File:NSIDC arctic sea ice extent since 1979.svg

Original file ‎(SVG file, nominally 810 × 540 pixels, file size: 37 KB)

This is a file from the Wikimedia Commons. Information from its description page there is shown below.
Commons is a freely licensed media file repository. You can help.

Summary

Description	English: Plot of arctic sea ice extent development between 1979 and 2023 in monthly mean values. For the determination of the "area" value, every pixel with a sea ice concentration > .15 is taken. The pixel area is multiplied with the concentration value derived from the passive infrared signal. For the "extent" value, the concentration value is taken as 1, so we basically get full area with >.15 concentration. Deutsch: Verlauf der Umrissfläche des arktischen Meereises in Monatsmittelwerten von 1979 bis 2023. Für die "area"-Daten werden alle Pixel mit einer Eiskonzentration > 0.15 genommen und deren Fläche mit der Eiskonzentration multipliziert. Für die "extent"-Daten wird diese Eiskonzentration =1 gesetzt - so erhält man die Gesamtfläche mit überhaupt irgendwelchem Eis.
Date	29 August 2010
Source	Own work
Author	Dominiklenne

Data source: Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 2002, updated until 2010. Sea Ice Index. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media. ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/. Corresponding website: http://nsidc.org/data/seaice_index/archives/index.html

For the area definition see: https://nsidc.org/learn/ask-scientist/what-difference-between-sea-ice-area-and-extent

Licensing

I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

File history

Click on a date/time to view the file as it appeared at that time.

	Date/Time	Dimensions	User	Comment
current	17:48, 23 October 2023	810 × 540 (37 KB)	Dominiklenne	update to october 2023
	21:07, 9 May 2023	810 × 540 (37 KB)	Dominiklenne	update to april 2023
	19:12, 4 March 2022	810 × 540 (36 KB)	Dominiklenne	update until february 2022
	00:39, 7 November 2020	810 × 540 (42 KB)	Dominiklenne	update until october 2020
	17:16, 27 October 2019	810 × 540 (45 KB)	Dominiklenne	data added until september 2019, year scale extended to 2030
	22:35, 30 October 2018	810 × 540 (47 KB)	Dominiklenne	data updated until september 2018
	22:44, 8 July 2017	810 × 540 (47 KB)	Dominiklenne	data updated until june 2017
	21:43, 22 July 2016	810 × 540 (47 KB)	Dominiklenne	data updated until june 2016
	21:43, 27 August 2015	810 × 540 (40 KB)	Dominiklenne	minor y scale change to the same as in https://commons.wikimedia.org/wiki/File:Plot_arctic_sea_ice_area.svg
	17:03, 27 August 2015	810 × 540 (40 KB)	Dominiklenne	update until 2015 / 07. Use of python matplotlip pyplot instead of Gnumeric. Slightly different y-scale for better exhaustion of plot area.