Visualizing the Link Between Ice Extent and Volume

by Malte Humpert The Arctic Institute presents the latest addition to its library of interactive graphs for Arctic sea ice extent and volume. The scatter plot below visualizes the link between Arctic sea ice extent and volume. The graph depicts monthly sea ice extent and volume for 2006-2011 and the monthly averages for 1979-1990 and 1979-2000 as a reference point. A mouseover effect allows the user to retrive data points directly from the chart and to also highlight datasets by selecting a year in the legend. The graphs are based on the Sea Ice Index published by the National Snow and Ice Data Center and PIOMAS Daily Ice Volume Data published by the Polar Science Center. This chart can be found permanently at Arctic Sea Ice Extent and Volume above.

The graph shows the accelerating rate of decline of ice extent and, especially, ice volume. In contrast to ice extent, ice volume has declined dramatically over the past five years. The 2011 minimum ice volume was more than 50 percent below the minimum ice volume of 2005. Even in comparison to the record low ice extent year of 2007, ice volume decreased by almost 40 percent. The ice extent in 2007 and 2011 were roughly the same with 4.3 and 4.61 million square km, while ice volume decreased from 6.53 to 4.2 thousand cubic km. Ice volume data helps to put the recovery of sea ice extent since the 2007 minimum into perspective. Sea ice volume continues to decline rapidly and has occurred at an exponential rate since 1979. If this trend persists over the coming years we could experience an ice free Arctic Ocean by the summer of 2015. The graph indicating an exponential decline was originally published here.

	1979-1990		1979-2000		2006		2007
	Volume	Extent	Volume	Extent	Volume	Extent	Volume	Extent
January	25.26	14.86	24.48	15.07	19.36	13.6	18.38	13.77
February	27.90	15.64	27.14	15.81	22.08	14.42	20.86	14.53
March	29.87	15.75	29.08	15.97	24.08	14.43	23.03	14.65
April	30.88	15.00	30.06	15.19	25.11	13.97	23.76	13.87
May	30.28	13.60	29.46	13.74	24.31	12.62	23.08	12.89
June	27.45	12.16	26.50	12.32	20.82	11.06	19.11	11.49
July	21.22	10.10	20.15	10.32	14.60	8.67	12.04	8.13
August	16.28	7.67	15.22	7.86	10.37	6.52	7.58	5.36
September	14.92	7.04	13.92	7.26	9.11	5.92	6.53	4.3
October	16.15	9.29	15.19	9.41	9.84	8.33	7.13	6.77
November	18.69	11.31	17.78	11.50	12.30	9.84	10.47	10.05
December	21.79	13.36	20.92	13.50	15.09	12.27	14.24	12.39

	2008		2009		2010		2011
	Volume	Extent	Volume	Extent	Volume	Extent	Volume	Extent
January	18.58	14.05	18.85	14.08	17.48	13.8	15.93	13.55
February	21.58	15.01	21.74	14.85	20.11	14.59	18.90	14.36
March	23.86	15.22	23.83	15.14	22.43	15.11	20.84	14.56
April	25.00	14.42	24.96	14.57	23.24	14.7	21.75	14.15
May	24.10	13.19	23.87	13.4	21.20	13.11	20.17	12.79
June	20.50	11.36	19.70	11.46	16.33	10.82	15.63	11.01
July	14.06	8.99	12.81	8.8	9.68	8.36	8.90	7.92
August	9.15	6.05	8.30	6.28	5.63	6.01	5.05	5.52
September	7.25	4.73	6.98	5.93	4.59	4.93	4.20	4.61
October	8.31	8.42	7.71	7.52	6.10	7.71	5.52	7.1
November	11.76	10.62	10.86	10.27	9.32	9.88	9.03	10.01
December	15.20	12.52	14.29	12.51	12.72	12.02	12.56	12.38

Sources:

[1] Chart created by Malte Humpert with Google Charts based on data from Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 1979-2011. Sea Ice Index. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media. The data can be found here.)

[2] Chart created by Malte Humpert with Google Charts based on data from PIOMAS Daily Ice Volume Data. Schweiger, A. 2011. Arctic Sea Ice Volume Anomaly, Version 2. Seattle, WA: Polar Science Center, Applied Physics Laboratory, University of Washington. Data set accessed on 01/08/2012 at http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/.