Sky Brightness in Texas: A Comparative Study Between International Dark Sky Places and Control Communities
Jackson, Amy P.
Dark Sky International’s Dark Sky Places program recognizes places that use dark sky friendly lighting practices to mitigate the negative impacts of light pollution. Dark Sky International promotes the use of outdoor lighting that mitigates the impact of light pollution through their International Dark Sky Place program which designates parks, communities, urban places, reserves and sanctuaries for committing to dark sky friendly lighting practices. Two previous studies examined the extent to which designation results in reduced light emissions by comparing the upward radiance of designated International Dark Sky Communities (IDSCs) and communities inside International Dark Sky Reserves (IDSRs) to non-designated places using upward radiance satellite data. This study compared designated IDSCs and IDSR communities to non-designated communities using upward radiance satellite data as input for a sky brightness model and added additional requirements for determining non-designated places used for comparison. The study area was International Dark Sky Communities located in Central Texas and Greater Big Bend International Dark Sky Reserve communities located in West Texas. Visible Infrared Imaging Radiometer Suite Day-Night Band data was used as input for the National Park Service All Sky Light Pollution Ratio (ALR) sky brightness model to determine mean sky brightness from 2012-2022 to compare sky brightness trends. Of the designated communities in the study, 69% showed no difference in trends or a faster upward trend compared to their control community while 31% showed either no overall change or a slower trend in sky brightness compared to their control community. The Greater Big Bend IDSR communities overall showed a mix of slower upward trend or zero trend in sky brightness compared to Central Texas IDSCs. There was noticeable influence on sky brightness for communities located close to the Permian Basin Oil and Gas region of West Texas. Places in the study located closer to urban centers saw a faster increase in sky brightness over time than designated places located further away from major urban centers. Understanding sky brightness trends through GIS analysis revealed the geographic influences of sky brightness on designated places. Keywords: Light pollution; Night sky brightness; Skyglow.
light pollution, night sky brightness, skyglow
Jackson, A. P. (2023). Sky brightness in Texas: A Comparative Study between International Dark Sky Places and Control Communities (Unpublished thesis). Texas State University, San Marcos, Texas.