Publication Date

Spring 2019

Advisor(s) - Committee Chair

Dr. Xingang Fan (Director), Dr. Rezaul Mahmood, Dr. Gregory Goodrich, Dr. Philip Silva

Degree Program

Department of Geography and Geology

Degree Type

Master of Science


Atmospheric motions resulting from rising airborne parcels help to scatter emissions, including PM, away from their sources, decreasing local pollution levels. However this pattern shifts during the wintertime, as cold air damming and inversion layers create stable conditions that limit the vertical transport of air masses. Both point and area sources of emissions currently dot the western United States and are responsible for the production of the vast majority of agricultural pollution in the region. At the same time, population-growth has resulted in an ever-increasing amount of urbansource emissions. The entrapment of PM, which are produced when a wide array of urban and agricultural emissions series are released onto a valley floor, aggregate until they become singular particles which vary in size and can negatively affect the human respiratory system. As such, this goal of this study was to investigate the processes that lead to poor wintertime air quality conditions in the Mountain West and primarily in Cache Valley, which experiences some of the worst air quality in the United States during the winter season. Several results, including the observation of chemical reactions such as the production of the NO3 radical, along with the discovery of significantly high levels of DMS in an area that is not known for its production, all suggest that the chemical behaviors of Cache Valley are rather complex and play a critical role in poor wintertime air quality conditions. Furthermore, the presence of DMS at such high concentrations could be due to its being produced on the valley floor. As such, we hope that these results will help in improving our understanding of the physical and chemical dynamics of the Valley during the winter season, which will in turn aid in our ability to forecast such conditions and also properly plan future industrial and commercial projects that will inevitably be introduced into the region as it continues to grow.


Atmospheric Sciences | Environmental Sciences | Environmental Studies | Other Oceanography and Atmospheric Sciences and Meteorology | Physical and Environmental Geography