Anyway, Shawn, you do seem to be a real sceptic. Yes, NASA have been wrong, and Svalgaard too, but now they have an observable with a strong correlation to activity, so I don’t think they should be dissed on this until after the data come in.

Heck, David Archibald predicted that now was the time for solar minimum 2 years ago, so if the Sun is about to turn up, an itty bit, should we be surprised?

But the effect of this long solar cycle will be felt for many years to come…

If only it could affect Copenhagen December 2009!

Rich.

NASA has been wrong every step of the way predicting this sunspot cycle. I expect that trend to continue.

The first thought I had on seeing your charts is where there is a large change in your three sigma lines. Since there are so few data points the SD is sensitive to the outliers (2007-8) and the SD balloons where they “leave the pack” so to speak. So without those two the SD is probably uniform over the year.

I don’t like time behind or ahead as a comparison for sea ice because it will vary more with the rate than the difference in magnitude. When rates are high, the time difference will be small and vice versa. It’s the opposite of cars on a road race course where time difference is the preferred measure rather than than distance because distance varies with speed for cars with equal performance and driver skill. The cars will appear to bunch up in a corner and stretch out on the straights, even though the time difference is approximately constant.

Average loss for June 17 is 63,794 km2. So Based on figures as of today, the number of hours melt at the average rate to equal the difference between 2009 and each year (as at June 17) is:

2003: -88 hrs (2003 had more ice)
2004: -12 hrs
2005: 84 hrs (2005 had less ice)
2006: 138 hrs
2007: 49 hrs
2008: 42 hrs

No correction made for leap years.

http://science.nasa.gov/headlines/y2009/17jun_jetstream.htm?friend

I still think my NE passage being open is a dead cert though, and confident about the NW as well for another year of circumnavigation. If only I had a boat. I’d be Sir Andy by the end of the year !

Regards

Andy

Here are my anomaly plots: Rate Extent. The rate anomaly is calculated from the EWMA smoothed daily difference (alpha = 0.1), Mean and standard deviation from the 2003 to 2008 averages. I haven’t tried any statistical test, but eyeballing the variation in standard deviation, it’s not at all clear to me that there is a significant difference from day to day for most of the year, considering the small number of data points for each day. So the apparent shrinkage in the range of the difference may be more apparent than real. I don’t think we have enough data to be sure. Someone way better at statistics than I would have to determine how to test it. I could put it in something like an Xbar R control chart, but control chart statistics are designed for prospective not retrospective analysis.

I misspoke (miswrote?). The differences in the rate of change between years are smaller, not the magnitude. The differences in extent have also narrowed between 2009 and the other years.