Table 4.

Average (±standard deviation) of two mass concentration ratios often applied to distinguish local dust from non-local dust (i.e., Asian dust). Statistics are calculated for three extreme event categories: non-Asian dust, Asian dust, and both Other and CM simultaneously.

Site Name	PM10:PM2.5			Fe:Ca
	Non-Asian Dust	Asian Dust	Other and CM	Non-Asian Dust	Asian Dust	Other and CM
Chiricahua	0.32 ± 0.17	0.30 ± 0.10	0.19 ± 0.08	0.82 ± 0.35	0.88 ± 0.24	0.95 ± 0.30
Grand Canyon	0.38 ± 0.11	0.43 ± 0.11	0.34 ± 0.06	0.83 ± 0.27	0.79 ± 0.21	0.92 ± 0.19
Organ Pipe	0.27 ± 0.10	0.39 ± 0.08	0.20 ± 0.09	0.98 ± 0.35	0.81 ± 0.16	0.96 ± 0.43
Phoenix	0.35 ± 0.16	0.30 ± 0.08	0.20 ± 0.07	1.27 ± 0.28	1.02 ± 0.25	1.22 ± 0.26
Queen Valley	0.27 ± 0.17	0.30 ± 0.10	0.18 ± 0.05	1.04 ± 0.35	0.84 ± 0.13	1.09 ± 0.40
Saguaro NM	0.57 ± 0.36	0.39 ± 0.13	0.27 ± 0.04	0.79 ± 0.28	0.80 ± 0.15	0.89 ± 0.24
SaguaroWest	0.46 ± 0.26	0.31 ± 0.12	0.21 ± 0.06	0.95 ± 0.48	1.04 ± 0.38	1.02 ± 0.44
Tonto	0.35 ± 0.19	0.38 ± 0.14	0.23 ± 0.08	1.00 ± 0.31	0.86 ± 0.15	1.16 ± 0.38