For anyone wondering, I have confirmed this equation is at least relatively true, with:
ω(Φ) = A + Bsin2Φ
where A is the equatorial rotation and B is the latitudinal gradient of the rotation. This is all the information that I need, and was found in the article cited below.
K. J. Li, X. J...
I am doing a University lab project where I measure positions of sunspots (using images from NASA's SDO) and use them to calculate the rotation of the Sun. Currently, all is going well: I have the angular velocity of several sunspots at varying heights. However, I want to be able to find the...