Urban Development in Air Pollution Basins: An Appeal to the Planners for Help

The air basin between the Mississippi River and the bluff in Illinois is of particular interest for this report. The autumnal temperature profiles were measured by a wiresonde. Each day through September and October had an inversion at dawn and/or dusk. During the entire three months, inversions 5° or more occurred at dawn 64% of the mornings, those 10° or more occurred 45% of the mornings; and those 15° occurred 23% of the mornings. Under intense inversions, the topography holds cool air in the basin like water in a saucer, and currents within this 200-ft air layer comprise a quasi-closed circulation system. A frequent pattern of air circulation involves a northwestward surface drift in the basin, with a southwest wind aloft and an updraft over St. Louis. This forms a horizontal semi-vortex along the river, concentrating the heavier particulates near East St. Louis and Granite City. Multiple evidence showed this pattern to exist one morning among four. Business interests would use the basin for industrial expansion, but air resource planners prefer to keep new air pollution sources out of this low land.