In this section:
Moorings
SAIMOS uses an array of mooring stations, continuously monitoring the physical and biological properties of water off the Continental shelf. Research focuses along the paths of the upwelled waters flowing onto the shelf in summer, and the density currents that flow out of the gulf during winter.
Two types of mooring instruments are used:
1) Acoustic Doppler Current Profilers (ADCP) are used to measure ocean currents between the ocean floor and the surface.
2) Conductivity, Temperature and Depth (CTD) sensor packages are used to measure Salinity, Temperature, Pressure, Oxygen, Turbidity (water cloudiness), Fluorescence (Chlorophyll concentration), and PAR (the amount of biologically important sunlight that penetrates the water column).
In the next stage of SAIMOS, 20 temperature and pressure data loggers will be attached to a number of moorings to provide enhanced resolution of the vertical temperature structure of selected water columns.
The data from these instruments is provided to IMOS and used to monitor variations in the currents, physical water properties, and biological productivity over time scales ranging from minutes to years. SAIMOS currently has more than two years of continuous data from the Reference station, as indicated by a red star on the map below.
The data is also used by SARDI Oceanography’s numerical modelling group to check and initialise computer models of the regional ocean biology and dynamics.
In addition, SAIMOS has a number of devices used to aid in the recovery of the moorings, including
• Coastal Acoustic Release Transponders (CARTs) which allow us to release the moorings remotely from depths of up to 600 m using an acoustic signal sent from the ship.
• SABLE satellite transmitters which alert us to a surfaced mooring by sending e-mails to SAIMOS personnel giving the GPS location of the mooring. This is especially important if a mooring releases prematurely.
• Novatech strobe/radio transmitters that transmit a radio signal and flash when the mooring surfaces. The strobe light is visible up to 5 km away at night.
Typical MRV Ngerin cruise plan used for SAIMOS surveys
The graph above illustrates the geographical extent of the SAIMOS field survey program. Red circles indicate where the moorings are, blue and green dots highlight physical and biological sampling locations. SAIMOS conducts up to nine sampling cruises annually.
The red star indicates the Reference station, from which SAIMOS has collected more than two years of continuous data (to June 2010).
