Mountains can further trap smog. Temperature inversion. can cause high concentrations of pollutants. Atmospheric brown cloud. a new type of pollution. Atmospheric brown cloud. has a high proportionof black carbon and soot. dimming over large cities, less rainfall, heating of air, decreased reflection of snow and ice.
Smog test time is as good a time as any to do right by your car. By the time you’re done, you’ll feel like you’ve got a new car again. This page is particularly geared to the California biannual smog check.