Ls vs. Sol values
We have used a sol-based visualization instead of Ls based one. Here is
why:
Below is the data for N70° and S70°, above in sol based, below Ls based
x axe. If you look at the sol based diagram, you can see larger difference:
longer summer in the north, shorter in the south. The Ls based diagram
obscures this difference. (However, the diffrence is not very large)