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Record Search Query: [Location: Location_Category='OCEAN', Location_Type='SOUTHERN OCEAN']
The maximum extent of sea ice in the southern hemisphere by day and by winter season
Entry ID: sea_ice_extent_winter


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Summary
Abstract: These data give the maximum extent of sea ice in the southern hemisphere by day and by winter season and the mean maximum extent by month.
Data cover the 1979/1980 to 2007/2008 seasons.

The data are available in csv files and, in the case of the mean monthly data, as point and line shapefiles.

Related URL
Link: GET DATA
Description: Download point for the seasonal data - csv file


Link: GET DATA
Description: Download point for the daily data - csv file


Link: GET DATA
Description: Download point for the mean monthly data - csv file, shapefiles, image


Link: GET DATA
Description: Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data


Link: VIEW RELATED INFORMATION
Description: Citation reference for this metadata record and dataset


Geographic Coverage
 N: -52.4626 S: -67.7571  E: 180.0  W: -179.0

Temporal Coverage
Start Date: 1978-10-26
Stop Date: 2009-05-16


Location Keywords
OCEAN > SOUTHERN OCEAN
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Science Keywords
CRYOSPHERE >SEA ICE >ICE EXTENT    [Definition]
CRYOSPHERE >SEA ICE    [Definition]
OCEANS >SEA ICE >ICE EXTENT    [Definition]
OCEANS >SEA ICE    [Definition]


ISO Topic Category
CLIMATOLOGY/METEOROLOGY/ATMOSPHERE
OCEANS


Platform
DMSP >Defense Meteorological Satellite Program    [Information]
NIMBUS-7    [Information]
SATELLITES    [Information]


Instrument
SMMR >Scanning Multichannel Microwave Radiometer    [Information]
SSMI >Special Sensor Microwave/Imager    [Information]


Quality
Methods
Sea ice extents were calculated from passive microwave estimates of mean sea ice concentration (Cavalieri et al., 1996 updated 2008; Meier et al., 2006 updated quarterly).

Seasonal maximum extent
A season was considered to extend from the 1st of July of one year to 30th of June of the next. The extent of sea ice for a season was computed by searching for all pixels that were covered by at least 15% sea ice during at least one month of the season. The maximum latitude of sea ice extent was then calculated in one-degree longitude sectors, with sectors centred on integer longitudes from 179W to 180E. Areas of open water fully enclosed within the sea ice were disregarded for the purposes of calculating maximum latitude. Isolated regions of ice lying to the north of the main ice pack were also disregarded if they were separated from the main pack by at least 2 degrees of latitude (there were only a small number of instances of this situation).

Daily maximum extent
The maximum latitude of sea ice extent was calculated from daily estimates of sea ice concentration. Due to the increased presence of false ice in daily data (compared to monthly), an additional filtering step was applied during the calculation of daily extents. This filtering removed any areas of sea ice that were isolated from the Antarctic continent and which were less than 10 pixels in extent. The maximum latitude of sea ice was then calculated along transects centred on each integer degree of longitude. The area of open water lying to the south of the ice edge was also calculated for each transect (expressed as a fraction of the total area between the ice edge and the coastline).


Access Constraints
The data is available for download from the URLs given below.


Use Constraints
This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=sea_ice_... when using these data.


Keywords
sea ice
sea ice extent
microwave
southern hemisphere


Data Set Progress
COMPLETE


Data Center
Australian Antarctic Data Centre, Australia    [Information]
Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: metadata at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia



Distribution
Distribution_Media: HTTP
Distribution_Size: 32 kb
Distribution_Format: csv
Fees: Free

Distribution_Media: HTTP
Distribution_Size: 312
Distribution_Format: csv, shapefile, png
Fees: Free


Personnel
BEN RAYMOND
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Phone: +61 3 6232 3336
Fax: +61 3 6283 2336
Email: ben.raymond at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


DAVE J. CONNELL
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


Publications/References
Cavalieri, D., C. Parkinson, P. Gloersen, and H. J. Zwally (1996), Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data., Digital media, National Snow and Ice Data Center, Boulder, http://nsidc.org/data/nsidc-0051.html, updated 2008

Meier, W., F. Fetterer, K. Knowles, M. Savoie, M. J. Brodzik (2006), Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data, Digital media, National Snow and Ice Data Center, Boulder, http://nsidc.org/data/nsidc-0051.html, updated quarterly

Creation and Review Dates
DIF Creation Date: 2009-10-02
Last DIF Revision Date: 2014-09-12


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