Perhaps the value rather than the ranking is more relevant.
2D ratios = f(Ra, Re)
3D ratios = f(Rv, Rt)
Fitness Ranking --> f(f(Ra, Re), f(Rv, Rt))
EX:
Let f(Ra, Re) = avg(Ra, Re)
Let f(Rv, Rt) = avg(Rv, Rt)
Let f(f(Ra, Re), f(Rv, Rt)) = avg(Ra, Re) * avg(Rv, Rt)
2012: 1.035
2019: 1.185
2016: 1.175*1.19 = 1.398
Hi cognitive
I just took the simple average of the 4 ratios for each year. Those ratios are based on values not ranks.
I can see utility in separating out the 2D and 3D combined ratios. I don't see advantage of multiplying the 2D * 3D vs. to get the overall combined score vs. just taking the average of the 2D and 3D scores. They each have two components so every measure gets the same weight by using simple average. Same is true for multiplying. I don't think multiplying would change the combined rankings and the final value would be less intuitive, i.e. more difficult to relate to the individual component values. But if there is an advantage to multiplying 2D * 3D I will consider an explanation for what that advantage is and use if it makes sense to me.
I thought about differential weighting since Volume seems to me to be the best overall indicator for health of the ice. But every measure has its pros and cons.
Extent gets blown up and down by the wind, so in some sense isn't a strong indicator. But it is the only one that is directly lmeasured.
Area has more info, but in the full document I repeat cautions from NSIDC about Area getting fooled by melt ponds.
Volume would be the best if we had a direct measure, but we don't. We have the PIOMAS model which is an estimate subject to errors as are all model estimates.
Thickness as I understand it is extrapolated from a relatively small number of direct measures so also has estimate error.
If I sound like I know what I'm talking about, don't be fooled. This is just how it all looks to me from reading at NSIDC and PIOMAS sites and ASIF of course.
By the way, full document did not get the final corrections. Will try to get the finalized PDF version posted tonight. The tables shown in the post above have all the corrections I could find.
I hope to update all the estimates when the July PIOMAS Volume and Thickness data come out in early August. I wish there was daily update of PIOMAS Vol and Thick, or even weekly. Great to have Wipneus providing mid month Vol. Did not see his mid month Thickness value, so most recent I had was from way back in June 30.
One thing that jumps out to me is the notion that 2012 had help from 2010 and 2011 softening up the ice. Heading into 2012, 2011 and 2010 were #1 and #2 in the all time combined ranking. Heading into 2020, it looks like 2018 and 2019 will be #7 and #2 (and 2017 at #5). Less of a setup than 2012 had.
But apart from all the number crunching the big picture is obvious and alarming. The ship is taking on water, the house is on fire. Pick your favorite metaphor and talk about what you see in Neven's most excellent ASIF with people you interact with. Political action requires people talking about it as the necessary first step. Research shows most people never talk about the climate crisis. Politicians tell me they don't hear much about it from their constituents, and that only the squeaky wheel gets attention and action. As the AIDS activists realized, silence is death. It is already too late to prevent bad consequences, but we can prevent worse consequences. We have to try.
What else ya gonna do? (end of sermon).