| The marine biogeochemical cycle is reflected in the spatial and temporal variability of particulate organic carbon (POC). Because POC is related to biological processes (e.g. photosynthesis, grazing) quantification of its distribution may indicate how the marine biogeochemical cycle responds to changes in physical environment. Past efforts to quantify POC by bottle sampling or in-situ filtration, however, have been hampered by difficulties in obtaining representative samples (bias and sparseness). The use of transmissometer data (beam attenuation coefficient) as a proxy for POC addresses this problem.; Here, beam attenuation coefficient data from the subarctic Pacific were used to identify processes that control the POC distribution in this high nutrients low chlorophyll (HNLC) region. The combined influence of several factors including mixed layer depth (including mixing history), availability of light for marine photosynthetic organisms and grazing on POC distributions was examined.; Values of POC were calculated from the beam attenuation coefficient data obtained from two surveys in the subarctic Pacific: the 1995 Highseas survey (53 stations, March–April) and the 1993 INPOC survey (69 stations, April–May). (Abstract shortened by UMI.)... |
