8.3.9 (HL)—Smog intensification factors

Sunlight speeds smog chemistry, while weak wind, temperature inversion, mountains or high buildings keep precursors and products concentrated near the ground.

Separate creation from accumulation: weather and topography do not create emissions, but they change reaction time and dispersion. A warm layer above cool polluted air is an inversion.

In a basin with weak wind, NOx and VOCs remain near the surface long enough for sunlight to form more ozone.

No. Check precursor emissions and mixing/dispersion as well as sunlight.

A trapping condition intensifies smog; it does not replace the need for precursor gases.