in|ho|mo|ge|ne|i|ty

in|ho|mo|ge|ne|i|ty «_IHN hoh muh juh NEE uh tee, -hom uh-», noun, plural -ties.

a difference or variation occurring in spatial matter, magnetic fields, and optical mediums: »

The theory is that high-frequency radio waves are scattered by pockets of inhomogeneity produced by turbulence in the atmosphere (Scientific American).