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The CTD data were acquired when the RMT instrument was in the water. Data Acquisition: There is a FSI CTD sensor housed in a fibreglass box that is attached to the top bar of the RMT. The RMT software running in the aft control room establishes a Telnet connection to the aft control terminal server which connects to the CTD sensor using various hardware connections. Included are the calibration data for the CTD sensor that were used for the duration of the voyage. The RMT software receives packet of CTD data and every second the most recent CTD data are written out to a data file. Additional information about the motor is also logged with the CTD data. Data are only written to the data file when the net is in the water. The net in and out of water status is determined by the conductivity value. The net is deemed to be in the water when the conductivity averaged over a 10 second period is greater than 0. When the average value is less than 0 the net is deemed to be out of the water. New data files were automatically created for each trawl. Data Processing: 1. Adjustment of the net open time. If the net did not open when first attempted then the net was 'jerked' open. This meant the winch operator adjusted the winch control so that it was at maximum speed and then turned it on for a very short time. This had the effect of dropping the net a short distance very quickly. This dislodges the net hook from its cradle and the net opens. The scientist responsible for the trawl would have noted the time in the trawl log book that the winch operator turned on the winch to jerk the net. The data files will have started the 'net open' counter 10 seconds after the user clicks the 'Net Open' button. If this time did not match the time written in the trawl log book by the scientist, then the net open time in the CSV file was adjusted. The value in the 'Net Open Time' column will increment from the time the net started to open to the time that the net started to close. The pressure was also plotted to ensure that the time written down in the log book was correct. When the net opens there is a visible change in the CTD pressure value received. The net 'flies' up as the drag in the water increases as the net opens. If the time noted was incorrect then the scientist responsible for the log book, So Kawaguchi, was notifed of the problem and the data file was not adjusted. 2. Removing unused columns from the original log files. The original log files that were produced by the RMT software were trimmed to remove any columns that did not pertain to the CTD data. These columns include the motor information and the ITI data. The ITI data gives information about the distance from the net to the ship but was not working for the duration of the BROKE-West voyage. This trimming was completed using a purpose built java application. This java class is part of the NOODLES source code. Dataset Format: The dataset is in a zip format. There is a .CSV file for each trawl, 125 in total. There were 51 Routine trawls and 74 Target Trawls. The file naming convention is as follows: [Routine/Target]NNN-rmt-2006-MM-DD.csv Where, NNN is the trawl number from 001 to 124. MM is the month, 01 or 02 DD is the day of the month. Also included in the zip file are the calibration files for each of the CTD sensors and the current documentation on the RMT software. Each CSV file contains the following columns: Date (UTC) Time (UTC) Ship Latitude (decimal degrees) Ship Longitude (decimal degrees) Conductivity (mS/cm) Temperature (Deg C) Pressure (DBar) Salinity (PSU) Sound Velocity (m/s) Fluorometer (ug/L chlA) Net Open Time (mm:ss) If the net is not open this value will be 0, else the number of minutes and seconds since the net opened will be displayed. When the user clicks the 'Net Open' button there is a delay of 10 seconds before the net starts to open. The value displayed in the 'Net Open Time' column starts incrementing once this 10 seconds delay has passed. Similarly when the user clicks the 'Net Close' button there is a delay of 6 seconds before the net starts to close. Thus the counter stops once this 6 seconds has passed. Acronyms Used: CTD: Conductivity, Temperature, Pressure RMT: Rectangular Midwater Trawl CSV: Comma seperated value FSI: Falmouth Scientific Inc ITI: Intelligent Trawl Interface This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
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Oceanographic measurements around the 'BROKE-West' survey area along the Antarctic continental margin between 30 degrees and 80 degrees south were conducted aboard Aurora Australis cruise au0603 (voyage 3 2005/2006, 2nd January to 12th March 2006). A total of 120 CTD vertical profile stations were taken, most to within 15 m of the bottom. Over 2500 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate and ammonia), 18O, dissolved inorganic carbon, alkalinity, particulate organic carbon/nitrogen/silicate, dimethyl sulphide, and biological parameters, using a 24 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package, while 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. LADCP data are not discussed in this report. Note that the data processor was not a cruise participant, thus this report does not describe all details of the shipboard field data collection or the problems encountered. CTD station positions are shown in Figures 1a and b, while CTD station information is summarised in Table 1. Niskin bottle sampling at each station is summarised in Table 2. (see word document detailed below for figures and tables) Further information is available in a word document available as part of the download. This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
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The Acoustic Doppler Current Profiler (ADCP) data were acquired constantly over the duration of the Australian 2006 V3 BROKE-West survey. Data presented here are the results of 1/2 hour integrations of the cruise data from the start of the voyage in Fremantle, Australia, to the start of the return leg just north of Australia's Davis Station in Antarctica (-66.56S, 77.98E). North and eastward components of the current velocity are given for depths up to 300m below the surface along the ship track. Data Acquisition: The shipboard ADCP is a continuous broadband recording device that operates over the duration of the voyage, ensonifying the water column once a second. As the instrument is fixed to the ship, it has a range of approximately 250m deep. Data from the shipboard Ashtek 3 dimensional GPS system is used along with bottom tracking data (when the water is shallow enough i.e. less than 250m) and automatically integrated into ADCP ping data to provide absolute current velocities. Data Processing: The ship ADCP constantly and automatically collects and stores raw .rawdp binary files in ensembles of three minutes worth of pings. This is regularly automatically collated into larger .adp files containing data for several hours (200+ ensembles). This data are processed for use in analysis using specialist software provided by Mark Rosenberg (mark.rosenberg AT utas.edu.au) that integrates together data from the ADCP .adp files for periods (30 minutes in this case) over a give time (from cruise start to the 3-Mar-2006). This produces .any ASCII files. These ASCII files are read into the Matlab processing package using scripts provided by Sergeui Sokolov (sergeui.sokolov AT csiro.au) which then produces the .mat matlab data files covered by this metadata. ADCP data requires proper calibration with respect to ship motion, which were not carried out for this data set, and could cause significant change when processed properly after the voyage. Dataset format: The processed ADCP file is given in matlab .mat format. All 1/2 hour integrations of ADCP data for BROKE-West from 3 days (31-dec-2005) before departure from Fremantle, to the 3-Mar-2006 are included, each column in each matrix or array representing an individual 1/2 hour integration in chronological order. There are numerous gaps in the data that occurred when the ADCP crashed and was not immediately reset or when bad data prevented processing. The location can be identified by plotting a scatter plot of longitude vs latitude, and the times by plotting the julian date. The matlab variables contained in the BROKE_West_ADCP.mat file are contained inside the adcp structure: lon: Longitude (decimal degrees) lat: Latitude (decimal degrees) time: Each column gives the year month day and hour of collection of the corresponding columns in the other variables. depth: Depth of each corresponding velocity value for each 1/2 profile. 60 fixed bin depths are given for each profile. (meters) press: As for depth but given in db. (db) u: Absolute current eastward component in ms-1 for each depth and profile. v: Absolute current northward component in ms-1 for each depth and profile. unav: Ship absolute eastward component in ms-1 for each profile vnav: Ship absolute northward component in ms-1 for each profile jtime: Julian date for each profile (julian days) badvals: Indexes of anomolous latitude and longitude values Acronyms used: ADCP: Accoustic Doppler Current Profiler IASOS: Institute of Antarctic and Southern Ocean Studies CSIRO: Commonwealth Scientific and Industrial Research Organisation This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
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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).
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The Lowered Acoustic Doppler Current Profiler (LADCP) data were acquired while the Conductivity Temperature Depth (CTD) sensor was in the water during the Australian 2006 V3 BROKE-west survey. Data Acquisition: The LADCP is mounted on the CTD frame and is lowered through the water column from surface to bottom on each CTD cast. During the cast upward and downward facing sensor heads ensonify the water column with four beams per head, collecting the data necessary to calculate the vertical velocity of the LADCP on the CTD frame, as well as the northward and eastward components of the current relative to the LADCP for the entire water column. Once the LADCP has been retrieved, the data collected in the cast are downloaded to a PC as two raw binary .adp files, one for the upward looking head and one for the downward. This occurs for each CTD cast. The only modification to a normal CTD cast procedure for the LADCP is a 5 minute pause within 50 m of the sea floor on the upcast. This gives the downward sensor time to gather enough data for later determination of relative bottom velocity. The shipboard ADCP is a continuous recording device that operates over the duration of the voyage, ensonifying the water column once a second. It operates in a similar way to the LADCP, except that as it is fixed to the ship, it has only a range of approximately 250m deep. The ADCP data are necessary for final LADCP data processing. Similarly shipboard 10 seconds GPS records and CTD pressure data for the period of each cast is required for LADCP data processing. Data Processing: Once collected the upward and downward raw .adp LADCP files are subjected to fairly extensive processing using software written for the Matlab package, to produce the usable .mat data files given by this dataset. This software, written by Sergeui Sokolov (sergeui.sokolov AT csiro.au), and slightly modified for the 2005/06 V3 BROKE-west voyage by Andrew Meijers and Andreas Klocker combines the raw .adp files with the shipboard ADCP data, 10 second ship GPS data and CTD profile data. While the raw LADCP .adp files can be processed alone with minimal CTD data (date, start time, end time, start and end lat and long and max depth), they will only give current velocities relative to the CTDs frames motion. To gain an absolute profile the software identifies bottom and surface reflections, and uses this and ship ADCP and GPS data as boundary conditions for an integration of the velocity shear in the raw .adp files. The end result of processing is velocity in north and south components for each depth over the CTD cast. For more details refer to the above reference (Wijffels, et. al. 2005). Dataset format: The processed LADCP file (AU0603_LADCP_3_to_120.mat) is given in matlab .mat format, and before future processing with properly calibrated ADCP data, should be regarded as preliminary only. All CTD casts for BROKE-West are included, except for casts 1,2 and 119, where the LADCP was not used in the CTD cast. Casts 1 and 2 are not in the dataset, while 119 is represented by NaN (not a number) values. The absence of casts 1 and 2 from the data mean that care should be taken in attributing the data to the correct cast. Column one in each velocity matrix represents cast 3, not 1, and column 2 is cast 4 and so on up to column 118 representing CTD cast 120. On several casts the ADCP data were not available, meaning only part of the LADCP processing could be completed. This occurred for casts 5, 46, 91, 92, and 96, and data given here are unreferenced to a bottom velocity or ship track. Other errors occurred that meant that casts 68 and 115 could not be processed at all, and so data for these casts are represented by NaN values. Casts not present in dataset: 1,2 Casts represented by NaN values: 68,115 and 119 LADCP data created without ADCP input on casts: 5,46,91,92,96 (warning unconstrained values) The matlab variables contained in the file are: bindep: 20 depth levels in meters at which velocity data occurs for each profile. Each row of matrix represents a depth level, each column a CTD cast, ascending from cast 3 to 120. date: Start date of each cast (UT) (year month day) lat: Start latitude of each cast (decimal degrees) lon: Start longitude of each cast (decimal degrees) stationno: Last 3 digits gives the CTD cast number time: Start time of CTD cast (UT) of each cast (hours min sec) u_down: u (eastward) component of velocity in ms-1 for each bindepth and CTD cast, using only downward looking head data u_final: As for u_down but using data from both heads. This is the best estimate of velocity. u_up: As for u_down, but upward looking head data only. v_down: As for u_down, but northward component of velocity v_final: As for u_final, but northward component of velocity v_up: As for u_up, but northward component of velocity zbottom: Bottom depth in meters for each cast (m) Acronyms used: LADCP: Lowered Acoustic Doppler Current Profiler ADCP: Acoustic Doppler Current Profiler CTD: Conductivity Temperature Depth IASOS: Institute of Antarctic and Southern Ocean Studies CSIRO: Commonwealth Scientific and Industrial Research Organisation This work was completed as part of ASAC projects 2655 and 2679 (ASAC_2655, ASAC_2679).
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Underwater vocalisations of Weddell seals were recorded at Casey (1997) and Davis (1992 and 1997) Antarctica. The goal of the study was to determine if it would be possible to identify geographic variations between the Casey and Davis seals using easily measured, narrow bandwidth calls (and not broadband or very short duration calls). Two observers measured the starting and ending frequency (Hz), duration (msec) and number of elements (discrete sounds) of four categories of calls; long duration trills, shorter descending frequency whistles, ascending frequency whistles and constant frequency mews. The statistical analyses considered all calls per base, single and multiple element calls, and individual call types. Except for trills, discriminant function analysis indicated less variation between the call attributes from Davis in 1992 and 1997 than between either of the Davis data sets and Casey 1997. The data set contains measures from 2966 calls; approximately 1000 calls per base and year. Up to 100 consecutive calls were measured from each recording location per day of recording so the data set indicates the relative occurrence of each of the call types per base and year. There were very few ascending whistles at Casey. All of the trills and mews contained a single element. This data set was published in Bioacoustics 11: 211-222. The fields in this dataset are: Observer Station Location Time Call Number Call Type Frequency Duration Elements Overlap In 2011, another download file was added to this record, providing recording locations made during the project in 2010. Furthermore: In 1997 Daniela Simon made some opportunistic recordings for the project near Casey. The recording locations were: Berkley Island 110 38'E, 66 12' 40"S Herring Island 110 40'E, 66 25'S O'Brien Bay 110 31'E, 66 18' 30"S Eyres Bay 110 32'E, 66 29" 20"S The Davis sites: IN 1990 THERE WAS ONLY ONE RECORDING SITE - 78 12.5' E, 68 31.6' S IN 1997 RECORDINGS WERE MADE AT THE FOLLOWING SITES EAST SIDE OF WEDDELL ARM - 78 07.55' E 68 32.17' S PARTIZAN ISLAND - 78 13.66' E 68 29.57' S LONG FJORD - 78 18.95' E 68 30.24' S TOPOGRAV ISLAND - 78 12.40' E 68 29.33'S OFFSHORE - 77 58.73'E 68 26.35'S TRYNE BAY - 78 26.25'E 68 24.87'S LUCAS ISLAND - 77 57.00'E 68 30.36'S WYATT EARP ISLANDS - 78 31.51'E 68 21.31'S ================================================================================ The attached document is "a listing of the Weddell seal breeding locations near Mawson where Patrick Abgrall in 2000 and Phil Rouget in 2002 made underwater recordings". The sound recording effort in 2000 was not as high as it was in 2002, hence fewer locations are listed. The Abgrall sites are referred to in the paper 'Variation of Weddell seal underwater vocalizations over mesogeographic ranges' that Abgrall, Terhune Burton co-authored, published in Aquatic mammals in 2003. This paper also refers to the Casey and Davis sites above. The Rouget sites relate to the metadata record 'Weddell Seal underwater calling rates during the winter and spring near Mawson Station, Antarctica' Entry ID: ASAC_1132-1 In general the seals can create breathing holes in areas where tide cracks form, namely close to grounded icebergs, the shoreline and islands. I doubt that they could/would create breathing holes through solid 2 m ice.
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Metadata record for data from ASAC Project 2337 See the link below for public details on this project. ---- Public Summary from Project ---- The experimental krill research program is focused on obtaining life history information of use in managing the krill fishery - the largest Antarctic fishery. In particular, the program will concentrate on studies into schooling, growth and ageing of krill. From the abstracts of some of the referenced papers: Nucleic acid contents of tissue were determined from field-caught Antarctic krill to determine whether they could be used as an alternative estimator of individual growth rates which can currently only be obtained by labour intensive on-board incubations. Krill from contrasting growth regimes from early and late summer exhibited differences in RNA-based indices. There was a significant correlation between the independently measured individual growth rates and the RNA-based indices. There was a significant correlation between the independently measured individual growth rates and the RNA:DNA ratio and also the RNA concentration of krill tissue, although the strength of the relationship was only modest. DNA concentration, on average, was relatively constant, irrespective of the growth rates. The moult stage did not appear to have a significant effect on the nucleic acid contents of tissue. Overall, the amount of both nucleic acids varied considerably between individuals. Nucleic acid-based indicators may provide information concerning the recent growth and nutritional status of krill and further experimentation under controlled conditions is warranted. The are, however, reasonably costly and time-consuming measurements. Growth rates of Antarctic krill Euphausia superba Dana in the Indian Ocean sector of the Southern Ocean were measured in 4 summers. Growth rate was measured using an 'instantaneous growth rate' technique which involved measuring the mean change in length if the uropods at moulting. In the first 4 days following collection mean growth rates ranged from 0.35 to 7.34% per moult in adults and 2.42 to 9.05% in juveniles. Mean growth rates of adult and juvenile krill differed between areas and between the different years of the investigation. When food was restricted under experimental conditions, individual krill began to shrink immediately and mean population growth rates decreased gradually, becoming negative after as little as 7 days. Populations of krill which exhibited initial growth rates began to shrink later than those which had initially been growing more slowly. Data were collected on growth rates of krill. These data were collected as part of ASAC projects 34, 1074, 2220 and 2337. ASAC_34 - Ecophysiology of Antarctic Krill 'Euphausia superba' ASAC_1074 - Seasonal growth in krill ASAC_2220 - Collection of live Antarctic krill ASAC_2337 - Experimental studies into growth and ageing of krill The fields in this dataset are: Field season (eg FS9596 = Field Season 1995-1996) Area (eg Indian Ocean) Cruise Month Date Latitude Longitude Total Number of Krill Dead Krill Moulted Krill Experiment ID Station ID Sample ID Sex Growth (IGR%) (% growth at time of moulting) Uropod Size (mm) Days after capture (when moulted) Standard length
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This dataset contains locations of sampling sites for ASAC project 40 on voyage 3 of the Aurora Australis in the 2004/2005 season. Samples were collected between December and February of 2004/2005. It also contains information on chlorophyll, carotenoids, coccolithophorids and species identification and counts. Public Summary from the project: This program aims to determine the role of single celled plants, animals, bacteria and viruses in Antarctic waters. We quantify their vital role as food for other organisms, their potential influence in moderating global climate change through absorption of CO2 and production of DMS, and determine their response to effect of climate change. For more information, see the other metadata records related to ASAC project 40 (ASAC_40). There are three spreadsheets in this download file - one for the CLIVAR I9 transect, and another for a survey in the region of the Princess Elizabeth Trough. A third spreadsheet contains pigment data. Each spreadsheet contains several worksheets. PET - CTD Station details, CTD profiles, CTD Surface Samples. I9 - CTD Station details, CTD profiles, CTD Surface Samples, Transect Surface Samples. CLIVAR_CTD_Pigs_CHEMTAX - Pigment data: Concentrations of various pigments (ug/L) analysed by HPLC (see protocol); Interpretation: Interpretation of pigment data using CHEMTAX to estimate the amount (ug/L) of chlorophyll a present in a range of algal types. There is also a word document detailing some of the HPLC procedures used. The fields in this dataset are: Station Latitude Longitude Time (Universal Time) Sounder depth Sounder offset Bottles Depths (dB) Label Fmax Tmin HPLC Fluorescence FCM Visc/TEP Phyto ID Lugols Glut Bacteria Water Temperature Salinity Conductivity Net Sample Depth (m) Species Chlorophyll a Pigments HPLC
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Microsoft Access database containing a compilation of CTD data collected in the Southern Ocean from Australian Antarctic Division (AAD), Antarctic Climate and Ecosystems Co-operative Research Centre (ACE CRC) and Hydrographic Atlas of the Southern Ocean (SOA) data sources. This SOA data contains discrete CTD (Conductivity, Temperature and Depth) station data along with a 1 x 1 degree gridded CTD data set interpolated in space and time. Parameters include pressure, temperature, salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, and silicate). Ocean Tools software developed by AAD is available in conjunction with this database to manipulate, extract and visualise data (including station map, transect selection, xy plots, vertical cross sections, geostrophic velocity/transport calculations). The download file contains an access database of the compiled CTD data, a word document containing further information about the structure of the database and the data (AAD CTD Data.doc), and a folder of the original source data, including readmes providing reference details, and specific information.
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Oceanographic measurements were conducted along WOCE Southern Ocean meridional section SR3 between Tasmania and Antarctica from September to October 1991. A total of 36 CTD vertical profile stations were taken. Over 600 Niskin bottle water samples were collected for measurements of parameters including salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate), chlorofluorocarbons, and biological parameters, using a 24 bottle rosette sampler. The fields in this dataset are: oceanography ship station number date start time bottom time finish time cruise start position bottom position finish position maximum position bottom depth pressure sigma-T temperature (C) (ITS-90) salinity (PSS78) density-1000 (kg.m-3) specific volume anomaly x 108 geopotential anomaly dissolved oxygen (mmol.l-1) number of data points used in the 2 dbar averaging bin standard deviation of temperature values in the 2 dbar bin standard deviation of conductivity values in the 2 dbar bin fluorescence photosynthetically active radiation CTD pressure (dbar) CTD temperature (C) (ITS-90) reversing thermometer temperature (C) CTD conductivity (mS.cm-1) CTD salinity (PSS78) bottle salinity (PSS78) bottle quality flag (-1=rejected, 0=suspect, 1=good) niskin bottle number