Acoustic Doppler Current Profilers (ADCP) will be used in high shear zones, with 

 conventional taut wire moorings located in less complex regions and to compliment the 

 ADCPs. Salinity, temperature, pressure, oxygen concentration, fluorescence, and particle 

 concentration measurements will be made throughout the mooring array using in-situ CTD and 

 oxygen sensors, fluorometers, transmissometers and turbidity sensors. Transmission profiles 

 will provide temporal and spatial data sets on fine particle resuspension and advection events 

 associated with storms. 



An intensive investigation of particulate dynamics and transport within the BBL will be 

 carried out as part of the OMP's moored instrument study. This effort will rely heavily on the 

 use of the BASS tripod system. The standard form of this system includes a string of 8 

 thermistors, a CTD and a stack of 6 acoustic travel time current meters extending from 20 to 

 450 cm above the sea floor. To resolve suspended sediment concentrations, each BASS 

 system used in the OMP will be equipped with Optical BackScatterance (OBS) sensors and 

 transmissometers. The small size and streamlined shape of the OBS sensors will allow them 

 to be located near each current meter without appreciable distortion of the flow. The 

 combination of velocity from the current meters and sediment concentration estimates from the 

 OBS will permit estimation of sediment flux through the bottom boundary layer, an operation 

 not previously possible. 



With the goal of estimating near-bottom POC fluxes, a subset of the BASS systems 

 deployed in the OMP will be outfitted with fiber optic fluorometer arrays. Calibration of OBS 

 and fluorometric measurements to POC will be made using simultaneous measures of organic 

 matter from time-series water samplers. BASS units will be placed on both of the primary 

 mooring lines of the OMP, with the heaviest concentration over the middle shelf to the shelf 

 edge. Additional near-bottom velocity and optical particle sensors will be placed at several 

 mooring locations not equipped with BASS tripods. The analysis of the data from these and 

 the BASS instruments will initially focus on sediment and fluid dynamics over the Cape 

 Hatteras region. Attention will be given to determine the extent that the various candidate 

 resuspension and transport processes contribute to the export of particles from the shelf. The 

 detail of the BASS measurements will allow us to study and better parameterize the operation 

 of these mechanisms. Using the near-bottom fluorometer measurements together with 

 relationships of suspended sediment to POC and DOC concentrations, determined in other 

 aspects of the OMP, we will also examine the flux of carbon in the bottom boundary layer and 

 attempt to assess its importance on the overall shelf carbon budget. 



Satellite and aircraft sea surface temperature (AVHRR), ocean color (SeaWifs), ocean 

 topography (Topex), synthetic and real aperture radar (SAR, RAR), surface sea state and wind 

 (SSMI) will be obtained either in real time (AVHRR, SeaWifs) or directiy from collaborating 

 government agencies (NASA-JPL, ONR-NRL). The real-time satellite (AVHRR and SeaWifs) 

 data will be used to guide shipboard surveys. Other satellite data will be utilized to identify 

 shelf, slope and Gulf Stream-related features outside and inside the array and to determine the 

 impact of these features on the enclosed region through correlation with direct 

 contemporaneous measurements of velocity and particle concentration and flux. 



The moorings will also be instrumented with pC02 sensors located at various depths in 

 the water column. Continuous time-series measurements of pC02 made in combination with 

 other physical, bio-optical, and oxygen measurements will provide a means for determining 

 what factors control the flux of CO2 across the air-sea interface. After deployment, the 



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