At a typical urban site, the ground level ozone concentration would be maximum at what time of the day?

Question

Question

This question was previously asked in

UGC NET Paper 1: Held on 21st Oct 2022 Shift 1

Answer 1

Ground-level ozone produced just above the earth's surface is colourless, intensely irritating gas.

Key Points

It is created when two principal pollutants react in sunlight and still air.
Volatile organic compounds (VOCs) and nitrogen oxides (NOx) are these two main pollutants.
It is known as a secondary pollutant.
Its usual concentration is 20 to 30 parts per billion by volume.
Summertime temperatures and increased sunlight cause more ozone to accumulate.
In the summer, when direct sunlight is at its strongest, ozone levels are normally at their maximum in the afternoon.

Thus, at a typical urban site, the ground level ozone concentration would be maximum in the Afternoon.

Additional Information

Ground-level ozone in contrast to stratospheric ozone can be hazardous to human health.