Meteorology: Understanding the Atmosphere            Ackerman and Knox


July 16 was one of the most polluted days of 1999 in the northeastern United States. A week’s worth of pollution from the Midwest and the East Coast found its way into the high’s circulation. The pollution then traveled on the high’s anticyclonic winds and collected over New England and its coastline. This is seen in satellite images and ozone concentrations.

The image below is from the GOES-8 visible channel on 16 July 1999 at 3:45 pm EST. A map is given on one of the images for reference along with weather conditions at the time (H - Haze). You can get an idea of the poor visibility in the region of the haze by noticing how difficult it is to see Long Island N.Y. (you can see southern NJ).

Pollution affects aviators because polluted air is much harder to see through than unpolluted air, even in a cloudless sky. Ozone Pollution on the Day of the JFK Jr. Crash is shown below in an animation. Notice that the high concentrations are also correlated with time of day.

The animation of ozone on this day is from the Environment Protection Agency Web site at

8-hour Average Concentration

Ozone Animation
Friday, 16 Jul 1999


Note: Animation reflects 8-hour average concentrations, calculated from observed 1-hour data. Today's animation is available from