Characterization of the regional haze in the southwestern United States

As part of project VISTTA, aircraft sampling flights over non-urban portions of Arizona and Utah were conducted on 6 days in June and July 1979. The spatial distribution of “regional haze” is mapped in terms of the particle light scattering coefficient. Fine particle elemental composition was obtained from impactor and filter samples integrated over each flight path. One sampling day, 6/29/79, is characterized by reduced visibility throughout the sampling region. Possible sources are discussed.