Table 1.

Performance Metrics for Annual and Seasonal Accumulated WRF Precipitation Predictions and CMAQv5.0.2 Wet Deposition Predictions for Sulfate, Nitrate, and Ammonium Including Observation Mean (MEAN OBS), Model Mean (MEAN MOD), Mean Bias (MB), Normalized Mean Bias (NMB), Root‐Mean‐Square Error (RMSE), Mean Error (ME), Normalized Mean Error (NME), and Pearson Correlation Squared (R²)

Seasons	Variables	N	MEAN OBS	MEAN MOD	MB	NMB (%)	RMSE	ME	NME (%)	R 2
	Precipitation	1,964	94.41	99.4	4.99	5.3	26.81	19.82	21.9	0.67
	NO3 −	1,964	7.53	7.43	−0.09	−1.2	2.19	1.60	21.2	0.76
Annual	NH4 +	1,964	2.46	2.19	−0.27	−11.0	0.94	0.68	27.6	0.60
	SO4 2−	1,964	8.87	8.47	−0.40	−4.5	2.76	1.92	21.7	0.81
	Precipitation	1,631	20.94	22.37	1.43	6.8	9.69	7.02	33.5	0.65
	NO3 −	1,631	1.45	1.58	0.13	8.6	0.77	0.55	37.8	0.58
Winter	NH4 +	1,631	0.32	0.24	−0.07	−23.4	0.20	.012	37.9	0.46
	SO4 2−	1,631	1.51	1.23	−0.28	−18.6	0.85	0.57	37.4	0.57
	Precipitation	1,801	24.35	29.06	2.71	11.1	9.61	6.99	28.7	0.61
	NO3 −	1,801	2.20	2.02	−0.18	−8.2	0.77	0.57	26.0	0.73
Spring	NH4 +	1,801	0.85	0.63	−0.22	−26.2	0.46	0.31	36.9	0.55
	SO4 2−	1,801	2.63	2.53	−0.10	−3.7	1.09	0.74	28.3	0.71
	Precipitation	1,802	27.24	29.15	1.91	7.0	13.35	9.34	34.3	0.47
	NO3 −	1,802	2.59	2.42	−0.17	−6.7	1.04	0.77	29.7	0.54
Summer	NH4 +	1,802	0.87	0.98	0.11	12.6	0.49	0.36	41.3	0.41
	SO4 2−	1,802	3.14	3.20	0.06	2.0	1.51	0.99	31.5	0.69
	precipitation	1,853	23.77	22.11	−1.65	−7.0	8.87	6.38	26.9	0.64
	NO3 −	1,853	1.44	1.62	0.18	12.4	0.71	0.48	33.5	0.65
Fall	NH4 +	1,853	0.46	0.39	−0.07	−14.9	0.25	0.17	36.5	0.50
	SO4 2−	1,853	1.83	1.73	−0.10	−5.4	0.79	0.54	29.6	0.69

Note. The definition of the evaluation metrics can be found in the supporting information. Statistics are based on the modeled and observed data from 183 NADP/NTN sites. Note that not all 183 sites have a valid observation for every season of every year (i.e., N < 183 sites×11 years). Modeled and observed values were paired in space by matching the observations to the model values from the grid cell that contains the monitor. The units are centimeter for precipitation, and kilogram/hectare for wet deposition. WRF = Weather Research and Forecasting; cmaq = Community Multiscale Air Quality Model.