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CTD

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  • CTD casts were taken through holes in the ice floe at various locations during ice stations 3, 4, 6 and 7. Two Seabird 37M microcats were used. One microcat did not log time, whereas the other did. An Idronaut Ocean Seven 304 CTD (manufactured in Italy) was used during ice stations 7 and 8. CSV files are provided. A single file represents a set of casts at a single location. The files are organised in columns as: Column 1: Temperature (C) Column 2: Conductivity Column 3: Pressure Column 4: Salinity (ppt) Column 5: Date (DD MMM YYYY), UTC Column 6: Time (HH:MM:SS), UTC For the Seabird 37M (2006 model) belonging to Dr Hutchings, time on the microcat is set to UTC, to the second. For the AWI Seabird 37M (1999 model), time is not output. This microcat dribbled data to a laptop at 1Hz. Ice Station 3: A microcat was placed at about 7m below the surface (5m below the ice) at Ridge site 1. Salinity sensor was iced up on this cast Ice Station 4: Cast 1: 100m cast through the ROV hole on Oct 6th 10:30 UTC. Cast 2: 10m cast at the trace gas site, on Oct 8th 06 UTC. Cast 3: 100m cast at the trace gas site, on Oct 8th 09:30 UTC. Ice Station 6: Cast 1: 100m at ridge site 1 , on Oct 13th 03 UTC. Cast 2: 10m casts at Trace Gas site, on Oct 13th 04:30 UTC. F Note that salinity sensor was iced on 10m cast at trace gas site. Cast 3: Deployment at 7m depth at ridge site 1, on Oct 13th 06UTC. Cast 4: 100m cast at ridge site 1, on Oct 14th 23 UTC. Note that microcat stopped recording at about 65m in downcast. Ice Station 7: - CTD casts with Seabird 37M microcat: Cast 1: 100m cast, Transducer Hole A, at active ridge. 20th Oct 03:00Z. Power failed 60m into downcast. Cast 2: 30m cast, Y-axis 50m core hole. 20th Oct 05:15Z Cast 3: 40m cast followed by 100m cast. Y-axis 100m ADCP hole. 21st Oct 00:00Z. Power failed at 60m. Cast 4: 15m casts. Y-axis 50m core hole. 21st Oct 05:15Z Cast 5: ROV Hole. With Polly's pinger. 21 Oct 09:30Z. Power failure at 86m. - CTD casts with Gerhard Dieckman's Seabird microcat. Note this microcat does not output time, but dribbles 1Hz data. Cast 6: Transponder Hole near new ridge. 23rd Oct 06:30Z. Cast 7: Trace Metal / Bio site. 23rd Oct 07:30Z. Cast 8: At ROV Hole Ice Station 8: Synoptic (3 hourly) CTD casts Roster of CTD casts is contained in file 'CTD_time.xls'. This table is pasted below. Please note that the names of excel files containing the raw data are presented in this table. Filenames: Ice Station 3: Filename: 20121004/20121004_IceStation3_microcat_all.dat. Ice Station 4: Cast 1: Filename: 20121006_IceStation4_microcat_cast1.dat Cast 2: Filename: 20121008_IceStation4_microcat_cast2_gerhard.dat Cast 3: Filename: 20121008_IceStation4_microcat_cast3_gerhard.dat Ice Station 6: Cast 1: Filename: 20121013_IceStation6_microcat_cast1_ridge.dat Cast 2: Filename: 20121013_IceStation6_microcat_cast2_gerhard.dat Cast 3: Filename: 20121013_IceStation6_gerhardCat_ridge_052700.dat Cast 4: Filename: 20121014_IceStation6_microcat_ridge.dat Ice Station 7: CTD casts with Seabird 37M microcat: Cast 1: Filename: 20121020_IceStation7_microcat_transponder_newRidge.dat Cast 2: Filename: 20121020_IceStation7_microcat_50m.dat Cast 3: Filename: 20121021_Station7_100m.dat Cast 4: Filename: 20121021_Station7_50m.dat Cast 5: Filename: 20121021_Station7_ROVhole_plusPolly2_tryagain.dat CTD casts with the AWI Seabird microcat: Cast 6: Filename: 20121023_gerhardCat.dat Cast 7: Filename: 20121023_gerhardCat_hole2.dat Cast 8: Filename: CTD_jenny_20121023.xls Ice Station 8: Synoptic (3 hourly) CTD casts: The data files are: CTD_jenny_20121023.xls CTD_jenny_20121028.xls CTD_jenny_20121030.xls CTD_jenny_20121031.xls CTD_jenny_20121101(1).xls CTD_jenny_20121101(2).xls CTD_jenny_20121102.xls CTD_jenny_20121103.xls CTD_jenny_20121104.xls

  • We deployed CTD sensors on five of the SIPEX 2 ice stations for collecting temperature and salinity of the water column under the sea ice. This dataset contains the raw data as outputted from the CTD in Excel format, in English. The dates that the CTD were deployed are in the file names (i.e. 20121023 is October 23, 2012).

  • 3 CTD casts were conducted during a limited marine science voyage by the Nella Dan to Prydz Bay during the 1985-1986 summer Antarctic season. The voyage leaser was Tom Maggs, and the deputy leader was Peter Heyward. The ship followed the schedule listed out below: Hobart 29-Dec-1985 04-Jan-1986 Edgeworth David 13-Jan-1986 17-Jan-1986 Shackleton Ice Shelf Davis 21-Jan-1986 21-Jan-1986 Marine Science 22-Jan-1986 23-Jan-1986 Marine Science Prydz Bay Davis 24-Jan-1986 26-Jan-1986 Marine Science 27-Jan-1986 27-Jan-1986 Marine Science Prydz Bay Mawson 29-Jan-1986 01-Feb-1986 Davis 03-Feb-1986 04-Feb-1986 Mawson 06-Feb-1986 06-Feb-1986 Davis 09-Feb-1986 09-Feb-1986 Edgeworth David 13-Feb-1986 13-Feb-1986 Shackleton Ice Shelf Casey 14-Feb-1986 14-Feb-1986 Hobart 22-Feb-1986 24-Feb-1986

  • Multiple CTD (conductivity, temperature, depth) casts were deployed during the SIPEX II AAD Marine Science voyage in September-November 2012. The system uses a descending rosette capable of holding up to 24 CTD bottles. During this voyage the CTD rosette also housed two krill traps (using controllable lights) and two GoPro cameras contained in pressurised, waterproof containers that were used to monitor the krill traps and view objects both on the sea bed and in the water column. Some functions of the GoPro cameras could be controlled from within the ship using the same transmission cable used by the CTD system. These functions included being able to change the focus setting of the cameras or start/stop recording. More information about the krill traps and cameras is contained in the SIPEX II Bottom Krill dataset. When a bottle is 'fired' from the ship it briefly opens, draws in water samples and closes again. It is not reopened until it is brought on board the ship. Bottles are opened at different depths to obtain samples from these depths. The depths vary from cast to cast and so are recorded in the CTD Log sheets (contained in this dataset as PDF files). Only raw data is contained in this dataset. The raw data was used by a variety of experiments during the SIPEX II voyage to produce results applicable to each experiment. Thanks go to the P and O crew of the RV Aurora Australis for their assistance during CTD operations.

  • Peter Sedwick collected water column samples (6 depths, less than 350m) and measured dissolved iron in these samples, using specialised trace-metal clean techniques, at 9 stations along the SR3 transect between 47 deg S and 66 deg S. These are the first such data for this oceanographic sector during spring. The dissolved iron levels were generally very low (less than 0.2 nM nM) in the upper water column, particularly south of the Subantarctic Front, and surprisingly there was no evidence of significant iron inputs from melting sea ice in our study region. Ongoing work quantified various size fractions of dissolved iron as well as total acid soluble iron. In addition, Jack DiTullio collected water samples for measurements of five biogenic sulfur pools at most shallow water CTD casts. The sulfur pools measured include: dimethylsulfide (DMS), particulate and dissolved dimethylsulfoniopropionate (DMSP) and particulate and dissolved pools of dimethylsulfoxide (DMSO). Taken from the referenced paper: A shipboard-deployable, flow-injection (FI) based instrument for monitoring iron(II) in surface marine waters is described. It incorporates a miniature, low-power photoncounting head for measuring the light emitted from the iron-(II)-catalyzed chemiluminescence (CL) luminol reaction. System control, signal acquisition, and data processing are performed in a graphical programming environment. The limit of detection for iron(II) is in the range 8-12 pmol L-1(based on 3s of the blank), and the precision over the range 8-1000 pmol L-1 varies between 0.9 and 7.6% (n )4). Results from a day-night deployment during a north to-south transect of the Atlantic Ocean and a daytime transect in the Sub-Antarctic Front are presented together with ancillary temperature, salinity, and irradiance data. The generic nature of the components used to assemble the instrument make the technology readily transferable to other laboratories and the modular construction makes it easy to adapt the system for use with other CL chemistries.

  • This dataset contains CTD (conductivity, temperature, depth) data obtained from the ADBEX II (= SIBEX I) cruise of the Nella Dan, during Jan - Feb 1984. 22 CTD casts were taken in the Prydz Bay region.

  • 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 dataset contains CTD (conductivity, temperature, depth) data obtained from the Big ANtarctic Geological and Seismic Survey (BANGSS) 94/95 cruise of the Aurora Australis, during Feb - Apr 1995. 24 CTD casts were taken in the Prydz Bay region, as a supplement to the geology research program. This dataset is a subset of the whole cruise data. The fields in this dataset are: Pressure Temperature Sigma-T Salinity Geopotential ANomaly Specific volume Anomaly samples deviation conduction

  • This is a parent metadata record for work carried out as part of ASAC/AAS project 40. See the child metadata records for further information. More than 95% of the biomass in the Southern Ocean is microscopic - single celled plants, animals, bacteria and viruses. We are studying the factors that control their distribution and abundance - oceanographic and seasonal conditions, their physiology, and grazing - in order to model their vital roles as food for other organisms and their influence in moderating global climate change through absorption of CO2 and production of DMS. We are also addressing the changes expected in microbial communities through effects of climate change - global warming, sea ice retreat, ocean acidification and enhanced ultraviolet radiation. This project aims to determine the role of microorganisms in the Southern Ocean. The major objectives are to: * Identify and quantify key protistan components of the Southern Ocean ecosystem and study their autoecology. * Identify environmental and ecological processes that control abundance of key microbial components. * Determine interactions between key microbial components to quantify major pathways of carbon flow. * Determine the activity and viability of bacterioplankton and protists in the Southern Ocean. * Distinguish different microbial communities by identifying key taxa and associations so that processes such as primary production, respiration, grazing and particle flux can be readily parameterised in ecological models. * Determine the effect of elevated CO2 concentrations on microbial populations and processes. Taken from the 2008-2009 Progress Report: Progress against objectives: 1. Ongoing sampling from Astrolabe has continued, with 3 return voyages being sampled for phytoplankton species, chlorophyll a and other pigments, coccolithophorid counts and DNA profiles, in conjunction with measurements of CO2, ocean structure, fluorescence and ocean colour by CSIRO / CRC colleagues. 2. Three sets of minicosm experiments were conducted at Davis station with 7 staff spending 4.5 - 5.5 months on site. These experiments consistently found that acidification caused blooms of nanoplanktonic diatoms and increased bacterial activity, apparently by inhibition of microheterotroph grazers, at the expense of larger cells that are more readily ingested by grazers such as krill. We showed for the first time in Antarctic waters that pCO2 affects the structure and function Antarctic microbial communities in a way that may reduce food availability to large grazers. Over 100 cultures of "winners and losers" from such experiments were isolated and returned to Australia. These will form the basis for further physiological experiments including molecular assays. 3. Submission and acceptance of 8 papers from the BROKE-West cruise (5 as senior author). These showed the interactions between bottom-up (micronutient) top-down (grazing) control in structuring microbial populations in the marginal ice zone. Five biogeographic zones were identified on the basis of species composition, and the productivity was measured for each zone. Microzooplankton grazing experiments found that grazing within that microbial loop consumed a significant proportion of new productivity. In some areas later in the season, all productivity was consumed by microheterotrophs, rather than metazoans such as krill. A time sequence was identified for seeding and development of components of ice edge blooms, subsequent grazing and decline and a mechanism postulated for export of micronutrients (e.g. iron) by grazing and sedimentation that prevents subsequent development of surface water blooms and constrains populations to a deep chlorophyll maximum below the level of a nutricline. 4. Detailed analysis of greater than 30 strains of keystone species Emiliania huxleyi of two morphotypes in conjunction with Clara Hoppe (Masters student, Alfred Wegener Institute) and Suellen Cook (PhD student, University of Tasmania) showed consistent differences between strains in terms of pigmentation, responses to light and genetics. The two morphotypes appear to be adapted to different mixing regimes north and south of the Polar Front; the southern form may represent a new species. For a full list of references associated with this project, see the project link at the provided URL.

  • Regular Trawl At each regular trawl station a quantitative standard double oblique tow was conducted from the surface down to 200 m (or to within 10 m of the bottom at stations shallower than 200 m). Such a depth range is considered to be the best compromise between the time available for sampling and the likely vertical depth range of krill. During the hauls, ship speed was maintained at a constant 2.5 plus or minus 0.5 knots. Wire speed of 0.7 to 0.8 m/s during paying out and of 0.3 m/sec during hauling (approx. 0.5 m/s and 0.2 m/s respectively at vertical depth change rate). The net mouth angle is remarkably constant during hauling within the speed ranges given above. When the net reaches maximum depth, the winch was stopped for about 30 seconds to allow the net to stabilise before starting retrieval. When hauling, propeller thrust was turned off when the net reached a depth of 15 to 20 m; this was to minimise the effects of the propeller action on the net operation and avoids damage of the samples. Target Trawl Whenever interesting targets were seen on the echo-sounder, or large amounts of krill were required for any purpose, target trawls were performed. Once the position of the target was marked, the ship was turned and navigated to run over the target from direction required within navigation capacity. The ship speed was lowered down to below 2.0 knots before hitting the target, so that the net could be lowered down to the desired depth whenever the net reached the target. Fine adjustments were made throughout the trawl by monitoring the echo-sounder in the aft control room. For live krill target trawl, ship speed was kept as slow as possible to avoid any damage to krill. Sample processing for all regular trawl stations: RMT-8 1.Measure the total sample volume (Drain water, then measure using water replacement; mandatory only for the regular hauls) 2.Sort out all Antarctic krill and count their number. If the sample mainly consists of krill and the volume is more than ~1L, a known portion of the whole sample was sub-sampled for the further processing. 3.Stage (TL, Carapace Length, Maturity) of all krill (or subsample), up to 50 to 150 individuals, and digestive gland size (the longest axis) of up to 50 individuals were measured using digital calipers. 4.Other zooplankton groups were immediately sorted out from the catch and their numbers were recorded. Preservation of RMT-8 samples Krill (including those used for onboard demography measurements) were fixed in 10% formalin for their further analysis. Whenever excess amount of krill catch were made, they were sampled and frozen for POP (persistent organic pollutant) measurements, preserved in 80% ethanol for genetic analysis, and frozen under -80C/ liquid nitrogen for chemical analysis. Fish were preserved in formalin, EtOH, or frozen. Squids were preserved in ethanol. RMT-1 1.The whole sample was fixed with 10 % formalin. 2.If the sample volume was too large, then a known proportion of catch was randomly sub-sampled and fixed. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).