The Study of Urban Heat Islands in the Birmingham and Auburn-Opelika, Alabama Urban Areas, Using Satellite and Observational Techniques

Abstract

Urban heat islands (UHI) are created by cities because buildings, impervious surfaces, energy and transportation, and reduced amounts of evapotranspiration increase temperatures compared to their rural surroundings. Because of their thermodynamic nature, UHIs can exacerbate the effects of severe weather events including heat waves and heavy precipitation. It is important to understand the characteristics of city UHIs and how they modify the dynamism of urban areas. This study compared the UHIs of a large sized metropolitan area in Alabama (Birmingham) to a mid-sized urban area in Alabama (Auburn-Opelika). To conduct this research, remotely-sensed images as well as observational data were analyzed to determine the rural and urban temperature differences. Temperature-monitoring instruments called iButtons were installed around the cities for the spring and summer months of 2014 (1 March to 31 August) to record hourly temperature data in order to analyze temperature patterns and variability. The research objectives of this study are: a) to quantify magnitudes and intensities of the average monthly diurnal UHIs in Birmingham and Auburn-Opelika by measuring atmospheric temperature 6-8 feet above the ground (i.e. atmospheric UHI), using iButtons; b) to quantify the surface UHI of Birmingham and Auburn-Opelika using remotely-sensed images and compare it to the atmospheric UHI. This research is significant given the likelihood of extreme climatic events like hurricanes, heat and cold waves, and increased global temperatures as stated in the Intergovernmental Panel on Climate Change (IPCC) V report. The results of this research will highlight the importance of mitigation procedures such as increased vegetation, green spaces, energy-efficient building practices, and a reduction in emissions; all of which would ameliorate the UHI effects. These measures would make Auburn-Opelika and Birmingham more sustainable and habitable agglomerations.