For each layer, compute the average density over grain size of all layers above, i.e. <rho/gs>_slab.
This variable has been found to characterize the cohesion of slabs: new snow slabs tend to consist of low density & large grains, and
more cohesive slabs of older snow tend to consist of higher density & smaller grains (Mayer et al, 2022 in review).
computeSLABrhogs(profile, implementation = c("pub", "literal")[1])snowprofile object with added layers column $slab_rhogs. Note that topmost layer is always NA.
snowprofile object
"pub" for <rho/gs>_slab, "literal" for 'mean density of slab over mean grain size of slab' <rho>_slab / <gs>_slab.
fherla