The first Sea Ice Outlook of this year has been published. The SIO is organized by the Sea Ice Prediction Network (as part of the Arctic research program 'Study of Environmental Arctic Change', or SEARCH), and is a compilation of projections for the September 2015 Arctic sea ice extent, based on NSIDC monthly extent values. These projections are submitted by professionals as well as amateurs (public outlooks).
Here's the summary for the June report:
The median Outlook value for September 2015 sea ice extent is 5.0 million square kilometers with quartiles of 4.4 and 5.2 million square kilometers (See Figure 1 in the full report, below). Contributions are based on a range of methods: statistical, numerical models, estimates based on trends, and subjective information. We have a large spread in the Outlook contributions, which is not surprising given the wide-ranging observed values for the September extent in the past few years. The overall range (excluding an extreme outlier) is 3.3 to 5.7 million square kilometers. The median Outlook value is up from 4.7 million square kilometers in 2014. These values compare to observed values of 4.3 million square kilometers in 2007, 4.6 million square kilometers in 2011, 3.6 million square kilometers in 2012 and 5.3 million square kilometers in 2014.
Read the entire report here.
And here's the figure showing all the projections (click for a larger version):
The September minimums for the last 10 years (in millions km2, found here):
Again, it's nice to see some people who comment here and /or on the Forum to have again submitted contributions, like Rennie, Cole, Hamilton, Dekker and of course Chris Reynolds. Chris' projection of 5.15 million km2 for the September average is right between that of Schröder's 5.1 million km2 - whose projection I discussed in this recent blog post concerning melt ponds during May- and that of Zhang's 5.2 million km2, based on the PIOMAS model. These are among the best sources of projections (melt ponds and ice thickness) in my opinion, and so Chris' projection looks well-based and solid for the time being.