ascend vs rise up

ascend and rise up both are verbs.

Word	Noun	Adjective	Verb	Adverb
ascend	No	No	Yes	No
rise up	No	No	Yes	No

As verbs, rise up is a hyponym of ascend; that is, rise up is a word with a more specific, narrower meaning than ascend:

Other hyponyms of ascend include come up, rise, surface, uprise.

ascend (verb)	rise up (verb)
slope upwards	come to the surface
travel up	stand up on the hind legs, of quadrupeds
come up, of celestial bodies	take part in a rebellion; renounce a former allegiance
go along towards (a river's) source
move to a better position in life or to a better job
appear to be moving upward, as by means of tendrils
become king or queen
go back in order of genealogical succession