Hello guys ! Could you help me, please?

I have got a surface and it has a curve. Maybe formerly (but I am not sure) I make this surface from Spehere.


But now I have got really annoying probleme with this. Because when I cut the closed curve ( you can see at the top of the surface) from the surface I dont get close curve. that is unfortunately open. My exact probleme with this that I would like to "Bend" this inner curve with an individual one what is situated out of surface.