25 research outputs found
Evaluation of Dredged Material Proposed for Ocean Disposal from Port Chester, New York
Port Chester was one of seven waterways that the US Army Corps of Engineers-New York District requested the Battelle Marine Sciences Laboratory to sample and evaluate for dredging and disposal in March 1994. Tests and analyses were conducted on Port Chester sediment core samples. Because the Port Chester area is located on the border between New York and southeast Connecticut, its dredged material may also be considered for disposal at the Central Long Island Sound Disposal Site. The sediment evaluation consisted of bulk sediment chemical analyses, chemical analyses of site water and dredged material elutriate preparations, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Port Chester were analyzed for grain size, moisture content, and total organic carbon. In addition, sediment was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl congers, polynuclear aromatic hydrocarbons and 1,4-dichlorobenzene
Recommended from our members
Evaluation of dredged material proposed for ocean disposal from Hudson River, New York
The Hudson River (Federal Project No. 41) was one of seven waterways that the U.S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. Sediment samples were collected from the Hudson River. Tests and analyses were conducted on Hudson River sediment core samples. The evaluation of proposed dredged material from the Hudson River included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Hudson River were analyzed for grain size, moisture content, and total organic carbon (TOC). A composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAH), and 1,4-dichlorobenzene. Site water and elutriate water, prepared from the suspended-particulate phase (SPP) of Hudson River sediment, were analyzed for metals, pesticides, and PCBS. Water-column or SPP toxicity tests were performed with three species. Benthic acute toxicity tests were performed. Bioaccumulation tests were also conducted
Recommended from our members
Evaluation of dredged material proposed for ocean disposal from South Brother Island Channel, New York
South Brother Island Channel was one of seven waterways that the US Army Crops of Engineers-New York District requested the Battelle/Marine Sciences Laboratory to sample and evaluate for dredging and disposal. Tests and analyses were conducted on South Brother Island Channel sediment core samples and evaluations were performed. The evaluation of proposed dredged material from South Brother Island Channel included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water-column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples collected from Souther Brother Island Channel were analyzed for grain size, moisture content, and total organic carbon. a composite sediment sample, representing the entire area proposed for dredging, was analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl congers, polynuclear aromatic hydrocarbons, and 1,4- dichlorobenzene. Site water and elutriate water, prepared from the suspended-particle phase of South Brother Island Channel sediment, were analyzed for metals, pesticides, and PCBs
Recommended from our members
Evaluation of dredged material proposed for ocean disposal from Buttermilk Channel, New York
Buttermilk Channel was one of seven waterways that was sampled and evaluated for dredging and sediment disposal. Sediment samples were collected and analyses were conducted on sediment core samples. The evaluation of proposed dredged material from the channel included bulk sediment chemical analyses, chemical analyses of site water and elutriate, water column and benthic acute toxicity tests, and bioaccumulation studies. Individual sediment core samples were analyzed for grain size, moisture content, and total organic carbon. A composite sediment samples, representing the entire area proposed for dredging, was analyzed for bulk density, polynuclear aromatic hydrocarbons, and 1,4-dichlorobenzene. Site water and elutriate were analyzed for metals, pesticides, and PCBs
Recommended from our members
Evaluation of dredged material proposed for ocean disposal from Eastchester Project Area, New York
The objective of the Eastchester project (Federal Project [FP] No. 6) was to evaluate proposed dredged material from the Eastchester project area in the Hutchinson River to determine its suitability for unconfined ocean disposal at the Mud Dump Site. Eastchester was one of seven waterways that the U. S. Army Corps of Engineers-New York District (USACE-NYD) requested the Battelle/Marine Sciences Laboratory (MSL) to sample and evaluate for dredging and disposal in March 1994. The evaluation of proposed dredged material from the Eastchester project area consisted of bulk sediment chemical analyses, chemical analyses of dredging site water and elutriate, water- column and benthic acute toxicity tests, and bioaccumulation studies. Eighteen individual sediment core samples collected from the Eastchester project area were analyzed for grain size, moisture content, and total organic carbon (TOC). Two composite sediment samples, representing the upstream and lower reaches of the area proposed for dredging, were analyzed for bulk density, specific gravity, metals, chlorinated pesticides, polychlorinated biphenyl (PCB) congeners, polynuclear aromatic hydrocarbons (PAHs), and 1,4- dichlorobenzene. Dredging site water and elutriate water, which is prepared from the suspended-particulate phase (SPP) of the two Eastchester sediment composites, were analyzed for metals, pesticides, and PCBS. An additional 1 1 composite samples were created for the USACE-New England Division (USACE-NED) using the same 18 Eastchester core samples but combined into different composites. These composites were analyzed for metals, chlorinated pesticides, PCB congeners, PAHS, and 1,4-dichlorobenzene. Water-column or SPP toxicity tests were performed along with bioaccumulation tests
Vortex merger near a topographic slope in a homogeneous rotating fluid
This work is a contribution to the PHYSINDIEN research program. It was supported by CNRS-RFBR contract PRC 1069/16-55-150001.The effect of a bottom slope on the merger of two identical Rankine vortices is investigated in a two dimensional, quasi-geostrophic, incompressible fluid. When two cyclones initially lie parallel to the slope, and more than two vortex diameters away from the slope, the critical merger distance is unchanged. When the cyclones are closer to the slope, they can merge at larger distances, but they lose more mass into filaments, thus weakening the efficiency of merger. Several effects account for this: the topographic Rossby wave advects the cyclones, reduces their mutual distance and deforms them. This along shelf wave breaks into filaments and into secondary vortices which shear out the initial cyclones. The global motion of fluid towards the shallow domain and the erosion of the two cyclones are confirmed by the evolution of particles seeded both in the cyclone sand near the topographic slope. The addition of tracer to the flow indicates that diffusion is ballistic at early times. For two anticyclones, merger is also facilitated because one vortex is ejected offshore towards the other, via coupling with a topographic cyclone. Again two anticyclones can merge at large distance but they are eroded in the process. Finally, for taller topographies, the critical merger distance is again increased and the topographic influence can scatter or completely erode one of the two initial cyclones. Conclusions are drawn on possible improvements of the model configuration for an application to the ocean.PostprintPeer reviewe
Long-term climate change commitment and reversibility: an EMIC intercomparison
This paper summarizes the results of an intercomparison project with Earth System Models of Intermediate Complexity (EMICs) undertaken in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). The focus is on long-term climate projections designed to: (i) quantify the climate change commitment of different radiative forcing trajectories, and (ii) explore the extent to which climate change is reversible on human timescales. All commitment simulations follow the four Representative Concentration Pathways (RCPs) and their extensions to 2300. Most EMICs simulate substantial surface air temperature and thermosteric sea level rise commitment following stabilization of the atmospheric composition at year-2300 levels. The meridional overturning circulation (MOC) is weakened temporarily and recovers to near pre-industrial values in most models for RCPs 2.6–6.0. The MOC weakening is more persistent for RCP 8.5. Elimination of anthropogenic CO2 emissions after 2300 results in slowly decreasing atmospheric CO2 concentrations. At year 3000 atmospheric CO2 is still at more than half its year-2300 level in all EMICs for RCPs 4.5–8.5. Surface air temperature remains constant or decreases slightly and thermosteric sea level rise continues for centuries after elimination of CO2 emissions in all EMICs. Restoration of atmospheric CO2 from RCP to pre-industrial levels over 100–1000 years requires large artificial removal of CO2 from the atmosphere and does not result in the simultaneous return to pre-industrial climate conditions, as surface air temperature and sea level response exhibit a substantial time lag relative to atmospheric CO2