Acid Rain Transport

Once airborne, the sulfur and nitrogen oxides eventually come down in one form or another. Where they come down depends on the height of the smokestack and the prevailing weather conditions. In general, prevailing winds in North America transport pollutants from west to east or northeast. The nine largest coal burning states are in the Midwest and the Ohio River valley. It is estimated that two thirds of the acid rain in the Northeast and Eastern Canada comes from these sources.

Blue arrow shows the upper winds that travel from the west to the east or northeast. Winds travel from the mid-west to the northeast. In addition, a copper-nickel smelter in Sudbury, Ontario, just north of Lake Huron is the most significant sulfur oxide source in Canada. The winds may also carry the sulfur oxide clouds to the Northeast in the U.S. where it may be converted to acid rain.