Smoke plumes from Mexico have traveled as far north as Wisconsin and the Dakotas, and as far east as Florida and out over the Gulf Stream.
Aerosols have a two-fold cooling effect on climate.
In the open atmosphere, they scatter and absorb incoming solar radiation, thereby reducing the amount of sunlight that reaches the surface. When clouds form in the polluted atmosphere, the clouds' droplets tend to be smaller and more numerous. Because polluted clouds are typically comprised of more densely-packed droplets, they are more efficient at absorbing and reflecting sunlight, again having a cooling effect on the surface. Aerosols represent one of the greatest areas of uncertainty regarding climate change, both on global and regional scales. Scientists do not fully understand the magnitude of their cooling influence on climate.