Short announcement: I've put up a widget from Skeptical Science in the right hand bar that shows the planetary heat/energy imbalance that is built up due to greenhouse gas emissions. Generate your own customizable widget here if you have some space on your blog.
Last month I wondered "if and how last week's steep drop on all sea ice extent and area graphs will translate into volume numbers". Eyeballing the PIOMAS volume graph it seems it had an effect there as well, but since then numbers have climbed a bit faster than 2010 and 2011, though well below the 2007 trend line again. The difference with 2012 has gone down from 2161 to 1787 km3.
Here's Wipneus' version with the calculated "expected" 2013 values (dotted lines), based on the same date values of 1979-2011 and an exponential trend.
A caveat from Wipneus: "Note that the statistical error bars are quite large."
I repeat what I wrote last month:
For the first time since 2008 the anomaly from the downward linear trend could get positive in weeks to come, depending on how much ice refreezes according to PIOMAS. This doesn't mean the linear trend is reversed. It means that the decrease could be regressing to the linear trend, instead of deviating from it and becoming more of an exponential downward trend.
Average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT)) is on a par with 2010 and 2011 again, but 2012 is still running well below:
Here's average thickness for November 30th in metres, with change from last month between brackets:
- 2005: 1.45 (-0.02)
- 2006: 1.55 (+0.10)
- 2007: 1.34 (+0.06)
- 2008: 1.33 (+0.03)
- 2009: 1.31 (-0.04)
- 2010: 1.17 (+0.07)
- 2011: 1.14 (+0.09)
- 2012: 1.06 (+0.10)
- 2013: 1.18 (+0.08)
As the Arctic is now more full than empty, average thickness will now start to increase again.
If you want to have a look at the data yourself, you can download the spreadsheet I use and update from GoogleDrive.
The thickness graph from the Polar Science Center shows the same thing, 2013 on a par with 2010 and 2011, with 2012 still running well below:
It seems the difference with previous low years has been getting smaller in the past month, with the sudden 'pause' in ice growth in the first two weeks bringing 2013 real close to 2010 and 2011. It remains to be seen whether the gap will become smaller or bigger.
And so we wait. Chris Reynolds has been doing some exciting stuff lately to keep us entertained. More on that later.
Andy Lee Robinson has also updated his PIOMAS video: