Your access to IMOS Deep Water Mooring data discovery and exploration is through the Australian Ocean Data Network (AODN) Portal.

The data streams collected from sensor measurements and sample collections are suitable for obtaining frequently sampled surface and deep ocean properties that control the transfer of heat, mass and CO2 from the atmosphere to the upper ocean.

Sub-Antarctic Zone (SAZ) sediment trap mooring

The Sediment Trap data includes particle count data, velocity, temperature, pressure and conductivity from 1997 to present. These samples 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. Samples from the sediment traps are available now for studies of carbon flux to the deep ocean. Delayed mode data is available for all sensors and sediment trap collections after the mooring is turned around on a roughly annual basis.

Example of typical collections in the deep (3800m) trap cups at SOTS showing part of the seasonal cycle. 21 cups are collected at 3 depths each year. This material is sieved (1mm mesh) to remove zooplankton, and then dried and ground for chemical analysis. Image credit: Stephen Bray.

Pulse biogeochemistry mooring

The Pulse 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.

Data streams produced include; wave heights and spectra (obtained by integration of accelerometer data) for the study of wave influences on turbulence, deep ocean Temperature and salinity data to aid in the assessment of ocean warming below the depth of Argo observations and multi-frequency acoustic volume scattering data. It also collects water samples at approximately weekly intervals for measurements of nutrients, CO2, alkalinity, concentrations and identification of phytoplankton functional groups. The wave data from the surface floats is available in real time. All other sensor data and water samples are available in delayed mode after the roughly annual swapping of duplicate moorings at the site.

Example of sensor data from the Pulse mooring, showing hourly values for temperature and salinity at ~30m depth over 3.5 months from mid-Sept 2011 to the end of January 2012 showing the passage of 3 unusually warm and salty water parcels which influenced net community production and may have derived from the increasingly strong southerly extension of the East Australian Current (see Weeding and Trull, 2014 for expanded discussion).

Southern Ocean Flux Station

The Southern Ocean Flux Station is an open-ocean mooring that measures real-time meteorological and oceanographic conditions at the sea surface.  In particular, the station provides data on air-sea heat and moisture fluxes, which, when combined with meteorological data, are essential for climate change research.  The continuous time series provided by the air-sea flux stations are particularly important because many of the processes that control heat and moisture fluxes exchange show variability on a wide range of time scales. The mooring also carries sensors to measure pCO2, O2, and phytoplankton fluorescence, to both extend and provide backup to the Pulse platform.

Southern Ocean Flux Station data collection contains heat and mass fluxes at the sea surface. The observed meteorology, downwelling radiation, and sea water temperature and salinity at the surface are also included. 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.

Atmospheric and hydrographic observations at the SOTS station: (a) wind speed, (b) sea surface temperature (SST), (c) sea surface salinity, (d) heat flux, and (e) mixed layer depth (MLD). In all panels observations from 2011, 2012, and 2013 are shown in green, blue, and red, respectively. The bold black lines in Figures 4b, 4c, and 4e, indicate daily averages of the 2012 data, and in Figure 4c, the bold blue line indicates the annual mean salinity (Smean = 34.60) in 2012. The period of eastward drift (see Figure 1b) from 24 September to 31 December 2012 is indicated above Figure 4a. Figure above is from Shadwick et al., 2015.

For SOTS Bio-Argo profilers (mixed layer depth and oxygen) and ocean gliders please visit the Argo and Ocean gliders webpages.

Cited refs:

Shadwick, E. H., Trull, T. W., Tilbrook, B., Sutton, A. J., Schulz, E., and Sabine, C. L.: Seasonality of biological and physical controls on surface ocean CO2 from hourly observations at the Southern Ocean Time Series site south of Australia, Global Biogeochemical Cycles, 2014GB004906, 004901-004916, 10.1002/2014GB004906, 2015.

Weeding, B., and Trull, T. W.: Hourly oxygen and total gas tension measurements at the Southern Ocean Time Series site reveal winter ventilation and spring net community production, Journal of Geophysical Research - Oceans, 119, 348-358, doi:310.1002/2013JC009302, 002014, 2014.

Herraiz-Borreguero, L., and Rintoul, S. R.: Regional circulation and its impact on upper ocean variability south of Tasmania (Australia), Deep-Sea Research II, 58, 2071-2081, 2011.