Conductivity-Temperature-Depth (CTD) data collected on board icebreaker Oden during the Oden Southern Ocean 2007/2008 expedition
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These data were collected onboard the icebreaker Oden during the Oden Southern Ocean 2007/2008 (OSO0708) expedition and are published by the Swedish Polar Research Secretariat. Accompanying meteorological and location data are published at ECDS (https://ecds.se/dataset/meteorological-oceanographic-and-ship-data-from-antarctic-expedition-oso0708-nov-2007-jan-2008)
For further information on the specific research expedition see the metadata record or visit www.polarforskningsportalen.se.
For further information on the data, data collection, sensors, limitations or errors contact the data provider: datamanager@polar.se  
www.polar.se
Data are released on a Creative Commons by Attribution License 3.0 

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Files and naming convention:
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oso07_ctdXXXyyy.asc - Main file containing data from station number XXX (006-034) and cast number yyy (011-076).
Oso0708CTD_cast_list.txt - List of CTD casts for which data are included.
Oso0708CTD_log.csv  List of all CTD casts during the OSO0708 expedition.
Oso0708CTD.shp  Shape file of OSO0708 CTD locations.
Oso0708route.shp  Shape file of OSO0708 route.
Oso0708CTD.kml  Google Earth file of OSO0708 route and cast locations.

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NULL indicates no reading or missing data.

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File content
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oso07_ctdXXXyyy.asc
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Pressure - (decibar) Pressure from SBE CTD sensor (Digiquartz).
Temp - (C) Sea water temperature from SBE CTD sensor.
Cond - (S/m) Conductivity of seawater using SBE CTD sensor.
Chl - (mg/m3) Chlorophyll-a estimated from fluourescence (Wetlabs ECO-AFL/FL).
Depth  (m) Sea water depth.
Salinity  (psu) Salinity of seawater.
PotTemp  (C) Potential temperature of seawater.
Oxygen - (ml/l) Dissolved oxygen.

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Oso0708CTD_cast_list.txt
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Cast #  Cast number.
Station #  Station number.
CTD Type - Type of CTD configuration (see notes below for description).
UTC Date - Date in coordinated universal time.
UTC Time - Time of day in coordinated universal time.
Latitude - Latitude (ship position).
Longitude - Longitude (ship position).
CTD Depth - (m) Target sea water depth for CTD deployment.
Bottom Depth - (m) Sea water depth from ship echo sounder.
Location - Approximate location.
Notes - Notes about location, sampling or equipment.

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Oso0708CTD_log.csv
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Cast #  Cast number.
Station #  Station number.
CTD Type - Type of CTD configuration (see notes below for description).
UTC Date - Date in coordinated universal time.
UTC Time - Time of day in coordinated universal time.
Latitude - Latitude (ship position).
Longitude - Longitude (ship position).
CTD Depth - (m) Target sea water depth for CTD deployment.
Bottom Depth - (m) Sea water depth from ship echo sounder.
Location - Approximate location.
Notes - Notes about location, sampling or equipment.

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Notes
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These notes were finalized on May 3, 2012 by Sharon Stammerjohn (sharon.stammerjohn@colorado.edu)

On OSO0708, the CTD sensor package included SBE pressure, dual temperature/conductivity and dual dissolved oxygen. Sensors were pre and post-cruise calibrated by SeaBird. Post-cruise corrections were made based on post-cruise calibrations using standard SeaBird protocols. In the case of oxygen, an additional correction was made based on best fit to the oxygen titrated data (where a constant offset of 0.1111 was applied). For T/C/O2 dual sensor data, the secondary sensor data were deemed the most stable and are published here.

The final cast data include only the upcast (except for Cast 11; see list below). This choice was necessary given the noisy or unreliable data on the downcasts.  The bad downcast data were related to the difficult deployment conditions on the IB Oden. The CTD package was housed in a van on the bow of the ship (one deck above the waterline) and wheeled out to the A-frame for deployment. This was often a lengthy and cold operation, not ideal conditions for the conductivity and oxygen sensors in particular. Thus, it would often take the first 10s or 100s of meters for the sensors to stabilize before reliable data were obtained. If time had not been an issue, we would have preferred a deep soak (e.g., at 100m) and then commencing the full cast from near surface. But this was not possible, given the short length of the cruise and the many other sampling demands.

We also note that there were 3 different CTD configurations used during OSO0708, and their naming convention was as follows (as listed in the file called, Oso0708CTD_log.csv):

CNV:  Conventional CTD (w/Oxygen Senors to 2000m)
CNVV:  Conventional CTD w/ VPR (only to 1000m)
TMC:  Trace Metal Clean CTD  to ~780m (w/ Fluorescence, Transmissometer)

Unfortunately, the TMC package was lost at sea just before Cast 54. (See CTD log for full cast list.) Therefore, those data could not be post-cruise corrected, so they are not published here.  Thus, the cast numbers up to Cast 54 are not continuous, because the missing cast numbers were the TMC casts.  However, the TMC casts were almost always taken in the same locations as the 'conventional' CTD casts, thus they duplicate the spatial sampling presented here. Finally, the UTC date, time and lat/lon listed in the CTD log file are for the start of each cast.

Below is a list of additional bad data removed from some of the casts.

Cast11
- downcast only (erroneous data for entire upcast); spikes at 1-4m; removed

Cast12
- spike in salinity (too low) and oxygen (too high) at 1-2 m; removed

Cast39
- spike in salinity (too low) and oxygen (too high) at 3m; removed

Cast43
-spikes in oxygen at 1m; removed

Cast47
- spike in oxygen (too low) at 1-4m; removed

Cast51
-spikes in oxygen at 1m; removed

Cast65
-spikes in oxygen at 1-3m; removed

Cast66
-spikes in oxygen at 1-2m; removed

Cast67
-spikes in oxygen at 1m; removed

Cast68
-spikes at 4-5m; removed

Cast70
- spike in oxygen (too low) at 1m; removed

Cast71
-spikes in oxygen at 1m; removed

Cast73
-spikes in oxygen at 1m; removed


