The season 2012 wrap-up

Full record:

Snow depths recorded by Snowy Hydro Ltd at Spencers Creek near Charlotte Pass, Australia

And anomalies from the mean curve:

Aus snow depth anomalies

And the trends:

Peak depth:


Season integral depth:


Season integral depth is my preferred index of season quality, because it incorporates the effects of season length as well as depth.  It’s the area beneath the annual snow depth curve, calculated by adding together the depths for each week of the year.  Think of it as the average season depth times the season length (from zero to zero); hence that unit “metre.weeks”.

And the decades:


And cycles, by Fourier analysis:


For context, I add background points from Fourier analysis of 100 randomly generated depth series with similar stats to ours, but with no cycles.  The real data plots well within the “random” range except right at 2 years.  So, to the extent that there is any cycle at all, it’s a very weak 2 year one.

2 comments to The season 2012 wrap-up

  • Michael

    Great analysis – view for australian skiing in next 20 years? Will the aussie alps become Dubai like snow parks?

  • Gerg

    Not in 20 years. At current decline rates we’re losing less than a centimetre a year in peak depth. That will accelerate of course, but even at 2 cm a year we would still manage about a metre on average by 2050. I think there will still be worthwhile ski seasons (resort and backcountry) in many years at that point. Wipeout seasons will become much more common of course.

    Note that the CSIRO study a decade ago was much more pessimistic. That is still considered the definitive study, but my analysis suggest that it will turn out to be too pessimistic. Regional climate change prediction has come a long way in that time (but has a way to go yet…).