Distant source of 1976 dustfall in Illinois and Pleistocene weather models

Very turbid skies were accompanied by dust deposition in western Illinois on October 15, 1976. Atmospheric circulation in central North America at the time was such that the dust was apparently transported to Illinois from sources in North Dakota or perhaps even southern Saskatchewan. This event indicates how some of the finer grained component of Pleistocene loesses of Illinois may have been derived from a distant source. Current models of Woodfordian atmospheric circulation patterns portray mid-tropospheric and lower tropospheric circulation, cyclonic activity, and climatic tendencies during summer months that are similar to the conditions that prevailed during this particular dust event.