Multiple Unit Large Volume Filtration System

deployment during the Canadian Joint Global Ocean Flux Study (C-JGOFS)

The image shows one of the Large Volume pumps being deployed from the afterdeck of the J.P. Tully during the Febuary 1996 C-JGOFS expedition along Line P to Station Papa The people from left to right are Steve (deck hand), Todd (MULVFS person), Hugh (UBC tech), Jim (MULVFS owner) and John (bosun).

Since the 1996-1997 campaign, MULVFS has been to sea in the California Current (2001) Southern Ocean (2002) during the SOFeX (Southern Ocean Iron Experiment), Station ALOHA near Hawaii (2004) and Station K2 in the Oyashio current near Japan (2005).

The MULVFS has 12 pump/filtration units, each capable of filtering up to 16,000 L of seawater through a filter series consisting of 53 um polyester mesh and a pair of 1 um quartz fiber filters. Each of the pumps also processes 2500 L through adsorber cartridges designed to trap dissolved natural uranium series radionuclides (particularly Th-234/U-238) present in seawater. Another flow channel allows processing of 100-200 L through specialized adsorber/filter combinations.

The 12 light-weight/low-drag pumps are operated simultaneously in profile from the surface to 1000 m depths using ship-generated 440VAC 3-phase power. This is accomplished via an uniquely engineered 1000 m long electromecanical cable and cable handling system. Depth and flowrate information is transmitted in real time from several pump units during operation.

Typical station time is 7-8 hours including deployment and recovery. Operations require a minimum of 2 people at sea. The system is designed to be tolerant of winter time conditions.


MULVFS Pumps and Cable Handling System MULVFS System Detail MULVFS Samples are Shared LVFS and MULVFS station locations

FTP access to 1996 and 1997 results from MULVFS along "Line P".

"CJGOFS Line P data archives".

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