Table 4.

Long-term trend analysis for the Southwest monsoon season (JAS). Slopes of each parameter versus year are shown with correlation coefficients (r²) of the linear best fit line in parenthesis. Units are μg m^–3 yr^–1 for the aerosol species, mg L^–1 yr^–1 for the rain species, and yr^–1 for the coarse: fine ratio, ${\mathrm{NO}}_3^{-}$ : ${\mathrm{SO}}_4^{2-}$ ratio, and pH. No other common aerosol and rain water species are shown as they do not have statistically significant changes over the durations shown in Table 1.

	Bandelier	Bryce Canyon	Chiricahua	Gila Cliff	Mesa Verde	Organ Pipe
Particulate SO4	–0.037 (0.56)	–0.029 (0.71)	–0.038 (0.52)	–0.047 (0.72)	–0.042 (0.78)	–0.109 (0.80)
Particulate NO3			–0.006 (0.43)			–0.016 (0.44)
Particulate NO3 : SO4					0.005 (0.26)
Particulate Coarse : Fine						0.084 (0.30)
Rain SO4		–0.062 (0.28)		–0.057 (0.53)
Rain NO3
Rain NO3 : SO4	0.037 (0.33)	0.049 (0.26)		0.065 (0.52)	0.080 (0.81)
Rain pH	0.028 (0.42)	0.051 (0.32)	0.026 (0.38)	0.034 (0.43)