations. …
Spectral Estimates Of Bed Shear Stress Using Suspended-Sediment Concentrations In A Wave-Current Boundary Layer, Guan-Hong Lee, W. Brian Dade, Carl T. Friedrichs, Chris E. Vincent
Spectral Estimates Of Bed Shear Stress Using Suspended-Sediment Concentrations In A Wave-Current Boundary Layer, Guan-Hong Lee, W. Brian Dade, Carl T. Friedrichs, Chris E. Vincent
VIMS Articles
High-resolution time series of suspended-sediment profiles have been obtained using an acoustic backscatter system at an inner shelf site (North Carolina) where flows are dominated by wind-driven currents and waves. We analyzed the spatial and temporal structure of near-bed turbulence in particle-transporting flows and scalar-like fluctuations of suspended-sediment concentrations. An important element of our analysis is a new inertial dissipation method for passive tracers to estimate the shear stress acting on the seabed, using the spectral properties of suspended sediment concentrations observed by acoustic backscatter sensors. In flows that provide adequate separation of the scales of turbulence production and dissipation, …