(BRAVO) Study: Final Report. - Desert Research Institute

Final Report — September 2004
Figure 12-6 contains the five individual year plots that are summarized in Figure
12-5. Particulate components that contribute to Big Bend haze have large interannual
variations in magnitude and timing, as shown in these plots. The broadness of the multi-year
averaged springtime peak of carbonaceous/sulfate/coarse particle haze in Figure 12-5 is in
fact a composite of different patterns, some with narrow peaks (e.g., 1998, a year of
unusually heavy smoke impacts), others with broader periods with some combination of
elevated carbonaceous or sulfate or coarse particulate concentrations. Similar interannual
variations are also evident in the summer and fall periods when elevated particulate sulfate
contributes to haze episodes.
Extinction (Mm -1 )
110
100
90
80
70
60
50
40
30
20
10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Rayleigh Sulfate Nitrate Organics LAC Soil Coarse Mass
1998
Extinction (Mm -1 )
110
100
90
80
70
60
50
40
30
20
10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Rayleigh Sulfate Nitrate Organics LAC Soil Coarse Mass
1999
110
100
90
80
110
100
90
80
Extinction (Mm -1 )
70
60
50
40
Extinction (Mm -1 )
70
60
50
40
30
30
20
20
10
10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Rayleigh Sulfate Nitrate Organics LAC Soil Coarse Mass
2000
Rayleigh Sulfate Nitrate Organics LAC Soil Coarse Mass
2001
110
100
90
80
Extinction (Mm -1 )
70
60
50
40
30
20
10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 12-6. Big Bend extinction budget time
plots for individual years. These time plots were
smoothed using a 15-day moving averages.
Rayleigh Sulfate Nitrate Organics LAC Soil Coarse Mass
2002
12-16