It may be faster here to define a new variable lscale and do

[jedwards4b]

It may be faster here to define a new variable lscale and do

if(present(scale)) then
  lscale = scale
else
  lscale = 1.0R8
endif

in this way you avoid the if inside the loop which prevents vectorization.

Originally posted by @jedwards4b in https://github.com/ESCOMP/CMEPS/pull/129#discussion_r520611039