Heatwave Smog: Ground-Level Ozone Formation

Ground-level ozone is the main ingredient of summer smog, and it is manufactured in the air itself when nitrogen oxides from traffic meet volatile organic compounds in sunlight. This simulator renders that photochemistry as a live 3D reaction: orange NOx and yellow-green VOC molecules drift through a modelled air parcel and, when they meet under UV light, snap together into blue ozone. Temperature drives three real heat-health mechanisms at once — an Arrhenius-style reaction-rate increase, doubling biogenic VOC emission from vegetation, and faster thermal decomposition of the PAN reservoir that otherwise locks NOx away — so cranking up the heat on a sunny, high-traffic day reproduces exactly the heatwave-smog spike that climate-health researchers warn about. Live readouts track ozone concentration in ppb against real US EPA air-quality bands, the instantaneous reaction rate, and the size of the PAN reservoir.