The line chart illustrates how ozone layer concentration in the air changed daily from 6:00 to 24:00 over four separate years, specifically from 2019 to 2022, measured in Dobson Units (DU).
Overall, a clear daily pattern emerges where ozone levels consistently rose in the morning before falling steadily throughout the afternoon and evening across all years. Notably, 2022 generally recorded the highest concentrations, while 2020 tended to show the lowest.
From 6:00, ozone levels experienced a noticeable increase until midday. In 2019, the concentration started at 320 DU and peaked at 360 DU by 12:00. This upward trend was similar for other years; for example, 2022 began at 330 DU and reached its highest point of 370 DU at noon, marking the highest peak observed on the chart. In contrast, 2020 had the lowest starting point at 315 DU and peaked at 355 DU.
Following the midday peak, concentrations began to decline. By 15:00, all years showed a slight drop, with 2022 at 360 DU and 2019 at 350 DU. This downward trajectory continued, and by 24:00, ozone levels had fallen significantly. For instance, 2019 ended at 300 DU, while 2022 finished slightly higher at 310 DU. The lowest closing concentration was observed in 2020, which dropped to 295 DU.