Do the UC schools pay attention to improvement curves in GPA into senior year, during admissions?

Basically I had bad grades in AP Calculus AB, and I am improving my GPA during senior year gradually, but are they even going to notice this?

I don’t believe they will know unless you tell them.

They make admission decisions primary through your junior year transcript - although they know your current/planned senior courses.

Decision process feels fairly structured:

https://admission.universityofcalifornia.edu/how-to-apply/applying-as-a-freshman/how-applications-are-reviewed.html

Now, there are at least two sections of the UC where you can tell this story - one of the 8 personal essay topics fits this story and there is also a “should we know anything else” prompt.

UC’s do not consider Senior year grades in their admission review. If you mentioned an upward grade trend in the additional comments or on one of your personal insight essays then it will be noted. 10-11th grades get you in and 12th grades will keep you in meaning that they will maintain your provisional admission.