Performance of large volume water transfer systems during in-situ water sampling

During the Joint North Pacific Research Center (J-PAC) 2002 cruise on R/V Mirai, eight Large Volume Water Transfer Systems (WTS-LV) equipped with 4 l/min. pump heads were simultaneously deployed on 14 casts. The WTS-LV pumps were positioned along the vessel´s hydrowire so that they spanned a significant portion of the water column on each cast. A total of 112 samples were attempted with 108 viable samples acquired. A combined volume in excess of 56,000 liters was filtered during the casts. Each system collected engineering data, internally logging flow rate, cumulative volume, and battery voltage every 10 minutes during sample acquisition. This well correlated data set was analyzed to improve our understanding of WTS-LV system performance in real deployment situations. The field results demonstrate the ability of these systems to sample large volumes of water at various depths and with different types of filters. In addition to the analysis of these systems, this paper discusses ongoing WTS-LV development and planned improvements to the design.