Things are getting really interesting now, with volume levels back to those of 2007, slightly above them even (43 km3), and over 2000 km3 behind last year's record low! It was 1768 km3 at the end of September (see previous blog post).
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."
The PIOMAS sea ice volume anomaly graph is now also getting very interesting:
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 (also see the Wipneus linear and exponential graphs I posted in the previous PIOMAS update).
Average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT)) is still on a par with 2010, but trend lines dropped a bit further in 2011 and 2012:
Here's average thickness for October 31st in metres, with change from last month between brackets:
- 2005: 1.47 (-0.57)
- 2006: 1.45 (-0.68)
- 2007: 1.28 (-0.76)
- 2008: 1.28 (-0.68)
- 2009: 1.35 (-0.44)
- 2010: 1.10 (-0.18)
- 2011: 1.05 (-0.20)
- 2012: 0.96 (-0.31)
- 2013: 1.10 (-0.21)
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:
There's a lot more ice right now in the Arctic than there was in previous years around this date and I'm curious to see how things develop all the way up to the maximum. 2013 volume has shot up quickly, not having to deal with all the warmth that had to be released in previous years (it was a relatively cold summer). On the other hand, this also means the Arctic Ocean is quickly covered with a layer of ice that insulates it.
Another point to keep in mind, is that there may be more ice in total, but this doesn't tell us much about the thickness distribution or quality of all that ice. It's a recovery all right, but it remains to be seen if the recovery will develop further (also see Chris Reynolds' latest entry on his Dosbat blog: The 2013 Sea Ice Rebound (that never was)).
Right now I wonder if and how last week's steep drop on all sea ice extent and area graphs will translate into volume numbers:
More info next month!