CTD

The CTD is an instrument used to profile the conductivity, temperature and depth (CTD) of the water column.

What it's used for

The CTD (conductivity, temperature, depth) instrument can be used to gather a range of ocean data including salinity, density and sound velocity. Extra sensors can also be added to the CTD to measure other variables such as phytoplankton, oxygen fluorescence and turbidity.

How it works

The CTD is deployed over the side of the vessel to depths of 6000 m.

The CTD includes a frame/carousel, CTD instrument, various auxiliary sensors and water sample bottles (Niskin Bottles) that allow water to be collected for later analysis.

During ascent to the surface, the bottles on the CTD can be closed at predetermined depths, allowing scientists to collect water samples at regular intervals throughout the water column.

Key features

24 bottle carousel and frame

A cluster of 24 water sample bottles and sensors that is attached to a CTD.

36 bottle carousel and frame

A cluster of 36 water sample bottles and sensors that is attached to a CTD.

Trace metal CTD system

A specialised system that includes a trace metal clean winch with 12 bottle trace metal CTD. The system has a trace metal clean cable to 300 m which is connected to a cable that allows deployment to depths of 6000 m.

CTD deployment boom

The CTD laboratory on RV Investigator is on the starboard side and uses a boom to deploy the CTD out through a vertically opening hatch.

CTD Voyages

HEOBI: Heard-Earth-Ocean-Biosphere Interactions

Investigating the sources, mechanisms, and processes that supply iron to the Southern Ocean.

The whole enchilada

Study of the whole ocean ecosystem from production to predation in the Tasman Sea

Repeat survey of the International Indian Ocean Expedition line (IIOE-2)

A coupled bio-physical, ecosystem-scale, examination of the International Indian Ocean Expedition line.