Southern Ocean Time Series
The Southern Ocean Time Series site is comprised of a number of different instrumentation, each of which is designed to measure specific physical, chemical and biogeochemical parameters. A deep ocean sediment trap mooring collects samples of sinking particles in conical traps at several depths around 1000m, 2000m and 3800m. Also part of the mooring, an innovative zooplankton-excluding trap is located at approximately 1000m depth. Samples from these traps quantify the transport of carbon to the deep ocean in sinking particles, and thus the strength of the biological pump that removes CO2 from contact with the atmosphere and stores it in the deep sea.
Also forming part of the Southern Ocean Time Series is a Pulse biogeochemistry mooring. The mooring is equipped with a range of sensors to record waves, currents, temperature, salinity, oxygen, total gas tension, phytoplankton fluorescence, particulate backscatter and photosynthetically active radiation, as well as a sampler for the collection of weekly samples for dissolved inorganic carbon, alkalinity, nitrate, silicate, and phytoplankton identification measurements. It presently requires twice annual servicing and reports wave data from the surface float in real-time mode, with the other data and samples that are collected within the surface mixed layer near 40m depth, obtained on recovery.
Air-Sea Flux Stations
Moored at the Southern Ocean Time Series site, the Southern Ocean Flux Station measures real-time meteorological and oceanographic conditions at the sea surface which are then used to analyse air-sea fluxes of heat, momentum and mass. The station is equipped with two Air-Sea Interaction Meteorology (ASIMET) systems, along with Iridium modems for data transmission. Data are hourly averaged and transmitted every four hours. Each data transmission includes measurements of weather including wind direction and speed, relative humidity, air pressure, air and water temperature, sunlight and precipitation, as well as oceanographic measurements including salinity and conductivity.
The two deepwater arrays currently deployed and maintained by the Deepwater Moorings facility of IMOS consist of three moorings instrumented with conductivity-temperature-depth sensors and current meters. At the polynya array off the Adelie Land Coast in Antarctica, sensors on each mooring are located at four depths between the sea floor and 300m. Sensors are not positioned higher in the water column on these moorings to avoid any potentially damaging contact with icebergs. The sensors collect a time series of full-depth profiles of water velocity and discrete temperature and salinity measurements.
At the Indonesian Throughflow array in the Timor Sea north of Australia, temperature and salinity sensors collect data for the entire water column. Furthermore, current meters fixed to the moorings profile velocity data above 500m and point source velocity between 500m and 1200m depth.