Summer is the “ozone season.” Ozone (O3) typically reaches high levels in summer since O3 formation is dependent on the intensity of sunlight. As summer progresses, O3-induced symptoms become more obvious due to continued exposure to O3. Sunlight initiates the chemical reactions with nitrogen oxides (NOx) and volatile organic compounds (VOCs) to form O3.
Photo records of ozone injury in NASA GSFC’s O3 bioindicator garden are available on the garden’s Flickr page.
NASA GSFC 2018 Ozone Season