Skip to main content

View full-text article in PMC

. Author manuscript; available in PMC: 2020 Jul 1.

Published in final edited form as: Environ Int. 2019 May 8;128:310–323. doi: 10.1016/j.envint.2019.04.057

Table 1.

Summary of NO₂ and NO_x measurements for the training and test samples

Source	#Monitoring locations	Distribution of monitoring locations (number of biweekly periods with valid data)				Mean concentration (ppb)		Standard deviation (ppb)		Correlation between NO₂ and NO_x
Source	#Monitoring locations	≤100	(100,280]	(280,400]	>400	NO₂	NO_x	NO₂	NO_x	Correlation between NO₂ and NO_x
Southern California AQS^a	113	21	31	17	44	24.5	46.8	11.9	31.7	0.82
Southern California Non-AQS	1320	1320				17.2	37.6	9.2	23.5	0.85
Southern California Total	1433	1341	13	17	44	23.4	45.4	11.7	31.2	0.82
Northern California AQS	78	24	16	8	30	13.4	23.5	6.45	18.1	0.89
California Total	1511	1365	29	25	74	16.0	28.8	10.3	27.4	0.87

Note:

^a.

AQS: EPA’s Air Quality System archive of quality-assured routinely collected measurement data.