Date of this Version
Martz, Ryan, Adam Houston, and Matthew Van Den Broeke. The Impact of Urban Heat Islands on Convection Initiation. Undergraduate Honors Thesis. University of Nebraska-Lincoln. 2023.
Increasingly urban landscapes and growing urban populations make understanding the impact of cities on their local climates ever more important. One of these impacts is that of the urban heat island (UHI) on thunderstorm development. This study is the first to examine the effect of UHIs on convection initiation on a large scale. We looked at the distribution of thunderstorm initiation points near 18 cities across the central United States between 2005 and 2015. We used RAP model data to identify the steering winds associated with each storm to place them into a wind relative frame of reference, and then we used the Getis-Ord Gi* statistic to find statistically significant clusters of thunderstorm initiation. This analysis produced no finding of a statistically significant increase in storm initiation downwind of or anywhere around urban areas. However, a second analysis strategy of examining CI density downstream of cities led to statistically significant impacts, particularly at night and in the fall.