University pollution issues

Low cloud may stop stargazing but it is very handy at showing up bad lighting practice. Here the University of Bath is photographed from two angles on the same evening and demonstrates the amount of light leaking from the campus. Taken at 6:30pm on a term time Monday, it is probably the lighting at the sports facilities causing this waste and light pollution.

The view, northwest to the campus from Bloomfield Road, above shows several interesting features. Looking to the upper left, the orange sky glow of sodium street lighting is visible caused by the rest of Bath. It has whitened over time following the local government replacement policy of sodium lights for white LEDs. The streetlamps on Bloomfield Road have been replaced with LEDs and you can clearly see they are downlighting about 30 deg below the horizontal across the road and about 60 deg below the horizon behind so they are not shining into the houses behind. Now looking at the campus on the top of the hill you can see the varying ages on the buildings/facilities by the light pollution; to the left is older and still uses some sodium, orange lighting and to the right are the new sports facilities. The interesting thing is both are leaking a large amount of light upwards.

The picture below is from Churchill bridge looking East over the top of the Station. You can see that the white light pollution is more extensive from this angle. The light path on the map shows you why… From Bloomfield you are looking end on to the Training Village but from town you are are looking on sideways on to the running track and facilities so the impact of poor lighting is broader. But also look at the orange at the top of the picture; that is glow from wasted light from the rest of the city.