|Burdige, David J||Old Dominion University (ODU)||Principal Investigator|
|Long, Matthew||Woods Hole Oceanographic Institution (WHOI)||Co-Principal Investigator|
|Zimmerman, Richard C.||Old Dominion University (ODU)||Co-Principal Investigator|
|Copley, Nancy||Woods Hole Oceanographic Institution (WHOI BCO-DMO)||BCO-DMO Data Manager|
This dataset includes oxygen profiles from sediment core samples collected in the northern Gulf of Mexico in May 2017.
Sediment cores were collected by divers, sealed in the field with rubber stoppers and returned to the lab for processing. Pore waters were collected by inserting rhizon samplers (Seeberg-Elverfeldt et al., 2005) through pre-drilled holes in the core tubes. Samples were collected in gas-tight glass syringes and filtered through 0.45 µm nylon filters into storage vials. Oxygen profiles in the cores were collected with polarographic microelectrodes (Luther et al., 2008) using a DLK 70 WebPstat electrochemical analyzer (AIS, Inc.) and a computer-controlled micro-profiler.
Note: 'sd' in this dataset means that the electrode signal deterioriated, likely due to sulfide interference.
BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- added columns for site, lat, and lon
- reformatted collection date and time from m/d/yyyy H:MM to YYYY-MM-DDTHH:MM:SS (ISO 8601:2004E)-
- transformed table to flat format by reproducing rows core, profile, datetime_collected and scanned to columns for each depth/O2 record
- re-ordered records by site name
- changed Spidercrab Bay core id's from SC* to SP*
|site||sample collection site identifier||unitless|
|lat||latitude; north is positive||decimal degrees|
|lon||longitude; east is positive||decimal degrees|
|profile||profile replicate identifier||unitless|
|ISO_DateTime_Local_collected||local date and time sample was collected; formatted as YYYY-MM-DDTHH:MM:SS (ISO 8601:2004€ )||unitless|
|ISO_DateTime_Local_scan||local date and time when oxygen profiling began; formatted as YYYY-MM-DDTHH:MM:SS (ISO 8601:2004€ )||unitless|
|depth_cm||depth of oxygen reading within the core sample; bottom water refers to scan collected approximately 0.5 cm above the sediment surface||centimeters|
|O2_uM||dissolved oxygen concentration||microMoles|
|Dataset-specific Instrument Name|| |
DLK 70 WebPstat electrochemical analyzer (AIS, Inc.)
|Generic Instrument Name|| |
Oxygen Microelectrode Sensor
|Dataset-specific Description|| |
Oxygen was measured with polarographic microelectrodes using a DLK 70 WebPstat electrochemical analyzer (AIS, Inc.) and a computer-controlled micro-profiler.
|Generic Instrument Description|| |
A miniaturized Clark-type dissolved oxygen instrument, including glass micro-sensors with minute tips (diameters ranging from 1 to 800 um). A gold or platinum sensing cathode is polarized against an internal reference and, driven by external partial pressure, oxygen from the environment penetrates through the sensor tip membrane and is reduced at the sensing cathode surface. A picoammeter converts the resulting reduction current to a signal. The size of the signal generated by the electrode is proportional to the flux of oxygen molecules to the cathode.The sensor also includes a polarized guard cathode, which scavenges oxygen in the electrolyte, thus minimizing zero-current and pre-polarization time.With the addition of a meter and a sample chamber, the respiration of a small specimen can be measured. Example: Strathkelvin Inst. http://www.strathkelvin.com
This research will develop a quantitative understanding of the factors controlling carbon cycling in seagrass meadows that will improve our ability to quantify their potential as blue carbon sinks and predict their future response to climate change, including sea level rise, ocean warming and ocean acidification. This project will advance a new generation of bio-optical-geochemical models and tools (ECHOES) that have the potential to be transform our ability to measure and predict carbon dynamics in shallow water systems.
This study will utilize cutting-edge methods for evaluating oxygen and carbon exchange (Eulerian and eddy covariance techniques) combined with biomass, sedimentary, and water column measurements to develop and test numerical models that can be scaled up to quantify the dynamics of carbon cycling and sequestration in seagrass meadows in temperate and tropical environments of the West Atlantic continental margin that encompass both siliciclastic and carbonate sediments. The comparative analysis across latitudinal and geochemical gradients will address the relative contributions of different species and geochemical processes to better constrain the role of seagrass carbon sequestration to global biogeochemical cycles. Specifically the research will quantify: (i) the relationship between C stocks and standing biomass for different species with different life histories and structural complexity, (ii) the influence of above- and below-ground metabolism on carbon exchange, and (iii) the influence of sediment type (siliciclastic vs. carbonate) on Blue Carbon storage. Seagrass biomass, growth rates, carbon content and isotope composition (above- and below-ground), organic carbon deposition and export will be measured. Sedimentation rates and isotopic composition of PIC, POC, and iron sulfide precipitates, as well as porewater concentrations of dissolved sulfide, CO2, alkalinity and salinity will be determined in order to develop a bio-optical-geochemical model that will predict the impact of seagrass metabolism on sediment geochemical processes that control carbon cycling in shallow waters. Model predictions will be validated against direct measurements of DIC and O2 exchange in seagrass meadows, enabling us to scale-up the density-dependent processes to predict the impacts of seagrass distribution and density on carbon cycling and sequestration across the submarine landscape.
Status, as of 09 June 2016: This project has been recommended for funding by NSF's Division of Ocean Sciences.
|NSF Division of Ocean Sciences (NSF OCE)|
|NSF Division of Ocean Sciences (NSF OCE)|
This document is created by info v 4.1f 5 Oct 2018 from the content of the BCO-DMO metadata database. 2021-01-27 08:35:12