Climbing into Atlantic isle (9)
I believe the answer is:
ascension
This might be a double definition.
'climbing' is the first definition.
(thesaurus)
'atlantic isle' is the second definition.
'ascension' can be an answer for 'isle' (I've seen this before). I am not sure about the 'atlantic' bit.
'into' acts as a link.
Can you help me to learn more?
(Other definitions for ascension that I've seen before include "religious feast" , "distance in hours measured by this, right?" , "Canonise on the way up to heaven" , "Canonises on Christ's way to heaven" , "Island in the South Atlantic" .)