Mertz Polynya Experiment, 1998-2000
This experiment was undertaken by the Cooperative Research Centre for the Antarctic and Southern Ocean Environment (Antarctic CRC), based in Hobart, Australia. Oceanographic measurements were conducted in the vicinity of the Mertz Polynya, encompassing two consecutive seasonal cycles from 1998-2000. These measurements comprised CTD and mooring work over three Antarctic marine science cruises. The primary oceanographic aims of the experiment were:
- To monitor over one or more seasonal cycles the thermal structure of the Mertz Polynya and the outflow of bottom waters from the Mertz Depression lying adjacent to the Mertz Glacier, thought to be the source of Adelie Land Bottom Water.
- To assess the time variability of bottom water formation and the processes involved in bottom water formation and to estimate the total formation rate of bottom water in the Mertz Polynya.
- Calculate heat and brine fluxes from a closed volume on the shelf.
- Assess heat and momentum exchanges between shelf and slope waters.
Marine science cruises AU9807, AU9801, AU9905 and AU9901 were conducted aboard the Australian Antarctic Division vessel RSV Aurora Australis. Cruise TA0051 took place aboard New Zealand's National Institute for Water and Atmospheric Research (NIWA) vessel RV Tangaroa.
In the southern winter of 1999, a total 92 CTD/LADCP vertical profile stations were taken, most to within 20m of the bottom, with 3 laps completed around the boundary of a box adjacent to the Mertz Glacier. Over 700 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients, oxygen 18, dimethyl sulphide and biological parameters using a 12 bottle rosette sampler mounted on a 24 bottle frame. Additional CTD vertical profiles were taken in April 1998, July 1998 and February 2000. Near surface current data were collected on all cruises using ship-mounted ADCP. Two mooring arrays comprising thermosalinographs, current meters and upward looking sonars were deployed in the region of the Polynya. The first array of seven moorings was deployed in April 1998. The second array of four moorings was deployed in the winter of 1999. All eleven Polynya moorings were recovered in February 2000. Two sediment trap moorings were also deployed in the winter of 1999, in the Subantarctic zone, with additional CTDs taken at the two locations.
Information about this data set has been taken from the following publication:
Rosenberg, M., Bindoff, N., Bray, S., Curran, C., Helmond, I., Miller, K.,McLaughlan, D. and Richman, J. (2001) Mertz Polynya Experiment, marine science cruises AU9807, AU9801, AU9905, AU9901 and TA0051 - oceanographic field measurements and analysis. Antarctic Cooperative Research Centre, Research Report No. 25, June 2001, Hobart, Australia, 89 pp.
If you require additional information about this data set, please send an email to: mark.rosenberg@utas.edu.au