Gaussian equation for the concentration of SO2

Explain qualitatively how the following would change the calculated surface concentration of SO2 assuming a gaussian plume from a smoke stack that follows the gaussian equation for the concentration of SO2

i) The wind speed decreased.

ii) The wind speed increased.

iii) A stable temperature profile became unstable.

iv) An unstable temperature profile became stable.

v) The SO2 was absorbed by the ground when the plume reached the surface.