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Mesa Verde National Park Trends Analysis
The tables and figures below show the trends analysis results for 20% worst, middle 60% and 20% best days at MEVE1 based on light extinction coefficient data from 1994 to 2003. Overall, there are significant increase trends in nitrate, soil and total aerosol light extinctions, and there is a significant decrease trend in sulfate extinctions in 20% worst days. Nitrate also increased significantly in both middle 60% and 20% best days. No significant trends are found for total aerosol light extinctions in middle 60% days, and 20% best days. 

Table 1. Number of valid measurements used in the trends analysis
Site Year StartDate EndDate NoMeas
MEVE1 1994 1/1/1994 12/31/1994 97
MEVE1 1995 1/4/1995 12/30/1995 95
MEVE1 1996 1/3/1996 12/21/1996 76
MEVE1 1997 1/4/1997 12/31/1997 78
MEVE1 1998 1/3/1998 12/26/1998 92
MEVE1 1999 1/2/1999 12/29/1999 96
MEVE1 2000 1/1/2000 12/29/2000 95
MEVE1 2001 1/1/2001 12/30/2001 107
MEVE1 2002 1/5/2002 12/28/2002 100
MEVE1 2003 1/3/2003 12/23/2003 106
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)
MEVE1 1994 23.21 9.47 0.86 5.66 1.51 1.12 4.58
MEVE1 1995 23.78 12.52 0.89 4.49 1.88 0.81 3.19
MEVE1 1996 24.11 8.09 0.83 7.33 2.73 2.39 2.73
MEVE1 1997 21.69 10.06 1.06 4.05 1.47 1.23 3.82
MEVE1 1998 24.90 11.51 1.18 6.44 2.17 1.15 2.44
MEVE1 1999 31.49 8.68 1.33 6.15 2.34 2.95 10.04
MEVE1 2000 31.61 8.14 1.89 12.53 3.73 1.73 3.59
MEVE1 2001 20.97 8.59 2.04 4.01 1.29 1.65 3.39
MEVE1 2002 34.66 6.27 3.69 9.36 2.24 3.93 9.16
MEVE1 2003 45.15 6.86 2.60 16.24 3.38 3.73 12.35
               
Slope (1/Mm/Year)   1.566 -0.456 0.227 0.729 0.154 0.194 0.572
S-Value   25 -23 39 15 13 25 13
P-Value   0.014 0.023 0.000 0.108 0.146 0.014 0.146

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)
MEVE1 1994 15.22 6.41 0.89 3.31 1.18 0.65 2.78
MEVE1 1995 12.65 5.29 0.88 2.72 1.43 0.60 1.75
MEVE1 1996 12.32 4.43 0.77 2.88 1.64 1.06 1.54
MEVE1 1997 13.75 6.47 0.94 2.74 1.57 0.54 1.50
MEVE1 1998 14.84 6.11 0.88 4.01 1.65 0.56 1.63
MEVE1 1999 13.04 4.68 0.82 3.74 1.49 0.63 1.69
MEVE1 2000 13.06 4.73 1.28 3.98 1.11 0.67 1.30
MEVE1 2001 13.71 5.99 1.24 2.93 1.04 0.89 1.62
MEVE1 2002 15.22 4.84 1.85 3.48 1.15 1.16 2.73
MEVE1 2003 15.14 4.65 1.63 3.86 1.05 1.04 2.92
               
Slope (1/Mm/Year)   0.176 -0.080 0.094 0.085 -0.050 0.044 0.016
S-Value   11 -13 21 15 -17 19 3
P-Value   0.190 0.146 0.036 0.108 0.078 0.054 0.431

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)
MEVE1 1994 9.19 3.97 0.90 1.94 0.80 0.38 1.21
MEVE1 1995 6.73 2.29 0.92 1.34 1.02 0.34 0.83
MEVE1 1996 6.97 2.82 1.00 1.32 0.94 0.32 0.57
MEVE1 1997 7.60 3.10 0.45 1.73 0.98 0.36 0.98
MEVE1 1998 8.37 2.97 0.56 2.28 1.12 0.37 1.07
MEVE1 1999 7.47 2.71 0.61 1.86 1.06 0.35 0.88
MEVE1 2000 6.95 2.62 0.80 1.93 0.80 0.23 0.57
MEVE1 2001 6.59 3.12 0.75 1.04 0.46 0.35 0.86
MEVE1 2002 7.69 2.92 1.10 1.34 0.66 0.60 1.07
MEVE1 2003 7.63 2.36 0.98 2.05 0.74 0.50 1.01
               
Slope (1/Mm/Year)   -0.025 -0.066 0.025 0.004 -0.036 0.008 0.000
S-Value   -3 -9 9 3 -13 9 1
P-Value   0.431 0.242 0.242 0.431 0.146 0.242 0.500

Page last updated 30 March 2005