JPG File 5.16M

Figure 6.4
Meteorological conditions accompanying the haze shown in Figure 6.3 (color insert). (A) Barometric pressure at 12:00 GMT, April 26, 1990 (millibars). This pattern typifies the common summer pressure distribution known as the Bermuda High, with winds blowing clockwise around the center (H). Such a pattern would facilitate accumulation of atmospheric pollutants. AHN, Athens, Georgia; BNA, Nashville, Tennessee; CKL Centreville, Alabama; DAY, Dayton, Ohio; GSO, Greensboro, North Carolina; HTS, Huntington, West Virginia; JAN, Jackson, Mississippi; PAH, Paducah, Kentucky; PIT Pittsburgh, Pennsylvania (i>B) Surface relative humidity at 12:00 GMT on April 26, 1990. Although relative humidity is comparatively high throughout the eastern United States, fog development was possible only in the southernmost parts, excluding the possibility that aaerosols in Figuer 6.3 were due to fog. (From the National Climatic Data Center, 1998b.)