Let's do this again. I was so busy building a green roof (still not finished), and devastated every evening afterwards, that I didn't get around to updating the previous PIOMAS October 2013 blog post. Here's take two (after that you can take five) with the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:
According to the PIOMAS model the sea ice volume minimum was reached on September 7th at 4942 km3, a magnificent 52% rebound from 2012 (3261 km3). It was still 4th lowest on record though, coming in 514 and 925 km3 behind 2010 and 2011 respectively. Larry Hamilton sent me an updated bar graph showing the data:
version with the calculated "expected" 2013 values (dotted
lines), based on the same date values of 1979-2011 and an exponential
A caveat from Wipneus: "Note that the statistical error bars are quite large."
The trend line stays well outside of the confidence range during the latter part of the melting season. The Arctic don't care much about statistics, I guess. But that don't mean statistics ain't useful.
For some more perspective here are two other Wipneus graphs showing how this year's minimum relates to the linear and the exponential trends of Arctic sea ice volume decline (click for a larger version):
The PIOMAS sea ice volume anomaly graph also shows that the trend hasn't deviated further from the linear downward trend although it's still almost 1 standard deviation below it:
Average thickness (crudely calculated by
dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT)) is still among the lowest years, although slightly higher now where it was slightly lower a month earler. That's probably because CT sea ice area numbers are higher as well, which means there's a lot of thin ice out there:
Here's average thickness for September 30th in metres, with change from last month between brackets:
- 2005: 2.04 (-0.29)
- 2006: 2.13 (-0.06)
- 2007: 2.04 (-0.07)
- 2008: 1.96 (-0.47)
- 2009: 1.79 (-0.25)
- 2010: 1.28 (-0.15)
- 2011: 1.25 (-0.15)
- 2012: 1.27 (-0.12)
- 2013: 1.31 (-0.03)
If you want to have a look at the data yourself, you can download the spreadsheet I use and update from GoogleDrive.
The same more or less goes for the thickness graph from the Polar Science Center 2013. This year is amongst the four lowest there as well:
I'm expecting more data to come out soon, but at least we now know what the minimum sea ice volume was for the 2013 melting season. All eyes will now be on where we go from here, to see what the effect of this rebound will be for the coming melting season.
Do we know? No. Will it be interesting? Yes.