The law of conservation of angular momentum states that in an isolated system that has no external torques, which the universe would be (according to the theory), the angular momentum would not change. (creationscience.com)
Both of those deviations, as in the case of the Hadley and polar cells, are driven by conservation of angular momentum. (en.wikipedia.org)
The model was based on the fact that as a large cloud of gas and debris begins contracting under its own gravity, conservation of angular momentum dictates that it will rotate faster and faster as it shrinks, much like a spinning skater who pulls in her arms in order to twirl at top speed. (scientificamerican.com)