Metadata record for data from ASAC Project 2720 See the link below for public details on this project. The overall objective is to characterise Southern Ocean marine ecosystems, their influence on carbon dioxide exchange with the atmosphere and the deep ocean, and their sensitivity to past and future global change including climate warming, ocean stratification, and ocean ... acidification from anthropogenic CO2 emissions. In particular we plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass in the Australian Sector to investigate the effects of iron addition from natural sources, and CO2 addition from anthropogenic sources, on Southern Ocean plankton communities of differing initial structure and composition. These samples were collected on the SAZ-SENSE scientific voyage of the Australian Antarctic Program (Voyage 3 of the Aurora Australis, 2006-2007 season). SAZ-SENSE VOYAGE AU0703 ADCP DATA * The complete ADCP data for cruise au0703 are in the files: au070301.cny (ascii format) a0703dop.mat (matlab format) * The "on station" ADCP data (specifically, the data for which the ship speed was less than or equal to 0.35 m/s) are in the files: au0703_slow35.cny (ascii format) a0703dop_slow35.mat (matlab format) * The file bindep.dat shows the water depths (in metres) that correspond to the centre of each vertical bin. * The data are 30 minute averages. Each 30 minute averaging period starts from the time indicated. (so, e.g., an ensemble with time 120000 is the average from 120000 to 123000). * ADCP currents are absolute - i.e. ship's motion has been subtracted out. * Note that the top few bins can have bad data from water dragged along by the ship. * Beware of data when the ship is underway - it's often suspect. * Important data quality information can be found in the data report referenced above. * The figure a0703difship30.eps shows the speed difference between vertical bin 2 and all other bins, where the data have been divided up into different speed classes for ship speed. The apparent vertical shear for bins ~1-10, and below bin ~40, is an error, possibly due to acoustic ringing from an air/water interface in the seachest. Data where ship speed is 0 to 1 m/s does not show this error.

Metadata record for data from ASAC Project 2720 See the link below for public details on this project. The overall objective is to characterise Southern Ocean marine ecosystems, their influence on carbon dioxide exchange with the atmosphere and the deep ocean, and their sensitivity to past and future global change including climate warming, ocean stratification, and ocean ... acidification from anthropogenic CO2 emissions. In particular we plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass in the Australian Sector to investigate the effects of iron addition from natural sources, and CO2 addition from anthropogenic sources, on Southern Ocean plankton communities of differing initial structure and composition. These samples were collected on the SAZ-SENSE scientific voyage of the Australian Antarctic Program (Voyage 3 of the Aurora Australis, 2006-2007 season). SAZ-SENSE VOYAGE AU0703 CTD DATA Oceanographic measurements were collected aboard Aurora Australis cruise au0703 (voyage 3 2006/2007, 17th January to 20th February 2007) as part of the "SAZ-SENSE" experiment south of Tasmania, between 43 degrees and 55 degrees south. A total of 109 CTD vertical profile stations were taken to various depths, focussing chiefly on the upper water column. Over 1300 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate, ammonia and nitrite), dissolved inorganic carbon, alkalinity, particulate organic carbon/nitrogen/silicate, dissolved and particulate barium, thorium, dissolved organic carbon, ammonium, pigments, phytoplankton, bacteria, viruses, diatoms, amino acids, and other biological parameters (list incomplete), using a 24 bottle rosette sampler. Near surface current profile data were collected by a ship mounted ADCP. Data from the array of ship's underway sensors are included in the data set. This report describes the processing/calibration of the CTD and ADCP data, and details the data quality. An offset correction is derived for the underway sea surface temperature and salinity data, by comparison with near surface CTD data.

This metadata record is a 'Parent' metadata record for ASAC project 2720. See the link for the related 'Child' metadata records. The overall objective is to characterise Southern Ocean marine ecosystems, their influence on carbon dioxide exchange with the atmosphere and the deep ocean, and their sensitivity to past and future global change including climate warming, ocean stratification, and ocean acidification from anthropogenic CO2 emissions. In particular we plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass in the Australian Sector to investigate the effects of iron addition from natural sources, and CO2 addition from anthropogenic sources, on Southern Ocean plankton communities of differing initial structure and composition. SAZ-SENSE is a study of the sensitivity of Sub-Antarctic Zone waters to global change. A 32-day oceanographic voyage onboard Australia's ice-breaker Aurora Australis was undertaken in mid-summer (Jan 17 - Feb. 20) 2007 to examine microbial ecosystem structure and biogeochemical processes in SAZ waters west and east of Tasmania, and also in the Polar Frontal Zone south of the SAZ. The voyage brought together research teams from Australasia, Europe, and North America, and was led by the ACE CRC, CSIRO Marine and Atmospheric Research, and the Australian Antarctic Division. The overall goal is to understand the controls on Sub-Antarctic Zone productivity and carbon cycling, and to assess their sensitivity to climate change. The strategy is to compare low productivity waters west of Tasmania (areas with little phytoplankton) with higher productivity waters to the east, with a focus on the role of iron as a limiting micro-nutrient. The study also seeks to examine the effect of rising CO2 levels on phytoplankton - both via regional intercomparisons and incubation experiments. Available for download from this metadata record are various datasets collected from the voyage: - An image showing a map of the cruise track. - An excel document detailing hourly position checks of the ship. - An excel document detailing the event log for the voyage. - A word document detailing prospective papers produced from the voyage. Finally a link is available for users to access the special volume of publications produced as a result of this voyage.