MAS October Monthly Meeting

Modeling Global Light Pollution

David Lorenz, October 2021 MAS Speaker4

In this talk, I discuss my light pollution atlas, light pollution modeling, and recent trends in light pollution across the world. A light pollution atlas (artificial night sky brightness) is distinct from the maps that show the lights as they would appear from orbit in space looking down. These space-view maps are the input data to a model of the propagation, extinction, and scattering of light in the atmosphere. The output of the model is the estimated artificial light pollution at zenith. I will also use the light pollution model to understand 1) the role of atmospheric aerosols (fine solid particles or liquid droplets suspended in the air) on light pollution and 2) the role of the direction of light propagation from light sources on light pollution (nearly horizontal light beams are the most harmful).

David Lorenz is an amateur astronomer with a professional background in the atmospheric sciences. His favorite astronomical target is the milky way from dark skies with naked-eye and binoculars. In the past, when seeking out dark skies, he relied heavily on the original global light pollution atlas created by Cinzano et al in 2001. Later on, when he grew impatient with the lack of updates to the atlas, he decided to repeat the calculations of Cinzano on more recent satellite data. He has continued to update the atlas through the present. He currently works at the Center for Climatic Research at the University of Wisconsin-Madison.

Due to the accelerating infection and hospitalization rate due to COVID-19 Delta, MAS HAS MADE THE DECISION TO STAY VIRTUAL FOR OUR OCTOBER MEETING. The October meeting will be hosted with Zoom as before. MEMBERS WILL RECEIVE AN EMAIL WITH LINKS AND INSTRUCTIONS a day or so before the event. Again this month we are opening the virtual meeting up to our web followers who may want to join in. If you would like to attend the MAS virtual meeting, send an email to by noon Friday, Oct. 8 to let us know of your interest. We will email you the instructions and link by 3pm that day which will get you into the meeting by 7:30 on Friday evening.