New York City Skyline Disappears
June 29, 2001
How to make a city disappear! It's a magic trick worthy of the greatest magicians of all time! Come and see New York City disappear! These pictures show the view toward the Manhattan skyline (in the background - picture on top) from a web cam located about 7 miles away in Newark, NJ. The top picture was taken on a clear day in late March, and the bottom picture taken on a day with haze and smog in early April. The haze is caused by fine particles formed from combustion sources combined with smoke from local brush fires and forest fires. These combine to make New York City vanish from view. The mix of particles over New York can include carbon from motor vehicles, nitrates from combustion sources, and windblown dust. Sometimes nitrogen dioxide gas gives the haze a brownish tinge.
However, most of the haze is due to tiny particles that come from the sulfur in fuels used to generate electric power, heat our hot water and move our motor vehicles. These sulfate particles absorb water vapor from the air and grow to a size about the same size as the wavelength of visible light. Consequently, these particles scatter all the wavelengths of light, not just some, so the haze looks white. The EPA is working with states, local governments, national park and forest agencies and tribal governments on a program to reduce the haze in our national parks. This program will also mean that someday, when a city disappears, it will be because of fog, not pollution.