Final answer:
Tropospheric ozone typically peaks during hot sunny days in urban settings and can affect both urban and rural areas. The substantial seasonal depletion of ozone, often referred to as the 'ozone hole', is most prominent over Antarctica from late August to early December. Efforts like the Montreal Protocol have resulted in a 20% improvement in ozone depletion since 2005.
Step-by-step explanation:
The tropospheric ozone usually peaks on hot sunny days in urban environments, although high levels can still be reached during colder months. The ozone in this layer can be transported by wind, affecting both urban and rural areas. In the upper atmosphere, ozone concentration fluctuates with the seasons, with substantial depletion known as the "ozone hole" occurring mainly over the Antarctic from late August through early December, reaching its largest size in the spring. This seasonal depletion is mainly due to chemicals like chlorofluorocarbons (CFCs) which break down the ozone molecules. Thanks to global initiatives such as the Montreal Protocol, ozone depletion has been reduced, with a 20% improvement since 2005.