Table 3.

Seasonal model performance for MDA8 ozone at AQS sites as measured by normalized mean bias (NMB), normalized mean error (NME), and correlation coefficient for the BASE simulations for all sites and the five analysis regions is shown in Fig. 2. The metrics were computed at each AQS site for each season, and the median metric across all sites in a given region and season is shown in this table. The fonts used in the table are based on the model evaluation goals and acceptability criteria proposed by Emery et al. (2017). Cells in normal font indicate regions and seasons where model performance meets the goal for a given metric (NMB < 5 %, NME < 15 %, and R > 0.75), cells in italics indicate regions and seasons where model performance meets the acceptability criterion but ± not the goal (5 % < NMB < 15 %, 15 % < NME < 25 %, and 0.5 < R < 0.75), and cells in bold font indicate regions and seasons where neither the goal ± nor the acceptability ± criterion are met (NMB ≥ ±15 %, NME ≥ 25 %, and R ≤ 0.5).

		All	NW	IMW	MW	SE	NE
NMB	Spring	2.1	9.1	3.6	2.0	2.6	− 3.2
	Summer	6.8	13.5	− 3.2	6.3	9.6	2.6
	Fall	3.1	13.0	2.1	1.0	2.1	1.7
	Winter	−5.1	11.0	−2.8	−23.1	−7.3	−28.2
NME	Spring	11.3	13.1	8.5	11.3	11.3	12.0
	Summer	13.6	16.2	10.5	13.3	14.7	12.0
	Fall	13.5	20.8	9.4	12.1	11.7	14.4
	Winter	18.8	20.5	19.2	28.8	12.0	29.1
R	Spring	0.75	0.57	0.66	0.8	0.82	0.74
	Summer	0.73	0.78	0.67	0.7	0.72	0.82
	Fall	0.82	0.72	0.74	0.84	0.81	0.87
	Winter	0.65	0.57	0.6	0.75	0.76	0.69