Project CATSTIX : camera, transmissometer and sediment trap integration experiment /
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| Other Authors: | , , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Project CATSTIX (CAmera, Transmissometer, Sediment Trap Intercomparison eXperiment) was designed to compare three in situ particle measurement methodologies to see if the limitations of each method could be overcome by integrating the data from each into a combined methodology that can be used at the time and space scales of biological and physical modeling. Transmissiometers measure the concentration of small particles in the range of a few microns and less. Small particles dominate the particle mass concentration in the oceanic water column, but because they have very low settling velocities do not contribute appreciably to the particle mass flux. Sediment traps measure the particle mass flux but necessarily integrate the sample over time periods that may be longer than the natural processes, such as blooms, that control the particle mass flux. Marine aggregates with diameters greater than 0.5 mm are thought to be the largest contributor to the particle mass flux due to their size, settling velocity and abundance. However, the size distribution and settling velocity of aggregates cannot be measured from the material captured in sediment traps. Large particle cameras have been used to measure the abundance and size distribution of aggregates, but until now data from large particle cameras have not been successfully compared with measured fluxes from sediment traps. This study was conducted in the northwest Gulf of Mexico over the continental slope during 1987 and 1988. During the time of this study the distribution of small particles in the northwest Gulf of Mexico was influenced by biological production and the presence of mesoscale warm and cold core circulation features. Additionally, biological processes apparently created diel variations in beam attenuation that were observed in the surface layer and in intermediate nepheloid layer. This is the first time diel variations have been observed at depths greater than 100 m. Mesoscale circulation was found to also contribute to the cross-slope advection of aggregates. The large particle camera adequately measured particle size distributions in the aggregate size range (d > 0.5mm), and aggregate mass fluxes were calculated and ranged from 10 to 80 μg cm^-2d^-1. The calculated aggregate fluxes were found to correlate with fluxes measured in sediment traps which ranged from 15 to 35 μg cm^-2d^-1. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Oceanography." |
| Physical Description: | xii, 96 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |