Keyword

EARTH SCIENCE > OCEANS > SEA ICE > ICE TEMPERATURE

15 record(s)
 
Type of resources
Topics
Keywords
Contact for the resource
Provided by
From 1 - 10 / 15
  • This dataset contains data relating to an experimental method in which sea-ice samples were measured in an S-band microwave waveguide. This was conducted as a part of the 2012 SIPEX 2 (Sea Ice Physics and Ecosystems EXperiment) marine science voyage. A specially designed waveguide apparatus was connected to an Agilent FieldFox Portable Network Analyzer. Small parallelopipeds (7 cm X 3 cm X 1.9 cm) of sea ice were cut with a hand saw in a specially designed jig which holds an initially cylindrical core. The samples were placed at the end of the waveguide, configured to measure the vertical component of the effective complex permittivity tensor, and microwaves of frequency 2.9 GHz were sent down the tube. The samples were sized precisely to fit snugly in the end of the waveguide in order to minimize spurious reflections. The FieldFox recorded the coefficients of the scattering matrix, from which the complex permittivity can be computed. Sample temperature was taken both before and immediately after insertion into the waveguide. In order to assess the presence of off-vertical components of the electromagnetic field and how they may affect the measurements, a second sample was prepared with an orthogonal orientation, adjacent to the first sample. The same microwave measurements were taken on the second sample, to be later correlated with those from the first sample. The samples were stored in the freezer for later crystallographic analysis, and subsequently melted for salinity measurements. Prior to melting the samples were measured using callipers to determine their dimensions precisely. Samples were measured along each face at their minimum and maximum point for their width in the direction of propagation. In most cases samples were measured in all dimensions for better error analysis. A thin vertical section, approximately 5mm thick, was taken from each microwave sample stored for analysis. These sections were placed between a pair of cross polarized plates and photographed. Photos of the crystallography cores can be found in the crystallography folder, in a sub folder titled microwave. Each photo also contains a tag indicating the core number, site taken, date, as well as a V or an H indicating whether the sample was used for measurement of the vertical (V) or off-vertical (H) response. The scattering parameters recorded by the Field Fox can be found in the Data folder. Each file is named according to the microwave core measurement it represents and whether the measurement was of the vertical (V) or off-vertical (H) response. Each contains a standard S11 scattering parameter, stored as a comma separated value (CSV) file. Raw data can be found in the raw folder, and data that has been processed for ease of Matlab import can be found in the Reformatted_for_matlab folder. This processing involves taking output data that by default has four entries in a single column vector and remapping the data to create a four column matrix, each with a single entry. Recorded values for each microwave sample can be found in the Master_Core_List.xls Excel spreadsheet, within the Microwave worksheet. This worksheet was generated directly from notebook data, and contains the date, core number, depth of interface between the two collected samples, the minimum, maximum, and average thickness along the axis of propagation, The recorded temperatures from before and after measurement, the salinity, and calculated brine volume fraction. Finally, the worksheet contains notes, and a column to indicate whether we believe this data is somehow bad. Measurement information for thicknesses along other axis than that of propagation can be found in notes, but this data may at some stage be incorporated into a separate column. Please see the notes section for reasons why a data point was determined invalid. Typically this was due to the corresponding sample breaking while cutting into the parallelepiped shape. Scans of the original notebooks containing measured salinity values, thicknesses, and temperatures from which the Permeability worksheet were created are provided in the notebooks directory.

  • During 1977, many measurements were made of the sea temperature and salinity near Mawson base, taking the readings through the sea ice. Readings for each site were taken at depths that were multiples of 5, usually down to 100m (where possible). Measurements are recorded in log books, archived at the Australian Antarctic Division. Logbook(s): Glaciology Sea Ice Temperature and Salinity, Mawson 1977 Book 1 Glaciology Sea Ice Temperature and Salinity, Mawson 1977 Book 2 Glaciology Sea Ice Temperature and Salinity, Mawson 1977 Book 3

  • Observations of the sea ice cover at Wilkes base in Autumn-Winter 1963. Includes water temperature, air temperature, wind speed and direction, cloud cover, relative humidity, and general notes. These documents have been archived at the Australian Antarctic Division.

  • This dataset contains sea ice surface brightness temperatures using a portable passive-microwave radiometer operating at 36Ghz-H,V mounted to the undercarriage of a Squirrel helicopter during SIPEX 2, 2012. This radiometer is the same sensor as satellite passive-microwave radiometer AMSR-E and AMSR2. Our passive-microwave radiometer is launched on the same helicopter as Jan Lieser's (RAPPAL), so please see the "SIPEX-2 RAPPLS Surveys (Radar, Aerial Photography, Pyrometer, and Laser Scanning system)" metadata file for details of the aircraft. The RAPPLS dataset also contains track (GPS position) and altitude data, which can be used in conjunction with this dataset. The CSV files in this dataset are the raw files as output by the sensor. These raw data files show only the relevant parameters (time and brightness temperatures).

  • A 9 cm diameter Kovacs corer was used to drill holes partially through the ice. The core was removed, creating a pressure head in the hole. Packers made of ABS tubing wrapped with foam to create a tight seal were inserted into the holes to block the horizontal component of flow. A "Levelogger", which is a pressure transducer for monitoring well-water, created by Solinst, was then inserted into each hole to record the change in water level over time. Each Levelogger was fitted into a plastic holder to keep it upright during measurement, which is a requirement for accurate data from the device. The temperature at the bottom of the core was measured immediately after removal, and the bottom 2 centimetres were removed for melting and subsequent measurement of salinity. The measurements of salinity and temperature enable calculation of the brine volume fraction. Solinst Levelogger software was then used to compensate for local barometric changes recorded using a Solinst Barologger. Following each measurement an auger was used to drill through the bottom of each hole to measure the ice thickness and freeboard in each hole. A full core was taken at each worksite for crystallographic study, immediately adjacent to where permeability measurements were taken. A temperature profile was taken on each of these cores immediately after extraction. Cores were then moved to a -20 degree C cold room for further processing. A thin vertical section, approximately 3mm thick, was taken from each of the cores stored for analysis. These sections were placed between a pair of cross polarised plates and photographed. Each photo was labelled with the core and date it was taken, and was photographed with a meter stick for scale. After the thin sections were photographed, the remaining samples were melted to measure salinity. Some of the melted sea ice was saved for later O18 analysis to distinguish samples containing snow-ice. Recorded values required to determine permeability are contained within the Master_Core_List.xls Excel spreadsheet, found in the Permeability worksheet. This worksheet is generated directly from notebook data, and contains the date, start and end time for each permeability record, the core number assigned, the depth of the partial sackhole, the levelogger serial number used, the station (site), the temperature 2cm from the bottom of the removed core, the bulk salinity from the bottom 2cm of the removed core, as well as the measured freeboard and thickness at each site. This worksheet also contains a column to indicate which crystal structure the crystallographic core taken from this site and depth had, as well as which crystallographic core this came from. Finally, the worksheet contains notes, and a column to indicate whether we believe this data is somehow bad. Please see the notes section for reasons why a data point was determined invalid. Typically was due to heavy rafting beneath the flow or too quick an influx of water to properly measure. All permeability data can be found both in the original binary .xle format used by Solinst levelogger software, as well as exported into comma separated value (CSV) files. These files are located in the datalogger_data directory. Binary files are contained in the raw folder, organised into sub folders by station number. The CSV files are located in the csv folder, again organised into sub folders by station number. Photos of the crystallography cores can be found in the crystallography folder, separated into subfolders labelled with the site and core number. Each photo also contains a tag indicating the core number, site taken, date, and what depth range this covers. Tags may not contain a depth range for cores less than 1 meter. Please see the meter stick in each photo for scale. Scans of the original notebooks from which the Permeability worksheet were created are provided in the scanned_notebook directory.

  • This data describe a set of sea-ice and seawater physical and biochemical parameters obtained from seawater samples and ice cores drilled from land fast sea ice in the vicinity of Davis Station, East Antarctica at six different dates (stations 1-6) during late Spring 2016. Stations 1: 16 Nov. 2016 Stations 2: 21 Nov. 2016 Stations 3: 23 Nov. 2016 Stations 4: 26 Nov. 2016 Stations 5: 29 Nov. 2016 Stations 6: 02 Dec. 2016 Parameters measured: - Temperature, salinity; - Iron: Dissolved (less than 0.2um), soluble (less than 0.02um) colloidal (between 0.02 and 0.2um) and Particulate fractions (greater than 0.2um); - Macronutrients: Nitrate (NO3), nitrite (NO2), silicate (Si), phosfate (PO4) and ammonium (NH4); - Chlorophyll-a (Chla); - Particulate Organic Matter: Particulate Organic Carbon (POC) and Particulate Organic Nitrogen (PON) SW0: seawater collected at the surface SW3: seawater collected at 3m depth SW10: seawater collected at 10m depth

  • This dataset contains data resulting from the measurement of brine samples extracted from the sea-ice during the 2012 SIPEX 2 (Sea Ice Physics and Ecosystems Experiment) marine science voyage. The Brine was collected from partially drilled holes in the ice using suction. In some of these cases the brine analysed came from holes which correspond to permeability measurements. In these cases a core number is associated with the brine data which will correspond to the core number in the permeability data set. Brine was also made on the ship by repeatedly freezing sea water collected from site 8. Measurements of the electrical permittivity of the brine were measured from 200MHz-4GHz with varying temperature and salinity. The measurements were carried out using the FieldFox portable network analyser from Agilent technologies along with the Agilent 85070e high temperature dielectric probe. Typically the brine was cooled and measured as the temperature changed over time once removed from a freezer. Some samples were measured before and after filtering out any biology that may have been present to see any biological effect on the electrical properties of the brine, in particular any effect extra cellular carbon may have. Measurements of the biology in the brine were performed by Sarah Ugalde please refer to the biophysical folder for further information and the data. The actual permittivity measurements can be found in the Brine_Frequency_Temp Excel file. In the file each set of measurements has its own tab. Each measurement has a temperature and salinity associated with it. For a variability study measurements were repeated on some samples in which case the tab contains the sample name as well as an index indicating which repetition the data corresponds to. For example Core 85 6 would be the 6th measurement for core 85. You will also find the Excel file Brine_Calibration_Record which logs each calibration preformed before each measurement. The calibration for a given brine measurement has the same name as that brine measurement so that they can be matched. The permittivity measurements for each frequency, salinity and temperature are given in the real (e') and imaginary part (e").

  • Skin temperature data over the East Antarctic pack ice zone were recorded by the RAPPLS airborne instrument package using a KT-19II infrared pyrometer. The KT-19II infrared pyrometer was manufactured by heitronics, and sees a spectrum of 8-12um. IR and location data were logged to a Windows PC using a serial port logger developed by AAD science technical support. Due to some logging issues, substantial post-processing work was done by the AAD sea ice science group to ensure that recorded temperatures were correctly geolocated. Skin temperature data were not collected on two flights: Alpha [12 September 2007] and Foxtrot [14 September 2007] On two further flights, data were collected but the raw log files were so badly munged that we could not confidently tie locations to temperatures. These were: Tango [30 September 2007] and Uniform [1 October 2007] The data are presented in .csv files for each flight showing time and date. lat, lon, recorded temp [deg K], temp converted to C. To visualise the data, .kmz files that can be viewed in Google Earth or NASA's worldwind virtual globes are provided, one for each flight. Skin temperature is represented by a coloured dot at each measurement point. Clicking on each poijt will show its location and recorded temperature. The description field of each .kmz file provides a colour scale.

  • Five (out of a possible 7) ice stations were sampled for the Main Biology Site, collected from -63.88S 119.9E off East Antarctic in September to November 2012 during the Sea Ice Physics and Ecosystems eXperiment (SIPEX) II. Sampled pack ice floes were several 100 meters to several kilometres apart, and indicated variation in the degrees of physical deformation and biological characteristics. The sampled sites were selected on each floe due to low snow cover disturbances, were level, and free from surface deformations (limited rafting). For the production and carbon allocation dataset, the bottom 2 cm of 3 x 5 - 8 (dependant on level of biomass) cores were collected and combined within a 4 m grid using a 9 cm diameter SIPRE corer. Biology was isolated from the ice by gently mixing with 0.22 micron filtered sea water collected from the site with a Niskin bottle, and pass through a sieve. The liquid was then analysed for bacterial and algae productivity. The corresponding dataset (P:\Data\ Copy of SIPEX C14_Ugalde_Raw Data_St 8) describes data (expressed in disintegrations per minute) directly input into an excel file from the scintillation counter measured on board the Aurora Australis. The additional dataset (P:\Data\ SIPEX C14_Chloro_SIPEXII_Updated to Station 8) describes data directly input into an excel file of volume filtered for chlorophyll analysis (expressed in mls) of both the ice and liquid fraction. For the Main Biology dataset, 6 cores were taken from the same site: Core 1: temperature profile Core 2: nutrients, extracellular polymeric substances Core 3 and 4: chlorophyll, pigments (HPLC), bacteria and cell counts Core 5: particulate organic carbon/nitrogen, dissolved organic carbon Each core was sectioned from the ice-water interface at 0 - 2 cm, 2 - 10 cm, and then the remaining core was quartered. Core 1 was discarded after the temperature profile was taken. Core 3 and 4 were slow-melted in at 6 degrees cold room with 0.22 micron filtered sea water collected from the site as above (200 ml per cm ice). Cores 2 and 5 were slow-melted as above without the addition of filtered sea water. Additional measurements included 5 replicates of snow thickness and freeboard level. After melting, samples were taken/filtered for the parameters above within 12 hours of melting. The corresponding dataset (P:\Data\Data Updated to Station 8\ Main Bio Data Sheet_SIPEX II_Updated to Station 8) describes descriptive and quantitative parameters of the above cores, directly input into a spreadsheet.

  • A times series of data was collected from coastal (land-fast) sea ice at Davis Station, Eastern Antarctica (68 degrees 34' 36" S, 77 degrees 58' 03" E; Figure 1) from November 16 to December 2, 2015. Sea ice temperature and salinity, as well as macro-nutrients (nitrate NO3-, nitrite NO2-, ammonium NH4+, phosphate PO43- and DSi), particulate organic carbon (POC) and chlorophyll a (Chla) in the sea ice were measured six times in 16 days of austral spring and early summer (Nov. 16, Nov. 20, Nov. 23, Nov. 26, Nov. 29, and Dec. 2; in days of the year, 320, 325, 327, 330, 333, and 336). Depths were measured from the top of the ice cores. Seawater below the ice was also sampled for comparison. Samples of snow, sea ice, brine and under-ice seawater were collected under trace metal clean conditions near Davis station during the transition of sea ice from winter to spring conditions (October 2015), on a regular basis (every 4 days) for 3 weeks. 6 sampling events were successfully achieved. The list of parameters collected during the fast ice study include in situ temperature, ice texture, pH, oxygen, iron and Chla, Br/I, carbonate, nutrients and POC, incubations with stable N and C isotopes. Samples are currently returning on V3 and will be analysed in the US, Belgium and Australia in the coming months. The biogeochemical observations will allow us to determine the roles of light versus iron in the initiation of the spring bloom in this region, and the role of the melting fast ice in fertilising the spring time primary production.