ōl
The modifier ōl refers to the top of something. This is related to the word sōlle ‘head’. Rā NP ōl is to the top of NP or over NP and rū NP ōl is from the top of NP or from above NP.
rājōl
rājōl is rā NP ōl without a specified location, and so means ‘to the top’ or ‘over’.
rūjōl
Likewise rūjōl is rū NP ōl without a specified location, and so means ‘from the top’ or ‘from above’.