Table 3. O₃ 2019 model performance statistics.

The Prophet model forecasted 2019 values on an hourly basis, which was compared to actual values over a 5 day, 15 day, 1 month, and 1 year period. Units for MSE, RMSE, and MAE are ppm. The MAE was on average 0.0113 ppm away from the actual value after 5 days and as the time increased away from the known values, the error increased; the total MAE increase from 5 to 365 days was 0.0021 ppm.

Time	MSE	RMSE	MAE	Coverage
5 Days	2.34 × 10−4	1.53 × 10−2	1.13 × 10−2	80.9%
15 Days	2.47 × 10−4	1.57 × 10−2	1.15 × 10−2	80.3%
1 Month	2.58 × 10−4	1.60 × 10−2	1.17 × 10−2	79.9%
6 Months	2.99 × 10−4	1.73 × 10−2	1.30 × 10−2	78.5%
1 Year	3.13 × 10−4	1.77 × 10−2	1.34 × 10−2	76.5%