Contents

Idea

The Arctic sea ice consists of polar ice packs:

Polar ice packs are large areas of pack ice formed from seawater in the Earth’s polar regions, known as polar ice caps: the Arctic ice pack or Arctic ice cap of the Arctic ocean.

Here is an map showing the decreases over a 30 year period with the minimum ice in red which happened in 2007:

Here is a graph of annual minimum Arctic sea ice area from 1979 to 2011, based on NSDIC? data. Click for details:

Here is a graph of the annual minimum Arctic sea ice volume each year from 1979 to 2011, based on data from

Pan-Arctic Ice Ocean Modeling and Assimilation System—click for details:

Here’s a graph of Arctic sea ice volume created by the PIOMAS team, perhaps showing almost the same data in a somewhat different way. Click to enlarge:

The blue line is the linear best fit, but you can see it’s been melting faster lately. Is this a glitch or a new trend? Time will tell.

2011 is considerably worse than 2007, the previous record-holder. Here you can clearly see the estimated total volume in thousands of cubic kilometers, and how it changes with the seasons:

Details

Current state

Here is an updated plot of the Arctic see ice anomaly upto 2013-07-31:

Sofar it looks more like a trend in the anomalie.So I am going to see if there are some follow up articles on this issue.

Report card

Arctic Report Card from NOOA 2011 (2 minutes) also under Creative Commmons licence:

Climate change effects

References

• Disabled by the Sage developers due to general misue but I will move to the new Sage cloud or another site which supports interactrivity in Sage apps. Sage Interactive explorer of arctic sea ice levels. Creative Commons SA by M. Hampton.

• Arctic sea ice, Wikipedia.

• Arctic Sea Ice, Neven’s blog.

• The impact of an intense summer cyclone on 2012 Arctic sea ice retreat, by Jinlun Zhang, Ron Lindsay, Axel Schweiger, and Michael Steele.

This model study examines the impact of an intense early August cyclone on the 2012 record low Arctic sea ice extent. The cyclone passed when Arctic sea ice was thin and the simulated Arctic ice volume had already declined ~40% from the 2007–2011 mean.

The thin sea ice pack and the presence of ocean heat in the near surface temperature maximum layer created conditions that made the ice particularly vulnerable to storms. During the storm, ice volume decreased about twice as fast as usual, owing largely to a quadrupling in bottom melt caused by increased upward ocean heat transport.

This increased ocean heat flux was due to enhanced mixing in the oceanic boundary layer, driven by strong winds and rapid ice movement. A comparison with a sensitivity simulation driven by reduced wind speeds during the cyclone indicates that cyclone-enhanced bottom melt strongly reduces ice extent for about two weeks, with a declining effect afterwards.

The simulated Arctic sea ice extent minimum in 2012 is reduced by the cyclone, but only by 0.15×106 km2 (4.4%). Thus without the storm, 2012 would still have produced a record minimum.