Deep Water Arrays

What are Deep Water Arrays?

Deep Water Arrays observe deep ocean currents and properties needed to understand the role of ocean on climate and its variability. The arrays monitor ocean circulation and its variability around Australia, providing valuable estimates of the ocean to the regional and global circulation, heat and freshwater content and exchange. The information provided by Deep Water Arrays contribute to a global understanding of ocean dynamics and allow the establishment of reliable climate and ocean models.

Deep Water Arrays have been deployed at three sites including the Polynya off the Adelie Land Coast in Antarctica, the Indonesian Throughflow in the Timor Sea and the East Australian Current off the coast of Queensland.

Key Data Streams

East Australian Current (EAC) Array

The East Australian Current (EAC) deep water array is designed to monitor the mean and time-varying flow of the East Australian Current transport. The EAC is a complex and highly energetic poleward western boundary current system of the South Pacific subtropical gyre. It is the dominant mechanism for the redistribution of heat between the ocean and atmosphere in the Australian region by transporting heat from the tropical Pacific Ocean to the mid-latitude ocean and atmosphere. The EAC Array, consisting of 6 moorings is deployed from the continental slope to the abyssal waters off Brisbane.

Mooring Schematic 

 

Indonesian Throughflow (ITF) Array

The Indonesian Throughflow mooring array aimed to sustainably and directly measure the leakage of the Pacific thermocline and intermediate waters from the western equatorial Pacific into the South Indian Ocean in the two major passages – Timor Passage and Ombai Strait. The Indonesian Passages represent an important ‘choke point’ of the global ocean overturning circulation and the climate system. The mooring array monitors ~80% of the inter-basin exchange of mass, temperature and salt between the Pacific and Indian Ocean. Note: this array ceased in 2015.

Mooring Schematic

 

Mertz and Totten Polynya Arrays

The three moorings in the Polynya Array, off the Adelie Land Coast in Antarctica, were designed to monitor the transport and properties of Antarctic Bottom Water that outflow to the deep Southern Ocean from the Antarctic continental shelf. Initially, the moorings were deployed in the Mertz Polynya but following the calving of the Mertz Glacier in 2010 changes in the regional icescape made this region logistically infeasible. A one-year pilot deployment was undertaken in 2014 in the polynya near the Totten Glacier to assess this site for sustained observations. Note: this array ceased in 2015.

Mooring Schematic 

Dr Bernadette Sloyan
E:
Bernadette.Sloyan(at)csiro.au