Snow depths have been recorded weekly by Snowy Hydro Limited at Spencers Creek near Charlotte Pass since 1954. This shows the downtrend in season integral snow depth. Integral depth is an overall index of season quality, incorporating effects from 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 this as the average season depth times the season length (from zero to zero); hence that unit “metre.weeks”.
(* the weekly resampled depths)
More: If you need a peer review-published version of this graph, there’s one by Ken Green at NPWS: Green, K. (2010), Alpine taxa exhibit differing response to climate warming in the Snowy Mountains of Australia (PDF), Journal of Mountain Science 7:167-175 doi: 10.1007/s11629-010-1115-2 (figure 3 top panel). He calls integral depth “snow amount”, and plots metre.days instead of metre.weeks. There’s also an updated and slightly clearer version in Green’s chapter in the recent Ten Commitments Revisited (2014 — Figure 10.1).
link doesn’t work – peer review-published version of this graph, there’s one by Ken Green at NPWS: Green, K
Thanks Jim; fixed, and clarified.