I understand, thank you.

Ascend is more formal. It is also more specific. It has a very grand feel. Kings, queens and religious figures ascend to thrones and to the heavens and so on. I can't think of a non-physical thing that ascends. But all sorts of things rise (physical and non-physical): Sea levels rise. Unemployment rises. Crime levels rise. A dictator rises to power. A musician rises in popularity. A cake rises as it bakes. Hope that helps. Others here may offer more detail.