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San Gorgonio Wilderness Area Trends Analysis
The tables and figures below show the trends analysis results for 20% worst, middle 60% and 20% best days at SAGO1 based on light extinction coefficient data from 1994 to 2003. A significant increase trend is found for total aerosol light extinction in 20% worst days caused by significant increase in nitrate extinction. But significant decrease trends in sulfate, LAC and soil light extinction coefficients are found in 20% worst days. Significant decrease in total aerosol light extinction coefficients are found in both middle 60% and 20% best days.

Table 1. Number of valid measurements used in the trends analysis
Site Year StartDate EndDate NoMeas
SAGO1 1994 1/1/1994 12/17/1994 73
SAGO1 1995 1/11/1995 12/23/1995 92
SAGO1 1996 1/3/1996 12/21/1996 78
SAGO1 1997 2/1/1997 12/27/1997 73
SAGO1 1998 1/3/1998 12/19/1998 55
SAGO1 1999 1/6/1999 12/29/1999 86
SAGO1 2000 1/1/2000 12/26/2000 84
SAGO1 2001 1/7/2001 12/30/2001 106
SAGO1 2002 1/5/2002 12/31/2002 111
SAGO1 2003 1/3/2003 12/29/2003 113
Table 2. Trends analysis for 20% worst visibility days
Site Year Bep (1/Mm) Sulfate_Ext (1/Mm) Nitrate_Ext (1/Mm) OMC_Ext (1/Mm) LAC_Ext (1/Mm) Soil_Ext (1/Mm) CM_Ext (1/Mm)
SAGO1 1994 65.52 18.17 15.39 17.06 6.50 1.21 7.20
SAGO1 1995 57.18 15.92 15.25 11.60 5.79 1.33 7.28
SAGO1 1996 68.45 16.93 20.61 17.03 6.79 1.20 5.89
SAGO1 1997 75.74 15.05 30.81 16.60 6.50 1.25 5.54
SAGO1 1998 68.33 14.48 31.90 11.31 6.19 1.06 3.40
SAGO1 1999 76.45 14.34 39.98 10.98 5.49 0.98 4.69
SAGO1 2000 75.14 12.17 38.19 11.31 5.96 1.20 6.31
SAGO1 2001 70.65 13.87 33.46 11.13 4.77 1.20 6.21
SAGO1 2002 83.62 12.27 48.09 12.14 4.76 1.04 5.33
SAGO1 2003 81.39 15.46 39.23 15.13 4.26 0.95 6.37
               
Slope (1/Mm/Year)   2.086 -0.550 3.147 -0.156 -0.256 -0.028 -0.095
S-Value   27 -27 33 -15 -33 -27 -7
P-Value   0.008 0.008 0.001 0.108 0.001 0.008 0.300

Table 3. Trends analysis for middle 60% visibility days
Site Year Bep (1/Mm) Sulfate_Ext (1/Mm) Nitrate_Ext (1/Mm) OMC_Ext (1/Mm) LAC_Ext (1/Mm) Soil_Ext (1/Mm) CM_Ext (1/Mm)
SAGO1 1994 40.67 8.28 16.44 7.95 3.69 0.48 3.83
SAGO1 1995 38.97 8.15 15.64 6.36 3.76 0.80 4.27
SAGO1 1996 36.75 7.23 16.98 5.09 2.72 0.83 3.90
SAGO1 1997 40.30 9.98 11.52 8.96 3.95 1.07 4.82
SAGO1 1998 37.04 7.91 14.82 7.22 3.44 0.69 2.97
SAGO1 1999 36.34 7.76 13.19 7.58 3.37 0.89 3.56
SAGO1 2000 34.98 6.69 14.31 6.48 3.23 0.69 3.59
SAGO1 2001 36.78 8.98 13.72 6.50 3.14 0.80 3.64
SAGO1 2002 38.02 7.76 15.20 7.16 2.88 1.09 3.93
SAGO1 2003 34.31 7.42 13.38 6.77 2.72 0.64 3.38
               
Slope (1/Mm/Year)   -0.547 -0.092 -0.286 -0.074 -0.108 0.017 -0.050
S-Value   -23 -15 -15 -3 -25 5 -9
P-Value   0.023 0.108 0.108 0.431 0.014 0.364 0.242

Table 4. Trends analysis for 20% best visibility days
Site Year Bep (1/Mm) Sulfate_Ext (1/Mm) Nitrate_Ext (1/Mm) OMC_Ext (1/Mm) LAC_Ext (1/Mm) Soil_Ext (1/Mm) CM_Ext (1/Mm)
SAGO1 1994 24.14 1.50 18.00 1.52 1.39 0.21 1.50
SAGO1 1995 25.02 1.70 18.48 1.79 1.31 0.26 1.49
SAGO1 1996 16.09 2.84 4.54 3.45 1.90 0.64 2.72
SAGO1 1997 11.04 2.56 1.61 2.79 1.32 0.37 2.39
SAGO1 1998 11.32 2.42 2.66 3.31 1.33 0.36 1.24
SAGO1 1999 12.68 1.92 2.41 3.55 1.79 0.65 2.36
SAGO1 2000 11.84 2.65 2.87 2.66 1.77 0.30 1.59
SAGO1 2001 8.19 2.09 2.53 1.61 1.24 0.15 0.58
SAGO1 2002 9.41 2.45 2.89 1.77 1.17 0.22 0.91
SAGO1 2003 7.00 1.76 1.83 1.47 0.92 0.21 0.81
               
Slope (1/Mm/Year)   -1.580 0.010 -0.387 -0.046 -0.030 -0.011 -0.098
S-Value   -31 3 -17 -9 -19 -11 -21
P-Value   0.002 0.431 0.078 0.242 0.054 0.190 0.036

Page last updated 30 March 2005