|
Bridger Wilderness Area
Trends Analysis |
|
| The tables and figures below
show the trends analysis
results for 20% worst, middle 60% and 20% best days at BRID1 based on
light extinction coefficient
data from 1994 to 2003. No significant trend is observed for aerosol light
extinction coefficients in 20% worst days.
The nitrate extinction increased significantly in the worst days and in
middle 60% days. Significant decrease trend is found for aerosol
light extinction coefficients in 20% best days, which is caused mainly by
decrease in sulfate, nitrate, and CM light extinction. |
|
|
| Table 1. Number of valid
measurements used in the trends analysis |
|
|
Site |
Year |
StartDate |
EndDate |
NoMeas |
|
BRID1 |
1994 |
1/1/1994 |
12/31/1994 |
96 |
|
BRID1 |
1995 |
1/4/1995 |
12/23/1995 |
96 |
|
BRID1 |
1996 |
1/10/1996 |
12/28/1996 |
94 |
|
BRID1 |
1997 |
1/1/1997 |
12/27/1997 |
97 |
|
BRID1 |
1998 |
1/3/1998 |
12/30/1998 |
92 |
|
BRID1 |
1999 |
1/2/1999 |
12/29/1999 |
83 |
|
BRID1 |
2000 |
1/1/2000 |
12/29/2000 |
106 |
|
BRID1 |
2001 |
1/1/2001 |
12/30/2001 |
112 |
|
BRID1 |
2002 |
1/5/2002 |
12/31/2002 |
106 |
|
BRID1 |
2003 |
1/3/2003 |
12/29/2003 |
116 |
|
|
| 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) |
|
BRID1 |
1994 |
20.41 |
6.67 |
0.71 |
7.89 |
1.67 |
1.09 |
2.38 |
|
BRID1 |
1995 |
16.11 |
5.73 |
0.70 |
5.20 |
1.50 |
0.57 |
2.40 |
|
BRID1 |
1996 |
25.01 |
6.70 |
1.23 |
10.08 |
2.79 |
0.93 |
3.28 |
|
BRID1 |
1997 |
17.43 |
7.10 |
1.20 |
3.82 |
1.27 |
0.59 |
3.44 |
|
BRID1 |
1998 |
21.83 |
7.03 |
1.26 |
8.80 |
1.81 |
0.90 |
2.03 |
|
BRID1 |
1999 |
21.68 |
5.80 |
1.14 |
8.26 |
1.76 |
1.02 |
3.70 |
|
BRID1 |
2000 |
21.60 |
5.32 |
1.42 |
9.00 |
2.51 |
0.90 |
2.43 |
|
BRID1 |
2001 |
21.45 |
6.95 |
1.65 |
6.92 |
1.53 |
1.45 |
2.95 |
|
BRID1 |
2002 |
22.74 |
5.39 |
2.00 |
10.00 |
2.11 |
1.05 |
2.20 |
|
BRID1 |
2003 |
22.66 |
5.47 |
1.07 |
11.20 |
2.09 |
0.72 |
2.11 |
|
|
|
|
|
|
|
|
|
|
|
Slope (1/Mm/Year) |
|
0.255 |
-0.082 |
0.112 |
0.368 |
0.055 |
0.018 |
-0.029 |
|
S-Value |
|
13 |
-11 |
21 |
17 |
9 |
7 |
-5 |
|
P-Value |
|
0.146 |
0.190 |
0.036 |
0.078 |
0.242 |
0.300 |
0.364 |
|
 |
|
| 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) |
|
BRID1 |
1994 |
10.78 |
3.89 |
0.78 |
3.29 |
0.70 |
0.43 |
1.70 |
|
BRID1 |
1995 |
9.53 |
3.74 |
0.77 |
2.40 |
0.99 |
0.29 |
1.34 |
|
BRID1 |
1996 |
11.26 |
3.98 |
0.72 |
3.41 |
1.15 |
0.46 |
1.54 |
|
BRID1 |
1997 |
9.69 |
3.76 |
0.74 |
2.47 |
0.75 |
0.25 |
1.70 |
|
BRID1 |
1998 |
12.22 |
4.48 |
0.75 |
4.02 |
1.02 |
0.35 |
1.59 |
|
BRID1 |
1999 |
11.81 |
3.66 |
0.82 |
3.79 |
1.09 |
0.49 |
1.97 |
|
BRID1 |
2000 |
10.01 |
3.98 |
0.99 |
2.95 |
0.89 |
0.29 |
0.91 |
|
BRID1 |
2001 |
10.57 |
4.31 |
1.09 |
2.66 |
0.94 |
0.47 |
1.10 |
|
BRID1 |
2002 |
9.94 |
3.63 |
1.37 |
2.47 |
1.03 |
0.45 |
0.99 |
|
BRID1 |
2003 |
9.36 |
3.22 |
|
