Resurser

Instrumental capacity in, or supported by the research group for Marine Systems Analysis.

Ship based instrumentation

Onboard R/V Skagerak (managed by the Sven Lovén Centre for Marine Sciences) we have two hull-mounted Acoustic Doppler Current Profilers (ADCP). The ADCPs measure profiles of water velocity down to 300-400 m depths while underway. This gives very good spatial coverage in a relatively short time.

Skagerak is also equipped with a towed undulating vehicle: a Scanfish mkII. This instrument may carry a number of sensors measuring parameters like conductivity (C – i.e. salinity), temperature (T), pressure (P), fluorescence (F), photosynthetically active radiation (PAR) and other parameters. This platform increase the possibilities to obtain relatively small scaled features and patches in the hydrography.

For station work and water samples a Seabird 911 Plus is used. This CTD is at time being the most accurate available.

Moored instrumentation

To obtain time series of oceanographic parameters we deploy instruments along moorings. The spatial resolution is then limited by the number of instruments (loggers) or sensor carrying platforms deployed. At present the capacity comprise for velocity measurements; 4 300 kHz Workhorse ADCPs (RDI) with a nominal range of 100 m. These are for larger scales (> 100 m horisontally, > 1 m vertically). For finescale (~ centimeters) measurements we have a single point Acoustic Doppler Velocimeter, ADV (Nortek, Vektor). For coarser scales (~ decimeters) we have an ACM (FSI) and a 1200 kHz ADC2P (RDI).

The density stratification is obtained using highly accurate CT-loggers (25 Microcats, Seabird) of which some have optional pressure sensors. Additional resolution of the temperature field is obtained using simple T-loggers (15, Richard Brancker).

New technology moored instrumentation

At present (May 2001) we are testing an autonomous, multi-cycling, data collecting platform called SeaTramp (Ocean Origo). The platform can carry a number of sensors. It is at present scanning for C, T, D, F, PAR, Light transmission and NO4. The last sensor (Nitrate) demand substantial service and care-taking and limit the platform to operate in brake mode i.e. stop at prescribed depths. Purchase of two such platforms are initiated and financed. The instrument make possible hitherto unapproached time series of continuos profiles but require improved mooring equipment and regular service and knowledge.

Workboat

A 40 feet workboat has been optimized and built in aluminum alloy with a first duty to manage and service the moorings described above. It is put into operation in May 2001. It will eventually have capacity for small surveys. It can be equipped with an ADCP (or other) in a well and a real-time logging CTD. It has good navigational and echo-sounding resources.

More information?

If you want additional information regarding the resources the Marine System Analysis Group, please feel free to contact Bengt Liljebladh.