Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-129 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15k. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site James River Face.
The ranges in PM2.5 for Categories 3 and 4 are 20-25 and ≥ 25 μ gm-3. Class 3 Class 4 Bin 23 Bin 14 Bin 16 Visibility Parameters Yesterday's FM at Richmond (μg/m 3 ) 27.9 21.7 22.6 Yesterday's FM at Greensboro-Winston-Salem (μg/m 3 ) 27.7 19.8 25.2 Yesterday's FM at Knoxville (μg/m 3 ) 26.8 23.7 33.3 Surface Meteorological Parameters Max. surface temperature (°C) 30.8 26.7 29.0 Min. surface temperature (°C) 17.6 18.9 13.2 Relative humidity (%) 72.8 83.8 69.4 Surface wind speed (ms -1 ) 2.0 0.6 0.8 Surface wind direction (degrees) 211 n/a 211 Persistence 0.9 0.8 0.9 Sea level pressure (mb) 1020 1023 1022 Rainfall (inches) 0.1 0.1 0.0 Rain (# periods) 0.8 1.0 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 16.3 14.3 13.9 Temperature PM 850 mb (°C) 16.6 16.0 15.4 Stability at Roanoke (°C) 3.8 0.1 4.9 Geopotential height difference 700 mb at Roanoke (m) -22.4 25.4 -1.8 Wind speed yesterday 700 mb at Dulles (ms -1 ) 7.9 6.3 4.9 Wind speed yesterday 700 mb at Roanoke (ms -1 ) 5.6 6.2 4.9 Wind direction yesterday 700 mb at Dulles (degrees) 278 270 352 Wind direction yesterday 700 mb at Roanoke (degrees) 307 225 315 Wind speed yesterday 850 mb at Dulles (ms -1 ) 5.3 3.3 4.2 Wind speed yesterday 850 mb at Roanoke (ms -1 ) 3.1 4.4 2.7 Wind speed AM 850 mb at Dulles (ms -1 ) 6.7 4.0 3.9 Wind speed AM 850 mb at Roanoke (ms -1 ) 9.5 4.9 5.7 Wind speed PM 850 mb at Dulles (ms -1 ) 9.0 4.9 5.1 Wind speed PM 850 mb at Roanoke (ms -1 ) 9.1 6.2 3.5 Wind direction yesterday 850 mb at Dulles (degrees) 278 252 259 Wind direction yesterday 850 mb at Roanoke (degrees) 239 45 315 Wind direction AM 850 mb at Dulles (degrees) 262 180 292 Wind direction AM 850 mb at Roanoke (degrees) 262 180 284 Wind direction PM 850 mb at Dulles (degrees) 243 198 270 Wind direction PM 850 mb at Roanoke (degrees) 225 135 304 Recirculation at Roanoke 0.0 0.3 0.3 Cloud average 1.9 2.3 2.0Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-130 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15l. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Linville Gorge.
The ranges in PM2.5 for Categories 3 and 4 are 17.5-20 and ≥ 20 μ gm-3.

Class 3 Class 4 Bin 30 Bin 19 Bin 25 Visibility Parameters Yesterday's FM at Knoxville (μg/m 3 ) 30.2 32.1 35.9 Yesterday's FM at Charlotte (μg/m 3 ) 26.4 15.7 30.0 Yesterday's FM at Greensboro-Winston-Salem (μg/m 3 ) 29.9 17.0 28.0 Surface Meteorological Parameters Max. surface temperature (°C) 18.4 18.8 23.3 Min. surface temperature (°C) 29.0 29.3 28.3 Relative humidity (%) 19.6 16.9 16.4 Surface wind speed (ms -1 ) 77.2 65.5 68.8 Surface wind direction (degrees) 0.8 1.4 0.8 Persistence 326 297 284 Sea level pressure (mb) 0.6 0.7 0.7 Rainfall (inches) 1018 1017 1021 Rain (# periods) 0.1 0.0 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 16.6 15.8 14.7 Temperature PM 850 mb (°C) 17.2 17.3 15.9 Stability at Greensboro (°C) -0.2 2.9 1.1 Geopotential height difference 700 mb at Greensboro (m) -12.3 -0.1 4.3 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 6 6 6 Wind direction yesterday 700 mb at Greensboro (degrees) 270 326 342 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 4 6 5 Wind speed AM 850 mb at Greensboro (ms -1 ) 5.8 6.4 5.0 Wind speed PM 850 mb at Greensboro (ms -1 ) 5.8 4.7 5.1 Wind direction yesterday 850 mb at Greensboro (degrees) 225 0 338 Wind direction AM 850 mb at Greensboro (degrees) 342 288 315 Wind direction PM 850 mb at Greensboro (degrees) 270 270 297 Recirculation at Greensboro 0.0 0.2 0.1 Cloud average 1.8 1.2 1.9Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-131 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15m. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Mammoth Cave.
The ranges in PM2.5 for Categories 3 and 4 are 20-25 and ≥ 25 μ gm-3.

Class 3 Class 4 Bin 30 Bin 5 Bin 24 Bin 21 Visibility Parameters Yesterday's FM at Nashville (μg/m 3 ) 26.2 10.0 22.1 30.4 Yesterday's FM at Knoxville (μg/m 3 ) 30.4 16.1 36.4 30.9 Yesterday's FM at Louisville (μg/m 3 ) 33.1 18.5 28.2 34.8 Surface Meteorological Parameters Max. surface temperature (°C) 31.3 28.8 28.9 30.8 Min. surface temperature (°C) 21.2 19.0 19.2 17.2 Relative humidity (%) 72.8 77.7 81.6 69.7 Surface wind speed (ms -1 ) 2.7 0.8 0.8 1.0 Surface wind direction (degrees) 236 n/a 108 252 Persistence 0.8 0.6 0.6 0.7 Sea level pressure (mb) 1018 1018 1016 1021 Rainfall (inches) 0.4 0.0 0.5 0.0 Rain (# periods) 1.4 0.0 0.8 0.3 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.2 14.7 16.4 15.9 Temperature PM 850 mb (°C) 18.5 17.7 17.3 16.8 Stability at Nashville (°C) -0.3 -1.0 0.2 1.7 Geopotential height difference 700 mb at Nashville (m) -10.5 22.7 1.3 -0.7 Wind speed yesterday 700 mb at Nashville (ms -1 ) 7.2 8.9 8.3 4.2 Wind direction yesterday 700 mb at Nashville (degrees) 297 315 315 90 Wind speed yesterday 850 mb at Nashville (ms -1 ) 4.7 6.3 2.8 3.5 Wind speed AM 850 mb at Nashville (ms -1 ) 8.0 4.9 3.8 4.6 Wind speed PM 850 mb at Nashville (ms -1 ) 6.6 3.5 4.6 4.5 Wind direction yesterday 850 mb at Nashville (degrees) 239 288 135 297 Wind direction AM 850 mb at Nashville (degrees) 270 315 225 297 Wind direction PM 850 mb at Nashville (degrees) 225 270 315 180 Recirculation at Nashville 0.0 0.3 0.5 0.3 Cloud average 1.8 1.8 2.0 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-132 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15n. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Mingo.
The ranges in PM2.5 for Categories 3 and 4 are 20-25 and ≥ 25 μ gm-3.

Class 3 Class 4
Bin 21 Bin 18 Bin 8 Visibility Parameters Yesterday's FM at St. Louis (μg/m 3 ) 33.2 25.8 17.5 Surface Meteorological Parameters Max. surface temperature (°C) 24.7 26.6 27.4 Min. surface temperature (°C) 9.6 14.8 10.8 Relative humidity (%) 69.6 73.6 64.6 Surface wind speed (ms -1 ) 0.8 1.3 2.1 Surface wind direction (degrees) 256 162 214 Persistence 0.8 0.8 0.9 Sea level pressure (mb) 1025 1018 1022 Rainfall (inches) 0.2 0.8 0.0 Rain (# periods) 0.0 0.1 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 10.9 14.0 14.2 Temperature PM 850 mb (°C) 11.1 15.1 15.3 Stability at Little Rock (°C) -1.2 -1.9 0.7 Geopotential height difference 700 mb at Little Rock (m) -7.4 -0.8 -6.4 Wind speed yesterday 700 mb at Springfield (ms -1 ) 7.4 11.6 7.0 Wind speed yesterday 700 mb at Little Rock (ms -1 ) 5.3 9.9 3.4 Wind speed yesterday 700 mb at Lincoln (ms -1 ) 9.7 10.0 10.1 Wind speed yesterday 700 mb at Nashville (ms -1 ) 3.4 6.8 6.7 Wind direction yesterday 700 mb at Springfield (degrees) 236 243 256 Wind direction yesterday 700 mb at Little Rock (degrees) 214 297 270 Wind direction yesterday 700 mb at Lincoln (degrees) 256 301 256 Wind direction yesterday 700 mb at Nashville (degrees) 90 252 270 Wind speed yesterday 850 mb at Springfield (ms -1 ) 6.7 9.0 8.2 Wind speed yesterday 850 mb at Little Rock (ms -1 ) 3.4 6.8 4.3 Wind speed yesterday 850 mb at Lincoln (ms -1 ) 7.7 8.5 7.1 Wind speed yesterday 850 mb at Nashville (ms -1 ) 4.7 4.6 5.1 Wind speed AM 850 mb at Springfield (ms -1 ) 5.4 5.5 8.6 Wind speed AM 850 mb at Little Rock (ms -1 ) 6.7 6.9 4.9 Wind speed AM 850 mb at Lincoln (ms -1 ) 8.0 7.7 7.8 Wind speed AM 850 mb at Nashville (ms -1 ) 5.8 7.1 6.7 Wind speed PM 850 mb at Springfield (ms -1 ) 6.3 4.6 15.1 Wind speed PM 850 mb at Little Rock (ms -1 ) 5.2 5.9 8.8 Wind speed PM 850 mb at Lincoln (ms -1 ) 8.1 4.9 14.2 Wind speed PM 850 mb at Nashville (ms -1 ) 5.9 5.1 6.5 Wind direction yesterday 850 mb at Springfield (degrees) 194 202 180 Wind direction yesterday 850 mb at Little Rock (degrees) 194 207 166 Wind direction yesterday 850 mb at Lincoln (degrees) 236 252 270Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-133 VISTAS Meteorological Characterization

06-046 December 8, 2006 Class 3 Class 4 Bin 21 Bin 18 Bin 8 Wind direction yesterday 850 mb at Nashville (degrees) 207 225 180 Wind direction AM 850 mb at Springfield (degrees) 225 279 236 Wind direction AM 850 mb at Little Rock (degrees) 225 236 214 Wind direction AM 850 mb at Lincoln (degrees) 256 281 236 Wind direction AM 850 mb at Nashville (degrees) 225 252 297 Wind direction PM 850 mb at Springfield (degrees) 194 153 194 Wind direction PM 850 mb at Little Rock (degrees) 214 191 194 Wind direction PM 850 mb at Lincoln (degrees) 225 270 225 Wind direction PM 850 mb at Nashville (degrees) 243 360 194 Cloud average 2.0 1.6 1.4Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-134 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15o. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for Okefenokee.

The ranges in PM2.5 for Categories 3 and 4 are 15-20 and ≥ 20 μ gm-3.

Class 3 Class 4 Bin 28 Bin 31 Bin 3 Bin 30 Visibility Parameters Yesterday's FM at Jacksonville (μg/m 3 ) 18.3 30.2 9.5 30.2 Surface Meteorological Parameters Max. surface temperature (°C) 31.0 27.1 30.8 32.7 Min. surface temperature (°C) 19.3 15.6 17.5 21.6 Relative humidity (%) 71.9 75.9 71.4 74.1 Surface wind speed (ms -1 ) 2.0 2.6 2.1 1.5 Surface wind direction (degrees) n/a 117 108 153 Persistence 0.7 0.8 0.8 0.6 Sea level pressure (mb) 1016 1022 1020 1016 Rainfall (inches) 0.1 0.0 0.0 0.0 Rain (# periods) 0.6 0.4 0.3 0.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.9 12.7 15.1 17.5 Temperature PM 850 mb (°C) 16.6 13.0 16.1 18.1 Stability at Jacksonville (°C) 0.3 -0.5 1.5 -0.4 Geopotential height difference 700 mb at Jacksonville (m) -3.9 -4.8 2.5 -1.8 Wind speed yesterday 700 mb at Jacksonville (ms -1 ) 8.5 7.5 5.9 8.6 Wind speed yesterday 700 mb at Tallahassee (ms -1 ) 6.9 6.2 6.2 6.7 Wind direction yesterday 700 mb at Jacksonville (degrees) 304 270 315 342 Wind direction yesterday 700 mb at Tallahassee (degrees) 315 360 315 346 Wind speed yesterday 850 mb at Jacksonville (ms -1 ) 6.2 5.6 3.5 4.3 Wind speed yesterday 850 mb at Tallahassee (ms -1 ) 4.8 2.5 2.7 3.8 Wind speed AM 850 mb at Jacksonville (ms -1 ) 6.7 7.6 4.7 5.2 Wind speed AM 850 mb at Tallahassee (ms -1 ) 5.7 4.1 5.0 3.5 Wind speed PM 850 mb at Jacksonville (ms -1 ) 5.4 7.6 3.3 4.8 Wind speed PM 850 mb at Tallahassee (ms -1 ) 4.9 5.2 2.2 4.3 Wind direction yesterday 850 mb at Jacksonville (degrees) 315 360 315 326 Wind direction yesterday 850 mb at Tallahassee (degrees) 360 326 90 14 Wind direction AM 850 mb at Jacksonville (degrees) 270 27 45 326 Wind direction AM 850 mb at Tallahassee (degrees) 297 333 135 270 Wind direction PM 850 mb at Jacksonville (degrees) 270 27 315 326 Wind direction PM 850 mb at Tallahassee (degrees) 342 27 315 333 Recirculation at Jacksonville 0.1 0.0 0.0 0.1 Cloud average 1.6 1.4 1.8 1.9Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-135 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15p. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Shenandoah.
The ranges in PM2.5 for Categories 3 and 4 are 17.5-22.5 and ≥ 22.5 μ gm-3.

Class 3 Class 4 Bin 13 Bin 25 Bin 28 Bin 16 Visibility Parameters Yesterday's FM at Richmond (μg/m 3 ) 18.5 28.2 27.6 18.6 Yesterday's FM at DC (μg/m 3 ) 22.5 29.7 32.6 24.5 Yesterday's FM at Columbus (μg/m 3 ) 17.5 28.5 34.4 34.2 Surface Meteorological Parameters Max. surface temperature (°C) 21.2 21.6 24.1 22.9 Min. surface temperature (°C) 14.8 13.2 18.4 15.7 Relative humidity (%) 83.4 76.8 76.5 71.7 Surface wind speed (ms -1 ) 1.1 2.3 1.5 0.7 Surface wind direction (degrees) 180 315 207 117 Persistence 0.7 0.9 0.8 0.5 Rainfall (inches) 0.5 0.8 0.4 0.4 Rain (# periods) 0.1 0.1 0.0 0.1 Solar radiation (W/m 2 ) 568 698 690 568 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.0 15.4 18.5 15.6 Temperature PM 850 mb (°C) 16.6 15.3 18.9 17.3 Stability at Dulles (°C) -0.8 0.6 1.6 2.8 Geopotential height difference 700 mb at Dulles (m) 23.4 -25.8 6.0 5.7 Wind speed yesterday 700 mb at Dulles (ms -1 ) 8.0 12.2 6.9 5.1 Wind speed yesterday 700 mb at Roanoke (ms -1 ) 7.5 9.7 5.8 5.4 Wind direction yesterday 700 mb at Dulles (degrees) 293 270 311 342 Wind direction yesterday 700 mb at Roanoke (degrees) 278 236 360 304 Wind speed yesterday 850 mb at Dulles (ms -1 ) 5.1 7.0 6.5 3.7 Wind speed yesterday 850 mb at Roanoke (ms -1 ) 3.6 7.3 4.0 2.2 Wind speed AM 850 mb at Dulles (ms -1 ) 4.5 10.7 6.1 3.2 Wind speed AM 850 mb at Roanoke (ms -1 ) 4.2 12.1 7.3 3.7 Wind speed PM 850 mb at Dulles (ms -1 ) 4.3 11.8 7.8 3.6 Wind speed PM 850 mb at Roanoke (ms -1 ) 4.1 12.2 5.9 3.2 Wind direction yesterday 850 mb at Dulles (degrees) 288 236 291 252 Wind direction yesterday 850 mb at Roanoke (degrees) 315 270 309 270 Wind direction AM 850 mb at Dulles (degrees) 259 252 297 315 Wind direction AM 850 mb at Roanoke (degrees) 259 284 288 304 Wind direction PM 850 mb at Dulles (degrees) 256 270 278 315 Wind direction PM 850 mb at Roanoke (degrees) 211 284 281 180 Recirculation at Dulles 0.2 0.0 0.1 0.5 Cloud average 2.2 1.6 1.7 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-136 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15q. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Shining Rock.
The ranges in PM2.5 for Categories 3 and 4 are 15-20 and ≥ 20 μ gm-3.

Class 3 Class 4 Bin 10 Bin 27 Bin 21 Bin 23 Visibility Parameters Yesterday's FM at Knoxville (μg/m 3 ) 19.6 30.6 31.0 35.8 Yesterday's FM at Charlotte (μg/m 3 ) 16.6 23.9 22.7 27.8 Yesterday's FM at Greenville (μg/m 3 ) 16.0 27.2 28.7 28.8 Surface Meteorological Parameters Max. surface temperature (°C) 26.4 28.1 26.3 28.1 Min. surface temperature (°C) 13.1 17.9 16.2 15.8 Relative humidity (%) 74.5 81.3 74.6 73.7 Surface wind speed (ms -1 ) 1.2 1.1 1.1 1.5 Surface wind direction (degrees) 180 351 297 360 Persistence 0.7 0.6 0.7 0.7 Sea level pressure (mb) 1024 1018 1018 1020 Rainfall (inches) 0.0 0.1 0.0 0.0 Rain (# periods) 26.4 28.1 26.3 28.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14.0 17.0 15.0 16.0 Temperature PM 850 mb (°C) 15.2 17.6 15.1 17.3 Stability at Greensboro (°C) 0.5 -0.4 0.4 0.7 Geopotential height difference 700 mb at Greensboro (m) 13.2 -16.4 17.8 -3.2 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 8.7 7.4 9.2 6.9 Wind direction yesterday 700 mb at Greensboro (degrees) 304 297 284 342 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 5.3 6.1 5.1 4.8 Wind speed AM 850 mb at Greensboro (ms -1 ) 5.7 5.7 4.1 5.1 Wind speed PM 850 mb at Greensboro (ms -1 ) 5.7 5.1 2.7 7.1 Wind direction yesterday 850 mb at Greensboro (degrees) 270 281 315 284 Wind direction AM 850 mb at Greensboro (degrees) 297 292 270 293 Wind direction PM 850 mb at Greensboro (degrees) 198 256 360 278 Recirculation at Greensboro 0.1 0.0 0.0 0.0 Cloud average 2.1 1.9 1.6 1.6Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-137 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15r. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Sipsey.
The ranges in PM2.5 for Categories 3 and 4 are 17.5-22.5 and ≥ 22.5 μ gm-3.

Class 3 Class 4
Bin 29 Bin 22 Bin 30 Visibility Parameters Yesterday's FM at Birmingham (μg/m 3 ) 33.1 43.3 45.6 Yesterday's FM at Atlanta (μg/m 3 ) 28.6 26.4 35.3 Yesterday's FM at Nashville (μg/m 3 ) 18.9 17.9 33.0 Yesterday's FM at Memphis (μg/m 3 ) 20.1 24.0 29.4 Surface Meteorological Parameters Max. surface temperature (°C) 31.3 24.3 30.8 Min. surface temperature (°C) 18.5 9.6 16.8 Relative humidity (%) 70.4 69.8 66.7 Surface wind speed (ms -1 ) 1.3 1.2 1.1 Surface wind direction (degrees) 63 270 270 Persistence 0.8 0.6 0.7 Sea level pressure (mb) 1018 1022 1021 Rainfall (inches) 0.1 0.0 0.0 Rain (# periods) 0.3 0.0 0.5 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.0 9.6 15.0 Temperature PM 850 mb (°C) 17.9 12.5 16.0 Stability at Birmingham (°C) 1.5 1.4 2.5 Geopotential height difference 700 mb at Birmingham (m) -2.0 24.0 -0.5 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 5.4 11.2 5.7 Wind direction yesterday 700 mb at Birmingham (degrees) 45 207 60 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 5.5 6.7 4.3 Wind speed AM 850 mb at Birmingham (ms -1 ) 4.5 9.0 4.9 Wind speed PM 850 mb at Birmingham (ms -1 ) 4.6 7.0 4.9 Wind direction yesterday 850 mb at Birmingham (degrees) 27 207 74 Wind direction AM 850 mb at Birmingham (degrees) 180 225 108 Wind direction PM 850 mb at Birmingham (degrees) 360 243 90 Recirculation at Birmingham 0.1 0.0 0.2 Cloud average 1.4 2.0 1.5Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-138 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15s. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site St. Marks.
The ranges in PM2.5 for Categories 3 and 4 are 15-17.5 and ≥ 17.5 μ gm-3.

Class 3 Class 4
Bin 22 Bin 30 Bin 19 Visibility Parameters Yesterday's FM at Orlando (μg/m 3 ) 16.4 17.6 11.3 Yesterday's FM at Pensacola (μg/m 3 ) 20.3 16.5 24.8 Surface Meteorological Parameters Max. surface temperature (°C) 22.6 35.7 26.2 Min. surface temperature (°C) 4.9 23.6 14.9 Relative humidity (%) 68.4 70.6 73.6 Surface wind speed (ms -1 ) 0.6 0.9 1.5 Surface wind direction (degrees) 360 315 360 Persistence 0.5 0.4 0.6 Sea level pressure (mb) 1022 1016 1023 Rainfall (inches) 0.0 0.0 0.1 Rain (# periods) 0.5 0.5 0.7 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 11.8 19.2 14.3 Temperature PM 850 mb (°C) 11.6 19.5 13.0 Stability at Tallahassee (°C) 7.9 -0.1 -0.8 Geopotential height difference 700 mb at Tallahassee (m) 13.6 -13.0 12.7 Wind speed yesterday 700 mb at Tallahassee (ms -1 ) 8.3 4.4 8.7 Wind direction yesterday 700 mb at Tallahassee (degrees) 270 0 315 Wind speed yesterday 850 mb at Tallahassee (ms -1 ) 7.9 4.6 5.6 Wind speed AM 850 mb at Tallahassee (ms -1 ) 6.5 3.3 5.6 Wind speed PM 850 mb at Tallahassee (ms -1 ) 4.8 4.2 4.2 Wind direction yesterday 850 mb at Tallahassee (degrees) 342 18 315 Wind direction AM 850 mb at Tallahassee (degrees) 315 270 284 Wind direction PM 850 mb at Tallahassee (degrees) 342 n/a 360 Recirculation at Tallahassee 0.0 0.3 0.2 Cloud average 1.5 1.8 1.3Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-139 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15t. Summary of Average Input Parame ters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Swanquarter.
The ranges in PM2.5 for Categories 3 and 4 are 12.5-17.5 and ≥ 17.5 μ gm-3.

Class 3 Class
Bin 21 Bin 17 Bin 13 Bin 28 Visibility Parameters Yesterday's FM at Raleigh (μg/m 3 ) 21.7 22.4 21.6 34.9 Yesterday's FM at Norfolk (μg/m 3 ) 19.2 15.2 19.7 35.8 Surface Meteorological Parameters Max. surface temperature (°C) 26.5 25.4 15.7 29.7 Min. surface temperature (°C) 20.7 17.9 7.2 24.0 Relative humidity (%) 90.8 82.1 77.5 81.5 Surface wind speed (ms -1 ) 3.5 3.0 1.6 4.2 Surface wind direction (degrees) 210 243 349 270 Persistence 0.8 0.7 0.6 0.9 Sea level pressure (mb) 1017 1020 1025 1016 Rainfall (inches) 0.0 0.1 0.0 0.1 Rain (# periods) 0.5 0.8 0.2 0.3 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 16.6 14.7 8.8 17.7 Temperature PM 850 mb (°C) 17.3 14.6 9.9 18.9 Stability at Moorhead (°C) -0.1 -1.7 6.9 -1.5 Geopotential height difference 700 mb at Moorhead (m) -6.2 4.8 11.2 -11.0 Wind speed yesterday 700 mb at Moorhead (ms -1 ) 8 12 10 7 Wind direction yesterday 700 mb at Moorhead (degrees) 276 270 304 342 Wind speed yesterday 850 mb at Moorhead (ms -1 ) 6 9 7 4 Wind speed AM 850 mb at Moorhead (ms -1 ) 7.3 9.1 6.7 7.7 Wind speed PM 850 mb at Moorhead (ms -1 ) 6.3 7.3 7.0 7.2 Wind direction yesterday 850 mb at Moorhead (degrees) 270 270 326 315 Wind direction AM 850 mb at Moorhead (degrees) 275 270 304 288 Wind direction PM 850 mb at Moorhead (degrees) 270 270 315 270 Recirculation at Moorhead 0.1 0.2 0.0 0.0 Cloud average 1.6 1.8 1.0 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-140 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-15u. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for IMPROVE Site Upper Buffalo.
The ranges in PM2.5 for Categories 3 and 4 are 15-17.5 and ≥ 17.5 μ gm-3.

Class 3 Class 4 Bin 23 Bin 28 Bin 30 Bin 32 Visibility Parameters Yesterday's FM at Little Rock (μg/m 3 ) 17.6 25.8 23.4 30.0 Yesterday's FM at Dallas (μg/m 3 ) 17.5 21.1 16.6 24.8 Surface Meteorological Parameters Max. surface temperature (°C) 29.3 23.9 33.6 32.2 Min. surface temperature (°C) 17.4 14.0 21.0 20.4 Relative humidity (%) 73.0 78.4 68.9 69.4 Surface wind speed (ms -1 ) 2.4 2.2 1.7 1.7 Surface wind direction (degrees) 166 135 90 194 Persistence 0.8 0.8 0.8 0.7 Sea level pressure (mb) 1020 1020 1018 1018 Rainfall (inches) 0.0 0.2 0.0 0.0 Rain (# periods) 0.0 0.5 0.0 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 16.4 13.5 19.2 18.2 Temperature PM 850 mb (°C) 17.7 13.5 19.3 19.5 Stability at Little Rock (°C) -2.9 -1.4 -2.7 -1.1 Geopotential height difference 700 mb at Little Rock (m) 25.5 -9.4 6.8 0.4 Wind speed yesterday 700 mb at Little Rock (ms -1 ) 4.9 2.7 8.1 5.2 Wind direction yesterday 700 mb at Little Rock (degrees) 360 225 45 45 Wind speed yesterday 850 mb at Little Rock (ms -1 ) 4.4 2.2 3.9 3.8 Wind speed AM 850 mb at Little Rock (ms -1 ) 5.3 4.5 4.1 3.7 Wind speed PM 850 mb at Little Rock (ms -1 ) 4.2 4.9 4.5 3.3 Wind direction yesterday 850 mb at Little Rock (degrees) 117 162 45 270 Wind direction AM 850 mb at Little Rock (degrees) 243 252 90 259 Wind direction PM 850 mb at Little Rock (degrees) 194 180 90 236 Recirculation at Little Rock 0.4 0.3 0.8 0.4 Cloud average 1.8 1.5 1.5 1.6



### We discuss the findings for Cape Romain, Great Smoky Mountains, and Mammoth Cave below.
For Cape Romain, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 15 to 17.5 and greater than or equal to 17.5 μ gm -3 

### , respectively. There are two Category 3 and two Category 4 bins that meet the criteria for key bins. One of the Category 3 bins represents a fall, winter, or early spring regime, and is characterized by a relatively low average maximum temperature. The remaining three bins are characterized by high temperatures, low to moderate surface wind speeds, and moderate relative humidity, and these vary relative to one another among the bins. Prior day PM 2.5 

### values for Charleston are in the range of 13 to 29 μ gm -3 

### , and are highest for the Category 4 bins. Average surface wind direction is southwesterly for three of the key bins, and southeasterly for the remaining key bin. Recirculation by the sea breeze (as indicated by persistence) appears to be important for Bin 22, which is a Category 5 bin. Stability is greatest, on average, for the cooler days in Bin 15. Upper-air wind speeds and directions vary slightlyCharacterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-141 VISTAS Meteorological Characterization

06-046 December 8, 2006 

### among the bins. Wind speeds are highest for the cooler regime (Bin 15). Morning and evening 850 mb wind directions are northwesterly for all bins. A comparison of the two Category 4 bins shows that Bin 22 has lower temperatures, higher humidity, lower surface wind speeds, southeasterly surface winds, and greater cloud cover. Bin 33 has higher temperatures, lower humidity, higher surface wind speeds, southwesterly surface winds, and less cloud cover. Clearly, different combinations of local parameters can result in high PM 2.5 

### concentrations.

For GSM, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 17.5 to 25 and greater than or equal to 25 μ gm -3 

### , respectively. All four key bins are characterized by very low surface wind speeds and relatively high temperatures. All but one of the key bins is characterized by greater than 80 percent relative humidity. The Category 4 bin has the highest prior-day PM 2.5 

### concentrations at the three potential upwind areas (Knoxville, Atlanta, and Charlotte). The greatest differences among the bins are the wind di rections. An anticyclonic circulation aloft (a high pressure system) over the GSM region is indicated by the upper-level wind directions (southwesterly winds over Nashville, northwest erly winds over Greensboro, and southeasterly winds over Atlanta) for Bin 24 (the Category 4 bin).

For Mammoth Cave, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 20 to 25 and greater than or equal to 25 μ gm -3 

### , respectively. All four key bins are characterized by high temperatures. Relative humidity varies among the bins and is lowest for Bin 21 (the Category 4 bin). Average surface wind speed is very low for three of the bins, and somewhat higher (moderate) for Bin 30 (one of the Category 3 bins). Prior day PM 2.5 

### values for Nashville, Knoxville, and Louisville vary among the bins, and the variation is not consistent among the three sites. Bin 5 is distinguished by low prior-day PM 2.5 

### values for all three potential upwind areas. Average surface wind direction is southwesterly for Bins 30 and 21, southeasterly for Bin 24, and not available (unable to be calculated) for Bin 5. Morning and evening 850 mb wind directions vary considerably among the key bins. Bin 21, the Category 4 bin, is distinguished from the Category 3 bins by higher prior-day PM 2.5 

### concentrations at all three potential upwind sites, lower relative humidity, and a shift from northwesterly to southerly winds aloft during the daytime hours.
Figure 3-7 shows the average composition for all key PM 2.5 

### bins for each of the IMPROVE sites.Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7a. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Breton.

Breton Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00

7 (119) 1 (44) 11 (23) 4 (21) 13 (9) 8 (4) 19 (13) 27 (7) 21 (10)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7b. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Brigantine.

Brigantine Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (219) 8 (91) 16 (12) 25 (12) 23 (14) 29 (4) 31 (12)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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### 3-142 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7c. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Cadiz.

Cadiz Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

8 (141) 14 (39) 27 (29) 24 (13) 21 (12) 23 (8) 6 (5) 30 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7d. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Caney Creek.

Caney Creek Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00

3 (164) 18 (43) 5 (26) 11 (14) 22 (12) 31 (10) 13 (7) 32 (6) 27 (5) 29 (10)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-143 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7e. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Cape Romain.

Cape Romain Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00

1 (191) 13 (59) 8 (37) 29 (17) 20 (14) 18 (11) 6 (10) 15 (4) 31 (4) 22 (11) 33 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7f. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Chassahowitzka.

Chassahowitzka Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00

5 (117) 2 (23) 22 (21) 23 (6) 21 (9) 12 (5) 13 (10) 8 (8) 27 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-144 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7g. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Cohutta.

Cohutta Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (179) 7 (26) 5 (15) 13 (18) 2 (11) 23 (9) 21 (10) 29 (12)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7h. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Dolly Sods.

Dolly Sods Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00

4 (237) 10 (23) 1 (20) 17 (34) 7 (22) 21 (11) 18 (4) 23 (11) 27 (4)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-145 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7i. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Everglades.

Everglades Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00

1 (184) 11 (65) 7 (17) 28 (25) 15 (19) 19 (9) 21 (5) 27 (5) 2 (4)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7j. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Great Smoky Mountains.

Great Smoky Mountains Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

3 (291) 4(42) 17 (20) 20 (20) 22 (12) 5 (8) 11 (10) 13 (7) 26 (7) 24 (14)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-146 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7k. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site James River Face.

James River Face Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (174) 25 (51) 28 (45) 9 (28) 26 (18) 19 (12) 23 (8) 14 (4) 16 (8)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7l. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Linville Gorge.

Linville Gorge Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (227) 6 (49) 21 (17) 18 (22) 15 (11) 31 (9) 30 (5) 19 (5) 25 (15)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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### 3-147 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7m. Average Elemental Carbon (EC), Nitr ate (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Mammoth Cave.

Mammoth Cave Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

10 (221) 1 (55) 19 (25) 9 (22) 13 (14) 30 (10) 5 (4) 24 (4) 21 (16)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7n. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Mingo.

Mingo Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00

14 (68) 1 (26) 12 (10) 22 (9) 7 (7) 18 (10) 8 (5) 21 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-148 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7o. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Okefenokee.

Okefenokee Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

18 (157) 1 (51) 8 (37) 10 (17) 12 (10) 27 (14) 28 (14) 31 (5) 3 (4) 30 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7p. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Shenandoah.

Shenandoah Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

2 (202) 3 (43) 18 (30) 20 (15) 22 (13) 13 (12) 25 (5) 28 (13) 16 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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### 3-149 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7q. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Shining Rock.

Shining Rock Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

5 (191) 20 (37) 4 (19) 14 (15) 9 (15) 10 (8) 27 (7) 21 (5) 23 (12)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7r. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Sipsey.

Sipsy Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (190) 8 (41) 16 (18) 15 (10) 3 (8) 24 (8) 29 (7) 22 (3) 30 (11)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-150 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7s. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site St Mark’s.

St. Marks Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00

4 (90) 5 (50) 7 (29) 27 (13) 13 (10) 9 (9) 22 (4) 30 (4) 19 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-7t. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Swanquarter.

Swanquarter Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00

5 (160) 24 (29) 16 (11) 12 (9) 21 (13) 17 (5) 13 (6) 28 (4)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-151 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-7u. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: IMPROVE Site Upper Buffalo.

Upper Buffalo Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00

2 (167) 17 (33) 21 (38) 20 (15) 12 (10) 23 (5) 28 (4) 30 (4) 32 (16)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4



### The compositional charts for PM 2.5 

### also clearly illustrate that the relative contributions of various PM 2.5 

### components vary by bin for each of the sites. As for visibility, the high PM 2.5 

### concentration bins are distinguished from the lower concentration bins by higher sulfate and organic matter concentrations, and, in many cases, lower nitrate concentrations. Within each category, the variations among the bins are due to differences in meteorology as well as regional pollutant transport.
Table 3-16 summarizes the characteristics for key Category 3 and 4 bins for the STN monitoring sites.

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### 3-152 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-153 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16a. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Birmingham.
The ranges in PM2.5 for Categories 3 and 4 are 32.5-40 and ≥ 40 μ gm-3.

Class 3 Class 4
Bin 11 Bin 26 Bin 19 Bin 10
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 30.5 32.6 50.7 32.4 Yesterday's FM at Atlanta (μg/m 3 ) 23.2 24.1 37.6 25.6 Yesterday's FM at Memphis (μg/m 3 ) 21.5 27.9 28.3 22.2 Yesterday's FM at Nashville (μg/m 3 ) 22.0 31.3 27.7 19.5 Surface Meteorological Parameters Max. surface temperature (°C) 27.9 34.0 28.3 29.6 Min. surface temperature (°C) 14.8 22.7 14.5 14.6 Relative humidity (%) 61.3 61.2 63.1 61.6 Surface wind speed (ms -1 ) 1.0 2.2 0.7 0.3 Surface wind direction (degrees) 90 81 342 112 Persistence 0.7 0.9 0.8 0.5 Sea level pressure (mb) 1021 1017 1022 1023 Rainfall (inches) 0.0 0.0 0.0 0.0 Rain (# periods) 0.3 0.3 0.1 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 13.8 18.2 13.6 14.6 Temperature PM 850 mb (°C) 15.0 19.3 14.4 15.9 Stability at Birmingham (°C) 3.6 0.8 4.5 4.0 Geopotential height difference 700 mb at Birmingham (m) -3.2 6.7 1.3 5.9 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 6.9 9.2 5.8 6.0 Wind direction yesterday 700 mb at Birmingham (degrees) 24 22 34 22 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 4.6 6.5 3.6 4.5 Wind speed AM 850 mb at Birmingham (ms -1 ) 5.5 4.6 3.7 4.0 Wind speed PM 850 mb at Birmingham (ms -1 ) 5.1 6.9 2.9 3.2 Wind direction yesterday 850 mb at Birmingham (degrees) 24 22 34 22 Wind direction AM 850 mb at Birmingham (degrees) 243 56 270 45 Wind direction PM 850 mb at Birmingham (degrees) 60 68 270 180 Recirculation at Birmingham 0.1 0.0 0.4 0.2 Cloud average 1.6 1.7 1.5 1.5Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-154 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16b. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Charlotte.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 3 Class 4 Bin 31 Bin 15 Bin 12 Bin 18 Bin 26
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 28.2 33.4 20.6 23.2 35.2 Yesterday's FM at Charlotte (μg/m 3 ) 28.6 20.1 19.3 18.8 32.2 Yesterday's FM at Greenville-Spartanburg (μg/m 3 ) 27.2 19.0 18.3 18.3 30.4 Yesterday's FM at Winston-Salem (μg/m 3 ) 29.2 19.7 20.8 22.4 31.7 Surface Meteorological Parameters Max. surface temperature (°C) 31.2 23.6 26.0 33.7 29.2 Min. surface temperature (°C) 19.7 10.6 16.5 20.3 16.7 Relative humidity (%) 70.2 66.8 71.0 62.2 69.1 Surface wind speed (ms -1 ) 1.8 1.3 1.6 1.1 1.2 Surface wind direction (degrees) 207 194 102 209 185 Persistence 0.7 0.8 0.6 0.7 0.7 Sea level pressure (mb) 1019 1022 1021 1018 1020 Rainfall (inches) 0.2 0.0 0.4 0.0 0.0 Rain (# periods) 0.6 0.2 0.6 0.3 0.3 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.1 10.3 12.1 18.2 15.2 Temperature PM 850 mb (°C) 17.6 12.2 12.7 19.5 15.7 Stability at Greensboro (°C) 0.5 3.6 -0.4 1.7 1.4 Geopotential height difference 700 mb at Greensboro (m) -6.6 6.6 25.5 2.3 -1.5 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 9.1 9.2 10.0 7.0 6.5 Wind direction yesterday 700 mb at Greensboro (degrees) 286 288 306 319 326 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 5.8 5.4 5.5 4.1 5.0 Wind speed AM 850 mb at Greensboro (ms -1 ) 8.6 6.1 4.7 5.1 3.9 Wind speed PM 850 mb at Greensboro (ms -1 ) 7.0 7.5 4.1 5.2 5.2 Wind direction yesterday 850 mb at Greensboro (degrees) 259 247 301 301 309 Wind direction AM 850 mb at Greensboro (degrees) 278 246 307 323 302 Wind direction PM 850 mb at Greensboro (degrees) 273 270 n/a 270 278 Recirculation at Greensboro 0 0.1 0.3 0.1 0.2 Cloud average 1.8 1.4 2 1.7 1.5Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-155 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16c. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Chattanooga.
The ranges in PM2.5 for Categories 3 and 4 are 25-32.5 and ≥ 32.5 μ gm-3.

Class 3 Class 4
Bin 22 Bin 19 Bin 21 Bin 28
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 34.5 30.2 36.9 44.8 Yesterday's FM at Atlanta (μg/m 3 ) 24.4 23.3 27.1 45.4 Yesterday's FM at Knoxville (μg/m 3 ) 25.9 26.4 26.5 44.7 Surface Meteorological Parameters Max. surface temperature (°C) 30.0 29.8 34.3 26.1 Min. surface temperature (°C) 16.7 18.7 21.1 13.9 Relative humidity (%) 69.6 73.3 61.2 73.2 Surface wind speed (ms -1 ) 0.8 0.8 1.7 0.7 Surface wind direction (degrees) 225 194 243 180 Persistence 0.8 0.6 0.7 0.8 Sea level pressure (mb) 1022 1021 1017 1024 Rainfall (inches) 0.1 0.1 0.1 0.0 Rain (# periods) 0.3 0.9 0.6 0.5 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.8 14.7 18.6 12.5 Temperature PM 850 mb (°C) 16.3 16.0 19.1 12.9 Stability at Atlanta (°C) 4.5 3.2 5.3 4.9 Geopotential height difference 700 mb at Atlanta (m) -7.4 -3.4 -4.5 -9.1 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 6.1 5.3 5.6 3.9 Wind speed yesterday 700 mb at Nashville (ms -1 ) 7.6 7.5 6.4 5.6 Wind direction yesterday 700 mb at Atlanta (degrees) 34 108 27 117 Wind direction yesterday 700 mb at Nashville (degrees) 270 243 326 90 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 4.4 4.2 3.8 4.3 Wind speed yesterday 850 mb at Nashville (ms -1 ) 4.4 5.5 4.6 4.6 Wind speed AM 850 mb at Atlanta (ms -1 ) 4.6 4.5 4.9 4.3 Wind speed AM 850 mb at Nashville (ms -1 ) 7.7 7.3 6.7 6.9 Wind speed PM 850 mb at Atlanta (ms -1 ) 5.3 4.1 6.0 6.0 Wind speed PM 850 mb at Nashville (ms -1 ) 6.2 6.3 6.2 6.5 Wind direction yesterday 850 mb at Atlanta (degrees) 90 90 360 90 Wind direction yesterday 850 mb at Nashville (degrees) 180 281 326 207 Wind direction AM 850 mb at Atlanta (degrees) 270 90 360 90 Wind direction AM 850 mb at Nashville (degrees) 236 248 307 236 Wind direction PM 850 mb at Atlanta (degrees) 127 90 27 225 Wind direction PM 850 mb at Nashville (degrees) 214 217 297 225 Cloud average 1.9 2.1 1.9 1.9Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-156 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16d. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Greenville-Spartanburg.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 3 Class 4 Bin 20 Bin 25 Bin 22 Bin32 Bin 21 Bin30
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 27.1 36.1 24.9 40.2 26.0 30.1 Yesterday's FM at Columbus (μg/m 3 ) 17.7 28.4 16.6 29.3 17.9 25.4 Yesterday's FM at Charlotte (μg/m 3 ) 23.9 30.1 24.8 32.9 26.3 25.5 Yesterday's FM at Greensboro (μg/m 3 ) 25.2 32.8 24.6 34.1 26.7 23.3 Surface Meteorological Parameters Max. surface temperature (°C) 28.0 28.9 29.5 28.5 26.8 29.6 Min. surface temperature (°C) 17.3 18.9 19.2 18.0 13.4 20.1 Relative humidity (%) 67.8 75.7 70.2 71.9 69.6 70.6 Surface wind speed (ms -1 ) 2.2 1.4 2.1 1.8 1.9 1.4 Surface wind direction (degrees) 195 236 63 236 112 90 Persistence 0.8 0.7 0.8 0.8 0.8 0.8 Sea level pressure (mb) 1019 1018 1021 1020 1022 1020 Rainfall (inches) 0.0 0.2 0.0 0.1 0.0 0.0 Rain (# periods) 0.6 0.9 0.5 0.4 0.0 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14.3 15.8 15.8 14.8 13.1 15.5 Temperature PM 850 mb (°C) 16.1 16.2 16.5 15.5 14.1 16.8 Stability at Atlanta (°C) 2.4 2.1 0.0 3.0 2.7 2.5 Geopotential height difference 700 mb at Atlanta (m) -6.5 -20.5 9.2 9.8 -10.3 14.1 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 6.0 5.6 4.82 5.5 6.5 6.6 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 8.4 6.2 4.4 7.3 5.9 5.1 Wind direction yesterday 700 mb at Atlanta (degrees) 278 14 108 310 45 34 Wind direction yesterday 700 mb at Greensboro (degrees) 283 326 270 287 9 346 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 5.0 4.9 4.4 4.2 4.8 3.5 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 5.9 5.9 6.2 5.4 4.0 3.7 Wind speed AM 850 mb at Atlanta (ms -1 ) 6.8 5.0 5.0 5.3 4.2 4.0 Wind speed AM 850 mb at Greensboro (ms -1 ) 7.6 5.2 6.5 6.1 3.5 3.7 Wind speed PM 850 mb at Atlanta (ms -1 ) 6.4 4.9 5.3 5.1 4.2 4.1 Wind speed PM 850 mb at Greensboro (ms -1 ) 7.0 5.9 5.1 6.6 3.9 4.6 Wind direction yesterday 850 mb at Atlanta (degrees) 140 284 79 171 90 360 Wind direction yesterday 850 mb at Greensboro (degrees) 270 270 56 270 27 31 Wind direction AM 850 mb at Atlanta (degrees) 239 360 59 234 227 34 Wind direction AM 850 mb at Greensboro (degrees) 257 307 74 266 27 34 Wind direction PM 850 mb at Atlanta (degrees) 250 207 74 211 146 90 Wind direction PM 850 mb at Greensboro (degrees) 249 270 90 274 225 90 Cloud average 2.0 2.2 2.4 1.9 2.0 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-157 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16e. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Hickory.

The ranges in PM2.5 for Categories 3 and 4 are 27.5-32.5 and ≥ 32.5 μ gm-3.

Class 3 Class 4
Bin 29 Bin 27 Bin 22 Bin 17
PM 2.5

Parameters Yesterday's FM at Charlotte (μg/m 3 ) 27.7 29.3 30.4 21.5 Yesterday's FM at Greensboro (μg/m 3 ) 25.6 33.9 30.3 21.6 Yesterday's FM at Knoxville (μg/m 3 ) 29.0 34.2 36.5 23.5 Yesterday's FM at Winston-Salem (μg/m 3 ) 31.3 29.4 31.9 19.1 Surface Meteorological Parameters Max. surface temperature (°C) 28.5 25.8 29.5 23.5 Min. surface temperature (°C) 17.5 14.7 18.0 12.0 Relative humidity (%) 70.2 71.9 71.5 71.2 Surface wind speed (ms -1 ) 1.9 0.8 0.8 1.4 Surface wind direction (degrees) 315 45 270 14 Persistence 0.8 0.8 0.7 0.8 Sea level pressure (mb) 1020 1019 1020 1023 Rainfall (inches) 0.0 0.0 0.0 0.0 Rain (# periods) 0.5 0.8 0.5 0.4 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.3 14.9 16.2 10.2 Temperature PM 850 mb (°C) 15.6 16.2 16.6 12.1 Stability at Greensboro (°C) 0.3 1.3 -0.9 2.6 Geopotential height difference 700 mb at Greensboro (m) -5.5 2.1 7.7 -4.0 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 7.9 9.3 6.7 8.9 Wind direction yesterday 700 mb at Greensboro (degrees) 288 315 333 284 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 3.6 9.2 3.3 5.9 Wind speed AM 850 mb at Greensboro (ms -1 ) 6.5 7.6 5.8 6.9 Wind speed PM 850 mb at Greensboro (ms -1 ) 6.2 5.0 5.2 5.2 Wind direction yesterday 850 mb at Greensboro (degrees) 288 342 292 360 Wind direction AM 850 mb at Greensboro (degrees) 360 n/a 277 270 Wind direction PM 850 mb at Greensboro (degrees) 225 270 281 45 Recirculation at Greensboro 0.0 0.0 0.2 0.0 Cloud average 1.6 1.5 1.9 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-158 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16f. Summary of Average Input Parame ters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Huntington-Ashland.
The ranges in PM2.5 for Categories 3 and 4 are 25-32.5 and ≥ 32.5 μ gm-3.

Class 3 Class 4
Bin 14 Bin 12 Bin 23
PM 2.5

Parameters Yesterday's FM at Louisville (μg/m 3 ) 27.9 28.7 40.2 Yesterday's FM at Cincinnati (μg/m 3 ) 26.8 24.2 44.7 Surface Meteorological Parameters Max. surface temperature (°C) 27.8 29.4 29.1 Min. surface temperature (°C) 15.8 17.6 17.4 Relative humidity (%) 74.8 77.6 75.0 Surface wind speed (ms -1 ) 1.2 0.8 0.9 Surface wind direction (degrees) 162 135 214 Persistence 0.7 0.6 0.8 Sea level pressure (mb) 1020 1020 1023 Rainfall (inches) 0.0 0.0 0.0 Rain (# periods) 0.8 0.5 0.8 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14.1 15.8 14.7 Temperature PM 850 mb (°C) 15.3 16.7 16.0 Stability at Wilmington (°C) 1.5 2.4 1.3 Geopotential height difference 700 mb at Wilmington (m) -6.6 -7.0 -16.3 Wind speed yesterday 700 mb at Nashville (ms -1 ) 7.6 5.1 4.4 Wind speed yesterday 700 mb at Roanoke (ms -1 ) 4.3 5.9 4.7 Wind direction yesterday 700 mb at Nashville (degrees) 198 360 117 Wind direction yesterday 700 mb at Roanoke (degrees) 297 315 22 Wind speed yesterday 850 mb at Wilmington (ms -1 ) 5.8 5.7 3.5 Wind speed yesterday 850 mb at Nashville (ms -1 ) 5.5 4.2 3.6 Wind speed yesterday 850 mb at Roanoke (ms -1 ) 4.3 5.2 3.8 Wind speed AM 850 mb at Wilmington (ms -1 ) 6.8 4.2 6.4 Wind speed AM 850 mb at Nashville (ms -1 ) 6.9 2.5 3.8 Wind speed AM 850 mb at Roanoke (ms -1 ) 4.2 6.8 6.6 Wind speed PM 850 mb at Wilmington (ms -1 ) 9.4 5.6 6.1 Wind speed PM 850 mb at Nashville (ms -1 ) 6.2 4.0 5.1 Wind speed PM 850 mb at Roanoke (ms -1 ) 4.9 4.9 5.6 Wind direction yesterday 850 mb at Wilmington (degrees) 207 288 236 Wind direction yesterday 850 mb at Nashville (degrees) 194 315 207 Wind direction yesterday 850 mb at Roanoke (degrees) 135 315 14 Wind direction AM 850 mb at Wilmington (degrees) 252 270 281 Wind direction AM 850 mb at Nashville (degrees) 270 225 207 Wind direction AM 850 mb at Roanoke (degrees) 214 288 342 Wind direction PM 850 mb at Wilmington (degrees) 233 270 270 Wind direction PM 850 mb at Nashville (degrees) 207 270 207 Wind direction PM 850 mb at Roanoke (degrees) 169 270 342 Recirculation at Wilmington 0 0.3 0.1 Cloud average 1.8 2.0 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-159 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16g. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Jackson.

The ranges in PM2.5 for Categories 3 and 4 are 22.5-27.5 and ≥ 27.5 μ gm-3.

Class 3 Class 4 Bin 30 Bin 34 Bin 22
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 38.7 42.8 41.3 Yesterday's FM at Memphis (μg/m 3 ) 24.8 23.8 28.0 Yesterday's FM at Gulfport (μg/m 3 ) 24.0 21.2 23.2 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 26.5 25.1 25.7 Surface Meteorological Parameters Max. surface temperature (°C) 29.0 29.7 30.4 Min. surface temperature (°C) 17.3 14.0 17.6 Relative humidity (%) 70.1 67.6 69.9 Surface wind speed (ms -1 ) 1.2 1.4 0.8 Surface wind direction (degrees) 63 90 146 Persistence 0.7 0.9 0.8 Sea level pressure (mb) 1018 1021 1019 Rainfall (inches) 0.1 0.0 0.0 Rain (# periods) 0.7 0.3 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14 16.2 15.1 Temperature PM 850 mb (°C) 16.2 15.3 16.6 Stability at Jacksonville (°C) -0.3 4.7 1.8 Geopotential height difference 700 mb at Jacksonville (m) -3.8 2.3 1.3 Wind speed yesterday 700 mb at Jacksonville (ms -1 ) 5.8 5.8 5.9 Wind direction yesterday 700 mb at Jacksonville (degrees) 270 45 76 Wind speed yesterday 850 mb at Jacksonville (ms -1 ) 4.0 5.4 4.4 Wind speed AM 850 mb at Jacksonville (ms -1 ) 6.7 7.4 3.0 Wind speed PM 850 mb at Jacksonville (ms -1 ) 6.0 6.9 1.7 Wind direction yesterday 850 mb at Jacksonville (degrees) 117 n/a 76 Wind direction AM 850 mb at Jacksonville (degrees) 191 n/a 171 Wind direction PM 850 mb at Jacksonville (degrees) 180 n/a 180 Recirculation at Jacksonville 0.1 0.0 0.4 Cloud average 2 1.6 1.6Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-160 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16h. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Kingsport-Bristol.
The ranges in PM2.5 for Categories 3 and 4 are 25-32.5 and ≥ 32.5 μ gm-3.

Class 3 Class 4
PM 2.5

Parameters Bin 27 Bin 3 Bin 24 Bin 32 Yesterday's FM at Louisville (μg/m 3 ) 28.6 17.1 28.8 41.4 Yesterday's FM at Knoxville (μg/m 3 ) 39.1 24.9 20.5 38.7 Yesterday's FM at Winston-Salem (μg/m 3 ) 28.9 21.1 21.9 26.2 Yesterday's FM at Richmond (μg/m 3 ) 23.3 12.7 19.4 22.1 Surface Meteorological Parameters Max. surface temperature (°C) 30.4 25.9 28.7 27.2 Min. surface temperature (°C) 18.0 12.4 15.7 14.7 Relative humidity (%) 73.0 72.3 75.5 77.4 Surface wind speed (ms -1 ) 0.8 0.6 0.9 0.7 Persistence 0.7 0.7 0.7 0.8 Sea level pressure (mb) 1019 1022 1019 1022 Surface wind direction (degrees) 198 256 236 270 Rainfall (inches) 0.1 0.0 0.1 0.0 Rain (# periods) 0.6 0.0 0.6 0.6 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.2 13.1 15.9 15.3 Temperature PM 850 mb (°C) 18.3 14.3 16.8 16.3 Stability at Roanoke (°C) 2.6 3.9 4.2 5.3 Geopotential height difference 700 mb at Roanoke (m) 2.6 -0.2 3.9 -11.6 Wind speed yesterday 700 mb at Nashville (ms -1 ) 6.2 7.7 6.3 4.6 Wind speed yesterday 700 mb at Roanoke (ms -1 ) 7.9 7.0 6.5 5.2 Wind direction yesterday 700 mb at Nashville (degrees) 270 270 297 360 Wind direction yesterday 700 mb at Roanoke (degrees) 284 286 292 360 Wind speed yesterday 850 mb at Nashville (ms -1 ) 4.9 4.2 5.4 3.6 Wind speed yesterday 850 mb at Roanoke (ms -1 ) 4.6 4.5 5.0 4.3 Wind speed AM 850 mb at Nashville (ms -1 ) 6.7 5.6 8.3 6.1 Wind speed AM 850 mb at Roanoke (ms -1 ) 5.4 5.7 8.8 8.3 Wind speed PM 850 mb at Nashville (ms -1 ) 7.5 5.0 5.7 6.1 Wind speed PM 850 mb at Roanoke (ms -1 ) 5.4 3.5 7.6 6.4 Wind direction yesterday 850 mb at Nashville (degrees) 217 27. 248 194 Wind direction yesterday 850 mb at Roanoke (degrees) 288 214 256 351 Wind direction AM 850 mb at Nashville (degrees) 247 297 270 239 Wind direction AM 850 mb at Roanoke (degrees) 281 315 270 329 Wind direction PM 850 mb at Nashville (degrees) 236 217 256 243 Wind direction PM 850 mb at Roanoke (degrees) 236 .270 236 301 Cloud average 1.9 1.8 2.1 2.0Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-161 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16i. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Louisville.
The ranges in PM2.5 for Categories 3 and 4 are 27.5-37.5 and ≥ 37.5 μ gm-3.

Class 3 Class 4 Bin 15 Bin 30 Bin 17 Bin 24 Bin 25 Bin 29
PM 2.5

Parameters Yesterday's FM at Nashville (μg/m 3 ) 16.7 28.5 29.0 29.4 29.1 25.9 Yesterday's FM at Louisville (μg/m 3 ) 29.5 37.0 31.1 35.7 38.5 33.3 Yesterday's FM at Cincinnati (μg/m 3 ) 25.7 37.6 31.9 32.5 32.2 32.6 Yesterday's FM at St. Louis (μg/m 3 ) 15.9 29.9 17.9 32.0 27.4 28.6 Surface Meteorological Parameters Max. surface temperature (°C) 32.4 26.3 32.8 28.9 34.1 22.6 Min. surface temperature (°C) 22.4 16.2 22.3 18.1 22.2 12.5 Relative humidity (%) 67.3 69.4 65.6 68.9 55.4 78.1 Surface wind speed (ms -1 ) 1.7 2.8 2.8 1.6 1.1 1.0 Surface wind direction (degrees) 243 202 221 225 9. 135 Persistence 0.7 0.8 0.8 0.7 0.7 0.6 Sea level pressure (mb) 1017 1020 1018 1019 1023 1023 Rainfall (inches) 0.1 0.1 0.2 0.1 0.0 0.1 Rain (# periods) 0.6 0.5 0.7 0.6 0.0 0.5 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.1 13.8 17.2 14.8 17.2 11.6 Temperature PM 850 mb (°C) 17.8 14.0 17.8 15.4 18.6 11.8 Stability at Wilmington (°C) 1.4 2.5 0.3 2.8 2.9 1.7 Geopotential height difference 700 mb at Wilmington (m) -11.0 -2.4 -12.5 -7.8 14.3 16.5 Wind speed yesterday 700 mb at Wilmington (ms -1 ) 5.8 9.6 11.1 5.6 4.2 10.0 Wind speed yesterday 700 mb at Nashville (ms -1 ) 5.3 7.4 5.3 5.9 5.5 7.7 Wind direction yesterday 700 mb at Wilmington (degrees) 284 286 270 299 243 297 Wind direction yesterday 700 mb at Nashville (degrees) 288 207 180 351 117 45 Wind speed yesterday 850 mb at Wilmington (ms -1 ) 5.0 7.6 8.8 3.1 2.2 8.5 Wind speed yesterday 850 mb at Nashville (ms -1 ) 3.9 3.9 5.0 3.5 2.8 6.1 Wind speed AM 850 mb at Wilmington (ms -1 ) 4.9 10.1 9.8 5.9 3.0 5.8 Wind speed AM 850 mb at Nashville (ms -1 ) 3.9 6.8 6.9 5.2 4.2 5.6 Wind speed PM 850 mb at Wilmington (ms -1 ) 6.4 9.4 9.4 6.7 2.7 5.0 Wind speed PM 850 mb at Nashville (ms -1 ) 4.6 6.5 6.4 5.2 3.2 4.8 Wind direction yesterday 850 mb at Wilmington (degrees) 315 254 266 225 117 315 Wind direction yesterday 850 mb at Nashville (degrees) 297 270 197 117 108 315 Wind direction AM 850 mb at Wilmington (degrees) 270 277 266 273 315 360 Wind direction AM 850 mb at Nashville (degrees) 243 254 250 259 45 45 Wind direction PM 850 mb at Wilmington (degrees) 262 279 264 275 117 360 Wind direction PM 850 mb at Nashville (degrees) 270 236 229 261 76 135 Cloud average 2.0 1.7 1.8 1.9 1.7 1.7Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-162 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16j. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Macon.
The ranges in PM2.5 for Categories 3 and 4 are 25-30 and ≥ 30 μ gm-3.

Class 3 Class 4
Bin 19 Bin 14
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 30.0 31.1 Surface Meteorological Parameters Max. surface temperature (°C) 33.8 27.1 Min. surface temperature (°C) 20.9 10.4 Relative humidity (%) 68.2 67.2 Surface wind speed (ms -1 ) 0.6 0.7 Surface wind direction (degrees) 153 225 Persistence 0.4 0.7 Sea level pressure (mb) 1017 1021 Rainfall (inches) 0.0 0.0 Rain (# periods) 0.2 0.4 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.7 12.1 Temperature PM 850 mb (°C) 18.0 12.9 Stability at Atlanta (°C) 3.2 7.4 Geopotential height difference 700 mb at Atlanta (m) 7.4 12.0 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 0.6 0.7 Wind direction yesterday 700 mb at Atlanta (degrees) 27 326 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 3.3 4.5 Wind speed AM 850 mb at Atlanta (ms -1 ) 2.8 5.7 Wind speed PM 850 mb at Atlanta (ms -1 ) 4.9 4.7 Wind direction yesterday 850 mb at Atlanta (degrees) 34 342 Wind direction AM 850 mb at Atlanta (degrees) 225 333 Wind direction PM 850 mb at Atlanta (degrees) 207 326 Recirculation at Atlanta 0.2 0.1 Cloud average 1.6 1.5Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-163 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16k. Summary of Average Input Parameters for Each Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Memphis.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 4 Class 5
Bin 14 Bin 5 Bin 25 Bin 15 Bin 32 Bin 22
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 34.6 30.7 29.6 32.2 34.7 27.5 Yesterday's FM at Memphis (μg/m 3 ) 21.8 15.3 21.4 23.0 35.0 23.1 Yesterday's FM at Nashville (μg/m 3 ) 22.1 18.7 19.4 23.0 30.1 25.3 Yesterday's FM at St. Louis (μg/m 3 ) 21.2 18.4 19.7 19.0 31.5 24.7 Yesterday's FM at Little Rock (μg/m 3 ) 21.9 16.6 19.0 26.5 29.0 19.5 Surface Meteorological Parameters Max. surface temperature (°C) 31.0 28.3 23.4 33.4 28.8 24.5 Min. surface temperature (°C) 20.2 17.4 11.2 23.8 18.8 16.6 Relative humidity (%) 59.4 57.4 62.1 63.9 64/3 68.8 Surface wind speed (ms -1 ) 2.4 2.3 2.8 2.0 2.0 2.0 Surface wind direction (degrees) 157 117 180 180 174 360 Persistence 0.8 0.9 0.9 0.8 0.8 0.8 Sea level pressure (mb) 1020 1021 1022 1019 1019 1019 Rainfall (inches) 0.0 0.0 0.1 0.0 0.0 0.0 Rain (# periods) 0.2 0.4 0.4 0.7 0.2 0.3 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.4 12.5 11.2 17.9 14.8 13.1 Temperature PM 850 mb (°C) 16.2 13.7 11.8 18.7 15.4 13.7 Stability at Nashville (°C) 2.3 1.5 5.6 -0.3 1.9 0.3 Geopotential height difference 700 mb at Nashville (m) 5.0 8.0 -3.9 -78.3 -5.9 2.9 Wind speed yesterday 700 mb at Nashville (ms -1 ) 4.2 4.9 6.8 11.0 7.4 6.5 Wind speed yesterday 700 mb at Little Rock (ms -1 ) 5.7 5.1 6.1 5.8 7.6 7.0 Wind direction yesterday 700 mb at Nashville (degrees) 319 90 326 326 24 63 Wind direction yesterday 700 mb at Little Rock (degrees) 135 90 270 315 90 360 Wind speed yesterday 850 mb at Nashville (ms -1 ) 3.8 5.3 3.1 3.9 4.6 5.1 Wind speed yesterday 850 mb at Little Rock (ms -1 ) 4.6 5.4 4.7 2.9 5.3 4.4 Wind speed AM 850 mb at Nashville (ms -1 ) 4.8 3.7 8.0 4.9 4.6 4.8 Wind speed AM 850 mb at Little Rock (ms -1 ) 5.8 3.8 7.4 3.9 5.7 4.2 Wind speed PM 850 mb at Nashville (ms -1 ) 4.3 3.7 12.7 4.5 5.1 5.2 Wind speed PM 850 mb at Little Rock (ms -1 ) 5.2 4.2 7.7 2.2 6.1 5.2 Wind direction yesterday 850 mb at Nashville (degrees) 221 162 360 360 330 27 Wind direction yesterday 850 mb at Little Rock (degrees) 170 108 221 207 135 360 Wind direction AM 850 mb at Nashville (degrees) 262 270 243 292 292 117 Wind direction AM 850 mb at Little Rock (degrees) 196 153 233 270 204 326 Wind direction PM 850 mb at Nashville (degrees) 193 135 236 284 304 360 Wind direction PM 850 mb at Little Rock (degrees) 187 135 225 270 173 90 Cloud average 1.8 1.9 1.5 1.9 1.9 2.3Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-164 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16l. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Montgomery.
The ranges in PM2.5 for Categories 3 and 4 are 25-30 and ≥ 30 μ gm-3.

Class 3 Class 4
Bin 19 Bin 31 Bin 26 Bin 14
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 31.8 34.8 47.1 30.9 Yesterday's FM at Atlanta (μg/m 3 ) 25.4 33.6 35.7 32.9 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 19.3 22.7 23.0 22.4 Surface Meteorological Parameters Max. surface temperature (°C) 32.9 31.7 31.8 30.4 Min. surface temperature (°C) 21.0 20.3 18.4 21.0 Relative humidity (%) 71.3 66.2 65.3 75.6 Surface wind speed (ms -1 ) 0.9 2.7 0.8 1.0 Surface wind direction (degrees) 270 90 270 90 Persistence 0.6 0.9 0.7 0.6 Sea level pressure (mb) 1019 1020 1020 1017 Rainfall (inches) 0.2 0.0 0.0 0.1 Rain (# periods) 0.9 0.2 0.4 1.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 32.9 31.7 31.8 30.4 Temperature PM 850 mb (°C) 18.7 16.6 16.6 16.3 Stability at Birmingham (°C) 1.0 0.9 2.8 0.2 Geopotential height difference 700 mb at Birmingham (m) 0.2 6.1 -4.9 -5.3 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 6.8 5.3 5.1 7.6 Wind direction yesterday 700 mb at Birmingham (degrees) 270 180 326 45 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 7.1 5.8 3.6 4.7 Wind speed AM 850 mb at Birmingham (ms -1 ) 4.6 5.7 4.7 4.3 Wind speed PM 850 mb at Birmingham (ms -1 ) 6.4 4.3 4.0 2.2 Wind direction yesterday 850 mb at Birmingham (degrees) 360 270 333 326 Wind direction AM 850 mb at Birmingham (degrees) 256 180 284 284 Wind direction PM 850 mb at Birmingham (degrees) 27 207 346 270 Recirculation at Birmingham 0.0 0.2 0.2 0.6 Cloud average 1.6 1.8 1.8 2.2Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-165 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16m. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Nashville.
The ranges in PM2.5 for Categories 3 and 4 are 25-32.5 and ≥ 32.5 μ gm-3.

Class 3 Class 4
Bin 19 Bin 16 Bin 27 Bin 25 Bin 20
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 29.4 30.8 28.6 40.1 24.2 Yesterday's FM at Memphis (μg/m 3 ) 24.5 20.3 28.1 29.5 24.4 Yesterday's FM at Nashville (μg/m 3 ) 27.9 21.0 30.1 32.0 29.0 Yesterday's FM at Louisville (μg/m 3 ) 26.4 23.5 32.2 31.5 42.1 Yesterday's FM at Cincinnati (μg/m 3 ) 24.3 23.3 31.6 33.5 29.1 Yesterday's FM at Knoxville (μg/m 3 ) 21.5 23.3 24.5 36.3 20.6 Surface Meteorological Parameters Max. surface temperature (°C) 23.2 32.2 31.2 30.3 33.2 Min. surface temperature (°C) 12.2 20.4 20.8 18.1 21.4 Relative humidity (%) 69.5 66.1 61.6 64.8 67.0 Surface wind speed (ms -1 ) 1.5 1.7 2.8 1.3 1.4 Surface wind direction (degrees) 194 180 315 180 360 Persistence 0.7 0.7 0.9 0.7 0.7 Sea level pressure (mb) 1021 1020 1018 1022 1017 Rainfall (inches) 0.0 0.0 0.0 0.0 0.0 Rain (# periods) 0.3 0.4 0.1 0.2 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 10.5 16.7 16.8 15.8 19.8 Temperature PM 850 mb (°C) 11.8 17.9 16.8 16.4 20.8 Stability at Nashville (°C) 1.4 1.0 0.5 1.6 0.2 Geopotential height difference 700 mb at Nashville (m) 9.9 15.3 -9.8 -0.6 10.2 Wind speed yesterday 700 mb at Nashville (ms -1 ) 7.9 4.4 6.6 5.2 7.4 Wind direction yesterday 700 mb at Nashville (degrees) 328 315 333 90 27 Wind speed yesterday 850 mb at Nashville (ms -1 ) 4.9 3.9 4.8 4.3 4.6 Wind speed AM 850 mb at Nashville (ms -1 ) 5.4 6.1 6.6 5.6 6.0 Wind speed PM 850 mb at Nashville (ms -1 ) 5.1 5.3 5.9 5.0 4.5 Wind direction yesterday 850 mb at Nashville (degrees) 281 214 315 225 27 Wind direction AM 850 mb at Nashville (degrees) 301 261 329 243 360 Wind direction PM 850 mb at Nashville (degrees) 236 211 315 180 360 Recirculation at Nashville 0.1 0.1 0.1 0.2 0.2 Cloud average 1.6 1.8 1.5 1.9 1.6Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-166 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16n. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Raleigh.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 3 Class 4
Bin 22 Bin 23 Bin 9 Bin 28 Bin 30 Bin 26
PM 2.5

Parameters Yesterday's FM at Charlotte (μg/m 3 ) 19.7 23.6 20.3 31.0 29.3 32.4 Yesterday's FM at Richmond (μg/m 3 ) 18.7 16.7 19.0 31.0 27.0 26.6 Yesterday's FM at Raleigh (μg/m 3 ) 18.9 26.3 18.6 31.8 31.4 30.7 Yesterday's FM at Winston-Salem (μg/m 3 ) 20.7 25.4 22.4 31.2 30.6 27.2 Surface Meteorological Parameters Max. surface temperature (°C) 32.4 23.1 24.8 33.0 34.2 25.1 Min. surface temperature (°C) 18.9 11.8 13.9 20.5 21.6 12.0 Relative humidity (%) 67.8 76.1 73.7 69.9 71.6 71.4 Surface wind speed (ms -1 ) 1.3 1.9 1.3 1.7 2.2 2.0 Surface wind direction (degrees) 211 243 124 239 211 27 Persistence 0.7 0.8 0.8 0.8 0.7 0.8 Sea level pressure (mb) 1019 1020 1022 1018 1017 1022 Rainfall (inches) 0.2 0.1 0.1 0.0 0.0 0.0 Rain (# periods) 0.4 0.7 0.5 0.2 0.7 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 16.5 11.7 11.8 17.1 18.6 12.3 Temperature PM 850 mb (°C) 18.1 10.9 13.3 18.0 19.0 12.4 Stability at Greensboro (°C) 1.0 1.3 -0.3 0.4 0.9 2.1 Geopotential height difference 700 mb at Greensboro (m) 2.1 -23.6 28.4 -1.6 -8.1 6.0 Wind speed yesterday 700 mb at Greensboro (ms -1 ) 7.9 11.1 10.4 6.4 8.7 9.4 Wind direction yesterday 700 mb at Greensboro (degrees) 7 276 309 306 270 346 Wind speed yesterday 850 mb at Greensboro (ms -1 ) 4.3 6.9 6.3 5.0 5.0 5.5 Wind speed AM 850 mb at Greensboro (ms -1 ) 3.8 9.9 6.1 3.9 9.8 6.7 Wind speed PM 850 mb at Greensboro (ms -1 ) 3.6 7.3 5.6 4.3 9.1 6.0 Wind direction yesterday 850 mb at Greensboro (degrees) 339 236 297 294 261 360 Wind direction AM 850 mb at Greensboro (degrees) 342 256 270 302 286 14 Wind direction PM 850 mb at Greensboro (degrees) 270 259 270 277 262 326 Recirculation at Greensboro 0.2 0.1 0.2 0.1 0.0 0.2 Cloud average 1.7 1.8 1.8 1.5 1.7 1.4Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-167 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16o. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Richmond.
The ranges in PM2.5 for Categories 3 and 4 are 25-30 and ≥ 30 μ gm-3. Class 3 Class 4 Bin 8 Bin 12 Bin 16 Bin 24 Bin 33 Bin 32
PM 2.5

Parameters Yesterday's FM at Richmond (μg/m 3 ) 13.1 21.7 21.9 26.6 37.2 22.7 Yesterday's FM at Winston-Salem (μg/m 3 ) 16.0 21.9 22.6 16.3 33.5 25.7 Yesterday's FM at Washington, D.C. (μg/m 3 ) 15.5 20.8 21.7 37.9 42.2 28.0 Surface Meteorological Parameters Max. surface temperature (°C) 30.3 26.3 22.3 25.3 34.8 33.6 Min. surface temperature (°C) 19.0 16.7 10.9 14.5 22.6 20.6 Relative humidity (%) 70.4 80.2 72.3 78.6 68.8 68.1 Surface wind speed (ms -1 ) 1.6 2.2 1.2 1.9 2.3 1.9 Surface wind direction (degrees) 326 146 104 144 216 198 Persistence 0.7 0.8 0.6 0.8 0.7 0.8 Sea level pressure (mb) 1018 1020 1020 1020 1018 1020 Rainfall (inches) 0.2 0.0 0.1 0.0 0.1 0.0 Rain (# periods) 0.9 0.5 0.9 0.7 0.7 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14.9 12.5 9.1 12.5 18.3 18.1 Temperature PM 850 mb (°C) 16.4 13.8 10.4 13.6 19.3 18.1 Stability at Dulles (°C) 1.4 0.8 1.6 2.3 1.1 3.9 Geopotential height difference 700 mb at Dulles (m) 13.3 3.1 13.8 -4.8 12.0 5.6 Wind speed yesterday 700 mb at Roanoke (ms -1 ) 10.2 8.0 11.5 7.4 6.0 6.3 Wind speed yesterday 700 mb at Dulles (ms -1 ) 9.7 8.1 13.7 9.9 8.2 8.0 Wind direction yesterday 700 mb at Roanoke (degrees) 307 270 270 288 315 360 Wind direction yesterday 700 mb at Dulles (degrees) 292 309 270 275 300 6 Wind speed yesterday 850 mb at Roanoke (ms -1 ) 5.0 4.6 6.7 5.0 4.9 3.7 Wind speed yesterday 850 mb at Dulles (ms -1 ) 7.5 3.9 10.2 6.2 6.7 6.1 Wind speed AM 850 mb at Roanoke (ms -1 ) 6.0 6.8 7.3 6.9 8.2 7.7 Wind speed AM 850 mb at Dulles (ms -1 ) 8.9 5.5 8.6 7.4 7.0 6.4 Wind speed PM 850 mb at Roanoke (ms -1 ) 5.3 4.9 7.5 7.4 5.9 6.5 Wind speed PM 850 mb at Dulles (ms -1 ) 7.7 7.0 8.0 8.2 7.7 8.2 Wind direction yesterday 850 mb at Roanoke (degrees) 323 270 270 262 276 301 Wind direction yesterday 850 mb at Dulles (degrees) 323 270 270 275 291 326 Wind direction AM 850 mb at Roanoke (degrees) 360 259 270 270 275 225 Wind direction AM 850 mb at Dulles (degrees) 351 309 278 270 290 278 Wind direction PM 850 mb at Roanoke (degrees) 346 198 214 254 270 252 Wind direction PM 850 mb at Dulles (degrees) 338 217 270 259 270 270 Cloud average 1.9 1.9 2.0 1.9 1.8 1.7Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-168 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-16p. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for STN Site Savannah.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-27.5 and ≥ 27.5 μ gm-3.

Class 3 Class 4
Bin 17 Bin 5 Bin 25
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 23.8 30.4 31.5 Yesterday's FM at Charleston (μg/m 3 ) 18.4 11.2 26.1 Surface Meteorological Parameters Max. surface temperature (°C) 25.9 29.6 30.9 Min. surface temperature (°C) 12.7 6.0 19.3 Relative humidity (%) 71.7 67.2 71.3 Surface wind speed (ms -1 ) 0.9 0.8 1.3 Surface wind direction (degrees) 45 236 207 Persistence 0.7 0.4 0.7 Sea level pressure (mb) 1022 1017 1019 Rainfall (inches) 0.0 0.0 0.0 Rain (# periods) 0.1 0.4 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 11.0 12.9 15.8 Temperature PM 850 mb (°C) 12.0 14.4 16.4 Stability at Charleston (°C) 1.8 1.1 -1.4 Geopotential height difference 700 mb at Charleston (m) 5.8 17.1 -0.9 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 8.6 9.1 8.6 Wind speed yesterday 700 mb at Charleston (ms -1 ) 7.3 13.3 7.6 Wind direction yesterday 700 mb at Atlanta (degrees) 315 360 338 Wind direction yesterday 700 mb at Charleston (degrees) 315 315 342 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 5.1 7.4 3.8 Wind speed yesterday 850 mb at Charleston (ms -1 ) 5.8 8.6 5.8 Wind speed AM 850 mb at Atlanta (ms -1 ) 4.8 6.7 7.1 Wind speed AM 850 mb at Charleston (ms -1 ) 4.7 8.0 6.9 Wind speed PM 850 mb at Atlanta (ms -1 ) 5.6 5.8 5.3 Wind speed PM 850 mb at Charleston (ms -1 ) 6.2 6.1 6.0 Wind direction yesterday 850 mb at Atlanta (degrees) 288 333 304 Wind direction yesterday 850 mb at Charleston (degrees) 346 288 321 Wind direction AM 850 mb at Atlanta (degrees) 288 304 18 Wind direction AM 850 mb at Charleston (degrees) 342 284 326 Wind direction PM 850 mb at Atlanta (degrees) 284 326 304 Wind direction PM 850 mb at Charleston (degrees) 333 304 349 Cloud 1.9 2.0 1.8



### For Charlotte, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 22.5 to 30 and greater than or equal to 30 μ gm -3 

### , respectively. There are four Category 3 and one Category 4 key bins. All of the key high PM 2.5 

### bins are characterized by low surface wind speeds, and moderate relative humidity. Average temperatures and, to some extent, humidity vary relative among the bins. Bins 15 and 12 (two of the Category 3 bins) have lower temperatures, typical of spring orCharacterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-169 VISTAS Meteorological Characterization

06-046 December 8, 2006 

### fall. Prior day PM 2.5 

### values at the potential upwind sites are consistently highest for Bin 26, the Category 4 bin. With the exception of Atlanta, the regional concentrations vary consistently among the bins. Average surface wind direction is southwesterly for four of the five key bins, and southeasterly for the remaining key bin (Bin 12). Stability is greatest, on average, for the cooler days in Bin 15. Upper-air wind speeds and directions vary only slightly among the bins. Morning and evening 850 mb wind directions are northwesterly for all bins. The higher regionalconcentrations are the most distinguishing feature of the Category 4 bin. Thus, regional buildup/transport appears to drive high PM 2.5 

### in Charlotte.
For Chattanooga, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 25 to 32.5 and greater than or equal to 32.5 μ gm -3 

### , respectively. There are three Category 3 and one Category 4 bins that meet the criteria for key bins. All of the key high PM 2.5 

### bins are characterized by very low surface wind speeds and moderate relative humidity. Average temperature ranges from moderate to high and varies among the bins. Bins 28 (the Category 4 bin) has the lowest temperatures, both near the surface and aloft. Prior day PM 2.5 

### values for at the potential upwind sites are consistently highest for Bin 28, the Category 4 bin. Average surface wind direction is southwesterly for the three key Category 3 bins, and southerly for the Category 4 bin. Upper-air wind directions vary considerably among the bi ns. Southwesterly winds over Nashville and easterly followed by southwesterly winds aloft ov er Atlanta characterize the Bin 28 (Category 4). Average conditions for days within Bin 28 are sim ilar in many respects to those for Bin 19, cooler temperatures and much higher regional concentrations appear to influence the higher PM 2.5 

### concentrations for Bin 28.

For Louisville, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 27.5 to 37.5 and greater than or equal to 37.5 μ gm -3 

### , respectively. There are three Category 3 and three Category 4 bins that meet the criteria for key bins. The Category 4 bins have lower average wind speeds and a greater tendency for easterly wind components. The Category 4 bins are characterized by a range of temperature, humidity, and wind direction. All are associated with low wind speeds and high prior-day PM 2.5 

### concentrations at potential upwind sites. Bin 29 has the lowest average temperature and the highest average relative humidity value. This bin is also characterized by southeasterly surface winds an d northerly to easterly winds aloft. Bin 24 is distinguished by southwesterly to westerly winds both near the surface and aloft. Bin 25 is characterized by very high average temperatures and low relative humidity. Winds are from the northeast near the surface and from the northwest to the southeast aloft. Winds speeds aloft are low, compared to other bins. For Louisville, CART appears to have identified three distinct high PM 2.5 

### concentration regimes.

For Macon, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 25 to 30 and greater than or equal to 30 μ gm -3 

### , respectively. There is one key bin for each category. Both are characterized, on average, by very low surface wind speeds, moderate relative humidity, and prior-day PM 2.5 

### concentrations of about 30 μ gm -3 

### in the Atlanta area. Bin 19 (Category 3) has higher temperatures and lower wind speeds aloft. Surface wind directions are from the southeast, and upper air wind directions are from the southwest. Bin 14 (Category 4) has cooler temperatures and greater stability. Surface wind directions are from the southwest, and upper air wind directions are from the northwest. Local conditions combined with a greater potential for pollutant transport from Atlanta appear to drive the higher PM 2.5 

### concentrations for Bin 14.Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis



### Figure 3-8 shows the average composition for all key PM 2.5 

### bins for each of the STN sites. Note that for some sites and bins, there were insufficient speciated data to compute the bin averages. These are marked with an asterisk.

Figure 3-8a. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Birmingham.

Birmingham Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

4 (417) 8 (193) 24 (97) 2 (38) 25 (27) 6 (24) 11 (45) 26 (7) 19 (23) 10 (11)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-8b. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Charlotte.

Charlotte Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (739) 21 (121) 20 (73) 6 (83) 8 (15) 31 (27) 15 (18) 12 (14) 18 (14) 26 (31)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO4
OM
SO4

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06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8c. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Chattanooga.

Chattanooga Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

7 (193) 2 (69) 12 (48) 6 (24) 17 (21) 10 (15) 22 (11) 19 (7) 21 (7) 28 (10)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-8d. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Greenville-Spartanburg.

Greenville-Spartanburg Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (711) 15 (121) 2 (62) 8 (63) 6 (71) 3 (23) 11 (9) 20 (28) 25 (11) 22 (10) 32 (4) 21 (4) 30 (4)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* * * Greenville-Spartanburg Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (711) 15 (121) 2 (62) 8 (63) 6 (71) 3 (23) 11 (9) 20 (28) 25 (11) 22 (10) 32 (4) 21 (4) 30 (4)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* * *

* No speciated data for this bin

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### 3-171 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8e. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Hickory.

Hickory Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

2 (272) 8 (35) 13 (21) 12 (18) 6 (10) 18 (6) 29 (8) 27 (6) 22 (11) 17 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* * Hickory Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

2 (272) 8 (35) 13 (21) 12 (18) 6 (10) 18 (6) 29 (8) 27 (6) 22 (11) 17 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* *

* No speciated data for this bin
Figure 3-8f. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Huntington-Ashland.

Huntington-Ashland Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

8 (243) 7 (40) 5 (22) 29 (20) 28 (20) 1 (14) 6 (11) 13 (10) 14 (10) 12 (8) 23 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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### 3-172 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8g. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Jackson.

Jackson Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (175) 7 (38) 20 (23) 15 (27) 11 (18) 5 (15) 30 (7) 34 (8) 22 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* Jackson Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (175) 7 (38) 20 (23) 15 (27) 11 (18) 5 (15) 30 (7) 34 (8) 22 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

*

* No speciated data for this bin
Figure 3-8h. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Kingsport-Bristol.

Kingsport-Bristol Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (254) 19 (43) 20 (23) 16 (22) 9 (16) 5 (6) 23 (10) 27 (12) 3 (9) 24 (7) 32 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8i. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Louisville.

Louisville Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (724) 3 (153) 10 (104) 12 (79) 2 (31) 4 (28) 15 (12) 30 (13) 17 (15) 24 (26) 25 (7) 29 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* * Louisville Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (724) 3 (153) 10 (104) 12 (79) 2 (31) 4 (28) 15 (12) 30 (13) 17 (15) 24 (26) 25 (7) 29 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* *

* No speciated data for this bin
Figure 3-8j. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Macon.

Macon Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (158) 11 (49) 29 (28) 5 (29) 10 (27) 28 (14) 25 (12) 19 (5) 14 (14)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8k. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Memphis.

Memphis Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (645) 6 (125) 10 (111) 12 (35) 9 (26) 27 (23) 14 (37) 5 (8) 25 (8) 15 (9) 32 (34) 22 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* Memphis Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (645) 6 (125) 10 (111) 12 (35) 9 (26) 27 (23) 14 (37) 5 (8) 25 (8) 15 (9) 32 (34) 22 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

*

* No speciated data for this bin
Figure 3-8l. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Montgomery.

Montgomery Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (242) 5 (69) 2 (19) 13 (18) 30 (11) 18 (13) 19 (7) 31 (5) 26 (11) 14 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

ICF International 

### 3-175 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8m. Average Elemental Carbon (EC), Nitr ate (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Nashville.

Nashville Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

3 (556) 7 (337) 12 (90) 11 (64) 5 (40) 15 (22) 19 (22) 16 (10) 27 (8) 25 (21) 20 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* Nashville Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

3 (556) 7 (337) 12 (90) 11 (64) 5 (40) 15 (22) 19 (22) 16 (10) 27 (8) 25 (21) 20 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

*

* No speciated data for this bin
Figure 3-8n. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Raleigh.

Raleigh Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (615) 4 (239) 2 (144) 13 (57) 24 (17) 16 (19) 22 (20) 23 (11) 9 (12) 28 (20) 30 (10) 26 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* * Raleigh Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (615) 4 (239) 2 (144) 13 (57) 24 (17) 16 (19) 22 (20) 23 (11) 9 (12) 28 (20) 30 (10) 26 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* *

* No speciated data for this bin

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### 3-176 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

Figure 3-8o. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Richmond.

Richmond Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

1 (640) 2 (133) 6 (66) 9 (69) 7 (46) 3 (17) 19 (21) 8 (7) 12 (12) 16 (9) 24 (16) 33 (18) 32 (10)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

* No speciated data for this bin
Figure 3-8p. Average Elemental Carbon (EC), Nitrat e ( NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: STN Site Savannah.

Savannah Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

9 (217) 8 (61) 14 (55) 18 (8) 11 (6) 3 (6) 17 (8) 5 (5) 25 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM SO$

* Savannah Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

9 (217) 8 (61) 14 (55) 18 (8) 11 (6) 3 (6) 17 (8) 5 (5) 25 (9)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM SO$

*

* No speciated data for this bin


### The STN compositional charts show a much larger proportional contribution from organic matter compared to those for the IMPROVE sites, especially for the higher PM 2.5 

### bins. This is in part due to differences between the IMPROVE and STN measurement techniques for organic carbon. Studies (e.g., EPA, 2004) have estimated the STN measurements to be as much as 30 percent higher. Another reason for the higher organic contribution is that the STN sites are located in urban areas, which have higher organic carbon emissions.

The relative contributions of the PM 2.5 

### components vary by bin for each of the sites. The high PM 2.5 

### concentration bins are distinguished from the lower concentration bins by higher sulfate and organic matter concentrations. With the higher values for organics, the dominant species

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### 3-177 VISTAS Meteorological Characterization

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### 3-178 VISTAS Meteorological Characterization

06-046 December 8, 2006 

### varies by bin, much more so than for the IMPROVE sites. Again, these variations are attributable to differences in meteorology as well as regional pollutant transport.
Consider the two key high PM 2.5 

### bins for Macon (Bins 19 and 14). We noted earlier, that more stable conditions and a greater potential for pollutant transport from Atlanta appear to drive the higher PM 2.5 

### concentrations for Bin 14. This is manifested (Figure 3-8j) by higher average sulfate concentrations for this bin, compared to Bin 19. On average, Bin 19 is dominated by organic matter, while Bin 14 has a greater proportion of sulfate.
Table 3-17 summarizes the characteristics for key Category 3 and 4 bins for the SEARCH monitoring sites.

Table 3-17a. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Atlanta (Jefferson St.).
The ranges in PM2.5 for Categories 3 and 4 are 27.5-35 and ≥ 35 μ gm-3.

Class 3 Class 4 Bin 28 Bin 31 Bin 21 Bin 19 Bin 23 Bin 26
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 31.3 30.9 33.4 37.7 34.9 43.4 Yesterday's FM at Birmingham (μg/m 3 ) 34.1 35.9 35.5 39.2 34.3 44.0 Surface Meteorological Parameters Max. surface temperature (°C) 31.7 26.2 27.9 29.8 27.23 28.5 Min. surface temperature (°C) 21.4 18.0 16.1 18.6 14.5 15.0 Relative humidity (%) 74.2 70.7 66.0 69.9 61.8 65.1 Surface wind speed (ms -1 ) 0.7 1.9 0.6 0.8 0.6 0.5 Surface wind direction (degrees) 248 117 207 254 304 63 Persistence 0.6 0.9 0.6 0.8 0.6 0.6 Station pressure (mb) 987 990 990 988 989 991 Rainfall (inches) 0.3 0.1 0 0.0 0.0 0 Rain (# periods) 1.7 0.7 0 0.1 0.1 0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 17.1 14.7 13.5 15.4 13.6 14.1 Temperature PM 850 mb (°C) 17.6 13.8 14.9 16.3 15.7 14.8 Stability at Atlanta (°C) 2.7 2.7 6.1 4.6 6.4 6.8 Geopotential height difference 700 mb at Atlanta (m) -4.6 27.5 -10.8 6.4 -3.3 37.3 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 6.4 5.5 5.4 5.6 9.9 3.6 Wind direction yesterday 700 mb at Atlanta (degrees) 326 259 31 9 326 0 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 3.6 5.2 5.2 2.4 6.8 4.9 Wind speed AM 850 mb at Atlanta (ms -1 ) 5.3 6.8 3.4 3.5 7.1 3.5 Wind speed PM 850 mb at Atlanta (ms -1 ) 4.7 6.6 3.4 6.7 4.8 3.7 Wind direction yesterday 850 mb at Atlanta (degrees) 281 180 n/a 307 326 315 Wind direction AM 850 mb at Atlanta (degrees) 306 166 90 288 315 45 Wind direction PM 850 mb at Atlanta (degrees) 225 146 135 225 307 76 Recirculation at Atlanta 0.1 0.1 0.2 0.4 0 0.2 Cloud average 2.1 2.1 1.5 1.6 1.6 1.2Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-179 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17b. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Yorkville.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 3 Class 4 Bin 18 Bin 28 Bin 16 Bin 22 Bin 29 Bin 15
PM 2.5

Parameters Yesterday's FM at Atlanta (μg/m 3 ) 25.5 35.5 26.3 38.0 39.9 27.1 Yesterday's FM at Birmingham (μg/m 3 ) 28.3 38.3 29.9 43.9 35.3 30.7 Yesterday's FM at Yorkville (μg/m 3 ) 22.2 28.7 22.7 35.4 31.8 21.5 Surface Meteorological Parameters Max. surface temperature (°C) 28.5 28.2 23.2 28.6 26.6 28.6 Min. surface temperature (°C) 18.1 17.6 18.1 18.4 17.2 18.6 Relative humidity (%) 71.7 66.7 92.6 72.8 75.0 71.3 Surface wind speed (ms -1 ) 2.0 2.7 1.7 1.2 2.6 1.8 Surface wind direction (degrees) 99 243 180 243 90 108 Persistence 0.8 0.9 0.6 0.7 1.0 0.7 Station pressure (mb) 975 972 972 974 978 974 Rainfall (inches) 0.1 0.1 0.1 0.0 0.1 0.1 Rain (# periods) 0.6 0.5 2.0 0.1 0.9 1.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.0 15.2 13.9 15.3 13.4 15.3 Temperature PM 850 mb (°C) 14.3 16.4 15.3 16.5 13.0 16.6 Stability at Atlanta (°C) 2.5 6.6 -1.0 4.0 4.0 2.2 Geopotential height difference 700 mb at Atlanta (m) -6.9 -6 -0.9 4.8 5.4 -1.6 Wind speed yesterday 700 mb at Atlanta (ms -1 ) 5.1 4.9 7.4 5.7 4.5 6.0 Wind direction yesterday 700 mb at Atlanta (degrees) 48 292 360 23 333 27 Wind speed yesterday 850 mb at Atlanta (ms -1 ) 4.2 3.4 4.3 3.9 4.5 3.8 Wind speed AM 850 mb at Atlanta (ms -1 ) 6.1 5.9 5.3 4.0 5.9 4.2 Wind speed PM 850 mb at Atlanta (ms -1 ) 4.4 7.6 5.2 4.0 5.9 4.2 Wind direction yesterday 850 mb at Atlanta (degrees) 98 249 315 22 117 297 Wind direction AM 850 mb at Atlanta (degrees) 90 277 225 342 124 90 Wind direction PM 850 mb at Atlanta (degrees) 112 254 0 56 124 135 Recirculation at Atlanta 0.2 0.2 0.3 0.4 0 0.2 Cloud average 1.7 1.7 2.5 1.7 2.0 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-180 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17c. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Birmingham.
The ranges in PM2.5 for Categories 3 and 4 are 30-37.5 and ≥ 37.5 μ gm-3.

Class 3 Class 4 Bin 10 Bin 14 Bin 25 Bin 20 Bin 24
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 24.7 35.6 51.1 33.1 35.8 Yesterday's FM at Atlanta (μg/m 3 ) 21.1 27.8 39.3 23.5 25.5 Yesterday's FM at Memphis (μg/m 3 ) 18.8 21.9 27.8 18.2 20.8 Yesterday's FM at Nashville (μg/m 3 ) 16.8 21.2 28.9 18.7 17.9 Surface Meteorological Parameters Max. surface temperature (°C) 28.6 28.5 28.7 23.7 30.4 Min. surface temperature (°C) 12.8 15.8 14.0 10.2 15.9 Relative humidity (%) 60.1 66.5 58.6 64.8 58.4 Surface wind speed (ms -1 ) 0.6 0.5 0.5 0.5 0.7 Surface wind direction (degrees) 360 342 344 27 180 Persistence 0.6 0.5 0.7 0.6 0.7 Station pressure (mb) 998 998 1000 1002 1000 Rainfall (inches) 0.0 0.1 0.0 0.0 0.0 Rain (# periods) 0.3 0.6 0.0 0.2 0.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 12.9 13.1 13.5 11.3 15.0 Temperature PM 850 mb (°C) 13.7 14.5 14.1 12.3 15.9 Stability at Birmingham (°C) 4.0 3.1 4.6 2.9 4.3 Geopotential height difference 700 mb at Birmingham (m) 6.6 -2.9 0.8 -14.7 30.1 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 6.5 5.2 4.7 9.0 6.8 Wind direction yesterday 700 mb at Birmingham (degrees) 310 292 354 63 338 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 4.2 2.7 2.9 7.0 2.8 Wind speed AM 850 mb at Birmingham (ms -1 ) 5.1 4.9 3.7 6.1 4.2 Wind speed PM 850 mb at Birmingham (ms -1 ) 4.3 4.8 2.9 4.9 3.7 Wind direction yesterday 850 mb at Birmingham (degrees) 360 254 37 27 90 Wind direction AM 850 mb at Birmingham (degrees) 270 243 270 180 270 Wind direction PM 850 mb at Birmingham (degrees) 34 220 360 207 243 Recirculation at Birmingham 0.2 0.3 0.5 0.0 0.4 Cloud average 1.3 1.7 1.4 1.6 1.6Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-181 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17d. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SE ARCH Site Centreville.
The ranges in PM2.5 for Categories 3 and 4 are 22.5-30 and ≥ 30 μ gm-3.

Class 3 Class 4 Bin 16 Bin 20 Bin 19 Bin 28 Bin 18 Bin 21
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 34.6 33.6 32.8 51.5 25.3 38.6 Yesterday's FM at Atlanta (μg/m 3 ) 28.1 33.1 31.1 38.1 18.5 30.0 Yesterday's FM at Centreville (μg/m 3 ) 24.7 24.6 26.7 38.3 24.3 27.9 Surface Meteorological Parameters Max. surface temperature (°C) 31.2 31.7 32.9 31.0 25.4 35.4 Min. surface temperature (°C) 20.4 20.3 22.8 19.8 13.5 23.7 Relative humidity (%) 70.8 21.9 70.0 67.6 68.0 71.6 Surface wind speed (ms -1 ) 1.4 0.9 3.0 1.0 1.2 1.0 Surface wind direction (degrees) 330 110 304 349 329 153 Persistence 0.7 0.6 1.0 0.7 0.6 0.6 Station pressure (mb) 1003 1004 997 1005 1003 1005 Rainfall (inches) 0.0 0.0 0.0 0.1 0.1 0.0 Rain (# periods) 0.3 0.4 0.2 0.1 0.6 0.2 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.5 15.8 18.2 15.2 12.4 18.0 Temperature PM 850 mb (°C) 16.2 17.1 17.9 15.9 11.3 20.1 Stability at Birmingham (°C) 1.6 2 -1.4 2.6 1.7 3.4 Geopotential height difference 700 mb at Birmingham (m) -4.1 -0.2 -19.8 -0.3 15.1 10.3 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 5.9 5.6 9.3 4.9 12.3 5.2 Wind direction yesterday 700 mb at Birmingham (degrees) 342 56 27 6 297 360 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 4.6 3.6 5.6 3.7 6.1 2.6 Wind speed AM 850 mb at Birmingham (ms -1 ) 5.0 3.3 11.0 3.5 8.2 4.6 Wind speed PM 850 mb at Birmingham (ms -1 ) 4.5 2.6 7.1 2.9 4.7 2.7 Wind direction yesterday 850 mb at Birmingham (degrees) 360 27 14 23 11 n/a Wind direction AM 850 mb at Birmingham (degrees) 309 202 360 243 270 315 Wind direction PM 850 mb at Birmingham (degrees) 356 117 346 45 360 270 Recirculation at Birmingham 0.3 0.4 0 0.4 0 0.3 Cloud average 1.8 1.6 1.6 1.9 1.8 1.7Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-182 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17e. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Pensacola. The ranges in PM2.5 for Categories 3 and 4 are 22.5-27.5 and ≥ 27.5 μ gm-3.

Class 3 Class 4
Bin 22 Bin 31 Bin 19 Bin 27 Bin 18
PM 2.5

Parameters Yesterday's FM at Gulfport (μg/m 3 ) 19.4 24.2 18.2 25.0 16.9 Yesterday's FM at Pensacola (μg/m 3 ) 22.7 30.8 19.5 30.7 20.1 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 21.3 26.7 18.7 25.3 19.1 Surface Meteorological Parameters Max. surface temperature (°C) 25.2 24.9 25.3 28.0 24.2 Min. surface temperature (°C) 13.1 16.1 14.6 18.7 10.6 Relative humidity (%) 70.4 85.8 73.5 74.1 64.1 Surface wind speed (ms -1 ) 1.6 0.6 0.5 0.7 0.6 Surface wind direction (degrees) 90 72 153 169 360 Persistence 0.9 0.7 0.4 0.6 0.7 Station pressure (mb) 1019 1019 1022 1018 1024 Rainfall (inches) 0.0 0.1 0.0 0.0 0.0 Rain (# periods) 0.0 0.7 0.1 0.2 0.0 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 11.8 14.0 12.5 14.3 10.4 Temperature PM 850 mb (°C) 12.0 14.0 13.0 14.8 11.3 Stability at Tallahassee (°C) 2.3 1.9 2.4 1.5 6.2 Geopotential height difference 700 mb at Tallahassee (m) -7.5 11 23.1 0.6 -2.8 Wind speed yesterday 700 mb at Slidell (ms -1 ) 8.0 6.4 5.7 4.7 7.5 Wind speed yesterday 700 mb at Tallahassee (ms -1 ) 7.8 6.7 9.1 7.2 7.5 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 8.9 9.8 9.9 6.8 10.2 Wind direction yesterday 700 mb at Slidell (degrees) 90 270 297 328 315 Wind direction yesterday 700 mb at Tallahassee (degrees) 315 90 338 309 288 Wind direction yesterday 700 mb at Birmingham (degrees) 284 292 323 310 288 Wind speed yesterday 850 mb at Slidell (ms -1 ) 7.7 5.8 5.1 3.9 4.6 Wind speed yesterday 850 mb at Tallahassee (ms -1 ) 5.0 5.4 3.0 4.6 5.7 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 6.4 6.0 5.3 4.2 6.1 Wind speed AM 850 mb at Slidell (ms -1 ) 8.1 5.9 3.5 4.3 4.8 Wind speed AM 850 mb at Tallahassee (ms -1 ) 7.0 5.6 4.2 4.8 4.3 Wind speed AM 850 mb at Birmingham (ms -1 ) 8.5 7.1 5.9 4.1 6.1 Wind speed PM 850 mb at Slidell (ms -1 ) 8.1 4.9 4.0 4.3 5.1 Wind speed PM 850 mb at Tallahassee (ms -1 ) 7.2 6.1 4.0 5.6 4.5 Wind speed PM 850 mb at Birmingham (ms -1 ) 8.4 8.0 5.4 4.6 5.0 Wind direction yesterday 850 mb at Slidell (degrees) 360 180 346 360 333 Wind direction yesterday 850 mb at Tallahassee (degrees) 360 360 360 339 360 Wind direction yesterday 850 mb at Birmingham (degrees) 270 207 304 342 315 Wind direction AM 850 mb at Slidell (degrees) 207 194 207 214 342 Wind direction AM 850 mb at Tallahassee (degrees) 270 207 333 270 288 Wind direction AM 850 mb at Birmingham (degrees) 284 214 315 282 360 Wind direction PM 850 mb at Slidell (degrees) 297 198 360 22 360 Wind direction PM 850 mb at Tallahassee (degrees) 45 270 63 328 342 Wind direction PM 850 mb at Birmingham (degrees) 270 225 315 270 333 Cloud average 1.4 1.9 1.3 1.8 1.5Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-183 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17f. Summary of Average Input Parame ters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Outlying Landing Field (OLF). The ranges in PM2.5 for Categories 3 and 4 are 20-27.5 and ≥ 27.5 μ gm-3.

Class 3 Class 4
Bin 25 Bin 13 Bin 28
PM 2.5

Parameters Yesterday's FM at Gulfport (μg/m 3 ) 19.9 17.2 28.3 Yesterday's FM at Pensacola (μg/m 3 ) 23.9 21.4 31.5 Yesterday's FM at Outer Landing Field (μg/m 3 ) 21.1 16.2 33.8 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 21.9 20.3 27.0 Surface Meteorological Parameters Max. surface temperature (°C) 31.0 25.3 30.6 Min. surface temperature (°C) 18.5 11.0 18.9 Relative humidity (%) 67.5 59.1 73.3 Surface wind speed (ms -1 ) 1.6 1.1 1.0 Surface wind direction (degrees) 270 342 286 Persistence 0.7 0.6 0.6 Station pressure (mb) 1014 1016 1013 Rainfall (inches) 0.0 0.0 0.0 Rain (# periods) 0.2 0.1 0.4 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 15.4 11.7 15.6 Temperature PM 850 mb (°C) 16.3 12.0 16.0 Stability at Tallahassee (°C) 1.2 3.9 -0.4 Geopotential height difference 700 mb at Tallahassee (m) 3.1 1.6 5.3 Wind speed yesterday 700 mb at Slidell (ms -1 ) 4.8 6.1 4.9 Wind speed yesterday 700 mb at Tallahassee (ms -1 ) 7.5 8.4 6.9 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 7.8 7.5 5.8 Wind direction yesterday 700 mb at Slidell (degrees) 4 360 330 Wind direction yesterday 700 mb at Tallahassee (degrees) 336 342 311 Wind direction yesterday 700 mb at Birmingham (degrees) 315 352 319 Wind speed yesterday 850 mb at Slidell (ms -1 ) 4.8 7.0 4.0 Wind speed yesterday 850 mb at Tallahassee (ms -1 ) 5.5 4.1 4.6 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 6.0 5.4 5.6 Wind speed AM 850 mb at Slidell (ms -1 ) 4.7 5.8 3.9 Wind speed AM 850 mb at Tallahassee (ms -1 ) 5.3 6.0 5.2 Wind speed AM 850 mb at Birmingham (ms -1 ) 6.7 6.2 3.4 Wind speed PM 850 mb at Slidell (ms -1 ) 5.7 5.9 3.6 Wind speed PM 850 mb at Tallahassee (ms -1 ) 5.4 5.8 5.3 Wind speed PM 850 mb at Birmingham (ms -1 ) 6.0 5.1 3.0 Wind direction yesterday 850 mb at Slidell (degrees) 25 11 22 Wind direction yesterday 850 mb at Tallahassee (degrees) 352 360 325 Wind direction yesterday 850 mb at Birmingham (degrees) 320 352 333 Wind direction AM 850 mb at Slidell (degrees) 180 90 135 Wind direction AM 850 mb at Tallahassee (degrees) 319 346 243 Wind direction AM 850 mb at Birmingham (degrees) 270 326 279 Wind direction PM 850 mb at Slidell (degrees) 8 63 48 Wind direction PM 850 mb at Tallahassee (degrees) 347 34 352 Wind direction PM 850 mb at Birmingham (degrees) 320 360 225 Cloud average 1.6 1.1 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

ICF International 

### 3-184 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17g. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Gulfport.
The ranges in PM2.5 for Categories 3 and 4 are 20-25 and ≥ 25 μ gm-3.

Class 3 Class 4
Bin 29 Bin 12 Bin 10 Bin 30 Bin 16
PM 2.5

Parameters Yesterday's FM at Gulfport (μg/m 3 ) 24.3 25.5 17.7 28.1 16.7 Yesterday's FM at Pensacola (μg/m 3 ) 20.0 18.0 21.7 29.9 16.9 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 26.1 18.3 18.1 28.4 22.1 Surface Meteorological Parameters Max. surface temperature (°C) 26.1 23.4 31.7 29.4 27.4 Min. surface temperature (°C) 6.1 9.6 21.3 19.4 16.7 Relative humidity (%) 77.9 69.7 73.9 73.3 67.9 Surface wind speed (ms -1 ) 1.4 1.0 1.2 1.0 0.7 Surface wind direction (degrees) 158 191 194 220 225 Persistence 0.7 0.5 0.6 0.5 0.4 Station pressure (mb) 1018 1019 1017 1017 1018 Rainfall (inches) 0.1 0.0 0.0 0.0 0.0 Rain (# periods) 0.5 0.1 0.3 0.3 0.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 12.5 11.1 16.2 14.2 13.2 Temperature PM 850 mb (°C) 12.5 11.5 16.7 14.9 14.0 Stability at Slidell (°C) 1.7 7.0 -0.1 0.7 2.3 Geopotential height difference 700 mb at Slidell (m) -1.2 9.3 5.0 1.6 -6.7 Wind speed yesterday 700 mb at Jacksonville (ms -1 ) 7.6 8.1 6.8 6.0 9.0 Wind speed yesterday 700 mb at Slidell (ms -1 ) 4.6 6.2 5.7 5.5 8.8 Wind direction yesterday 700 mb at Jacksonville (degrees) 279 320 281 330 297 Wind direction yesterday 700 mb at Slidell (degrees) 297 342 360 353 297 Wind speed yesterday 850 mb at Jacksonville (ms -1 ) 6.3 6.4 3.6 4.2 5.9 Wind speed yesterday 850 mb at Slidell (ms -1 ) 4.6 6.2 5.7 4.4 8.0 Wind speed AM 850 mb at Jacksonville (ms -1 ) 6.7 4.9 5.8 4.4 7.3 Wind speed AM 850 mb at Slidell (ms -1 ) 5.2 5.0 5.0 4.0 6.1 Wind speed PM 850 mb at Jacksonville (ms -1 ) 6.3 6.4 3.6 4.7 5.1 Wind speed PM 850 mb at Slidell (ms -1 ) 5.2 5.6 4.8 4.3 5.1 Wind direction yesterday 850 mb at Jacksonville (degrees) 270 360 n/a 9 342 Wind direction yesterday 850 mb at Slidell (degrees) 351 6 90 21 360 Wind direction AM 850 mb at Jacksonville (degrees) 262 262 169 243 304 Wind direction AM 850 mb at Slidell (degrees) 180 243 121 149 360 Wind direction PM 850 mb at Jacksonville (degrees) 217 211 166 225 297 Wind direction PM 850 mb at Slidell (degrees) 270 236 90 29 360 Recirculation at Slidell 0.3 0.2 360 0.2 0.0 Cloud average 1.7 1.2 1.7 1.6 1.6Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis

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### 3-185 VISTAS Meteorological Characterization

06-046 December 8, 2006 Table 3-17h. Summary of Average Input Parameters for Key Bins for CART Classification Categories 3 and 4: PM 2.5 CART Analysis for SEARCH Site Oak Grove.
The ranges in PM2.5 for Categories 3 and 4 are 20-27.5 and ≥ 27.5 μ gm-3.

Class 3 Class 4
Bin 19 Bin 29 Bin 14 Bin 31 Bin 26
PM 2.5

Parameters Yesterday's FM at Gulfport (μg/m 3 ) 19.4 23.8 14.7 26.0 22.3 Yesterday's FM at Oak Grove (μg/m 3 ) 19.7 22.9 17.1 35.0 22.8 Yesterday's FM at Pensacola (μg/m 3 ) 18.6 28.6 17.1 24.6 30.73 Yesterday's FM at New Orleans/Baton Rouge (μg/m 3 ) 23.8 22.9 16.8 29.3 26.4 Surface Meteorological Parameters Max. surface temperature (°C) 28.6 33.0 29.3 28.7 25.5 Min. surface temperature (°C) 16.2 20.1 14.4 17.2 14.3 Relative humidity (%) 65.2 71.2 62.4 67.6 65.8 Surface wind speed (ms -1 ) 1.0 1.2 1.4 1.1 1.2 Surface wind direction (degrees) 75 180 360 321 76 Persistence 0.7 0.8 0.8 0.7 0.8 Station pressure (mb) 1012 1010 1011 1010 1011 Rainfall (inches) 0.0 0.0 0.0 0.0 0.0 Rain (# periods) 0.2 0.12 0.1 0.2 0.5 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 14.0 17.0 14.6 13.7 11.7 Temperature PM 850 mb (°C) 13.6 18.0 15.4 14.7 12.3 Stability at Slidell (°C) 1.1 0.0 2.7 1.6 0.9 Geopotential height difference 700 mb at Slidell (m) -0.1 4.0 3.7 5.6 6.4 Wind speed yesterday 700 mb at Jacksonville (ms -1 ) 6.3 5.2 7.9 9.0 5.1 Wind speed yesterday 700 mb at Slidell (ms -1 ) 5.9 4.9 7.1 7 6.4 Wind direction yesterday 700 mb at Jacksonville (degrees) 323 8 315 297 270 Wind direction yesterday 700 mb at Slidell (degrees) 329 27 329 328 309 Wind speed yesterday 850 mb at Jacksonville (ms -1 ) 4.8 4.4 4.2 4.7 3.9 Wind speed yesterday 850 mb at Slidell (ms -1 ) 5.4 4.4 6.3 4.8 4.5 Wind speed AM 850 mb at Jacksonville (ms -1 ) 5.1 4.7 4.0 6.5 4.5 Wind speed AM 850 mb at Slidell (ms -1 ) 4.6 3.9 4.3 4.5 5.4 Wind speed PM 850 mb at Jacksonville (ms -1 ) 4.8 4.4 5.5 5.0 6.6 Wind speed PM 850 mb at Slidell (ms -1 ) 5.7 4.3 5.0 4.5 5.7 Wind direction yesterday 850 mb at Jacksonville (degrees) 90 342 315 307 270 Wind direction yesterday 850 mb at Slidell (degrees) 48 23 14 0 333 Wind direction AM 850 mb at Jacksonville (degrees) 194 270 326 275 207 Wind direction AM 850 mb at Slidell (degrees) 243 90 45 278 198 Wind direction PM 850 mb at Jacksonville (degrees) 149 284 146 304 153 Wind direction PM 850 mb at Slidell (degrees) 52 63 56 10 27 Recirculation at Slidell 0.2 0.3 0 0.4 0.2 Cloud average 1.7 1.7 1.6 1.7 1.8Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Examination of Relationships between Me teorological and Air Quality Data Using Classification and Regressi on Tree (CART) Analysis



### For Atlanta, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 30 to 37.5 and greater than or equal to 37.5 μ gm -3 

### , respectively. There are three Category 3 and three Category 4 bins that meet the criteria for key bins. The Category 4 bins tend to have lower average relative humidity, greater stability, and higher prior-day PM 2.5 

### concentrations, than the Category 3 bins, but many of the characteristics are similar between the two groups of bins. The Category 4 bins are characterized by very low surface wind speeds. Surface wind directions are from the southwest (Bin 19), northwest (Bin 23), and northeast (Bin 26). Two of the Category 4 bins have cooler minimum temperatures than the other key bins and greater stability. This same tendency is reflected in the wind directions aloft. In contrast, southeasterly wind components are associated with the two of the Category 3 bins. CART appears to have identified three distinct high PM 2.5 

### concentration regimes.
For Birmingham, the PM 2.5 

### concentration ranges for Categories 3 and 4 are 30 to 37.5 and greater than or equal to 37.5 μ gm -3 

### , respectively. There are two Category 3 and three Category 4 bins that meet the criteria for key bins. All of the key bins are characterized by very low surface wind speeds. Two of the three Category 4 bins are distinguished from the Category 3 bins by lower average relative humidity. The third bin is distinguished from the Category 3 bins and all other key bins by lower temperatures. Bin 25 (Category 4) is very similar to Bin 10 (Category 3), in terms of the average parameter va lues, with the exception of the prior-day PM concentration for Birmingham. A much higher prior-day value for Bin 25 likely contributes to the higher PM 2.5 

### values and higher category designation. Bins 20 and 24 are differentiated by wind directions. Surface winds are northeasterly for Bin 20 and southerly for Bin 24, compared to northwesterly for Bin 25 and the key Category 3 bins. Upper-level winds are southerly to southwesterly for Bin 20 and (more typically) westerly to southwesterly for Bin 24.
Figure 3-9 shows the average composition for all key PM 2.5 

### bins for each of the SEARCH sites.

Figure 3-9a. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Atlanta.

Atlanta SEARCH Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

1 (751) 7 (146) 4 (116) 8 (43) 5 (39) 3 (33) 28 (15) 31 (12) 21 (16) 19 (18) 23 (7) 26 (5)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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Figure 3-9b. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Yorkville.

Yorkville SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (793) 2 (204) 20 (47) 5 (62) 11 (40) 8 (26) 18 (18) 28 (13) 6 (14) 22 (23) 29 (7) 15 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-9c. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Birmingham.

Birmingham SEARCH Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

5 (568) 9 (213) 27 (137) 4 (53) 31 (47) 28 (24) 10 (22) 14 (29) 25 (24) 20 (9) 24 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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Figure 3-9d. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Centreville.

Centreville SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (672) 3 (115) 2 (112) 10 (80) 7 (45) 24 (33) 16 (34) 20 (19) 9 (9) 28 (16) 18 (8) 21 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-9e. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Pensacola.

Pensacola SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (581) 3 (8) 2 (1) 10 (1) 7 (1) 24 (2) 16 (4) 20 (13) 9 (1) 28 (2) 18 (6)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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Figure 3-9f. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Outlying Landing Field.

Outlying Landing Field SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00

1 (650) 2 (195) 23 (98) 16 (100) 24 (27) 9 (35) 25 (32) 13 (12) 28 (33)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure 3-9g. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Gulfport.

Gulfport SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00

1 (689) 2 (193) 27 (83) 25 (49) 9 (44) 8 (30) 29 (17) 12 (18) 10 (10) 30 (40) 16 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

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Figure 3-9h. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4)

Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: SEARCH Site Oak Grove.

Oak Grove SEARCH Key PM Bins: Component Averages

0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00

1 (668) 7 (106) 8 (88) 22 (78) 3 (71) 9 (38) 19 (26) 29 (25) 14 (12) 31 (21) 26 (11)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4



### The compositional charts for the PM 2.5 

### for the SEARCH sites also show a much larger proportional contribution from organics than the IMPROVE charts, especially for the higher PM 2.5 

### bins. The relative ranking of the species contributions is similar to that for the STN sites. A comparison of the compositional averages for Birmingham using the STN (Figure 3-8a) and SEARCH (Figure 3-9c) data, shows that the organic matter and overall PM 2.5 

### values are higher in the STN data, but that the tendency for organic matter to be the dominant species appears in both sets of results.
The compositional analysis results for Birmingham (Figure 3-9c) also show a higher contribution of elemental carbon than for most other sites, and this may be related to emissions from the steel industry facilities that are located in Birmingham.
For all three of the key Category 4 PM 2.5 

### bins for Birmingham (Bins 25, 20, and 24), organic matter is the dominant species. However, the relative proportion of the species concentrations is different for each bin. This may be due to the differences in the average wind directions. All of the key bins are characterized by very low surface wind speeds, but, on average, the days within the bins have different wind directions. Surface winds are northwesterly for Bin 24, northeasterly for Bin 20, and southerly for Bin 24. We noted earlier that Bin 25 (Category 4) is very similar to Bin 10 (Category 3), in terms of the average parameter values, with the exception of the prior-day PM concentration for Birmingham. The two bins have similar species distributions, and the higher values for Bin 24 are due to slight increases in sulfate and organic matter and a greater increase in elemental carbon.

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## 4. Meteorological Representa tiveness and Episode
Selection Exercises
The CART results and a meteorological characterization and episode selection tool, based on these results, were used to provide information related to the representativeness of the model year 2002 and the periods selected by VISTAS for model performance evaluation and preliminary sensitivity testing, relative to the five-year regional haze baseline period. The CART results and tool were also used in selecting subset periods of 2002 for PM 2.5 

### modeling and sensitivity analysis, and in the calculation of weighting factors related to regional haze and PM 2.5 

### for the modeled days. These exercise s are described in this section. A comparison of the results for Birmingham using the STN and SEARCH datasets is provided in the appendix. 

## 4.1. Meteorological Characterization and Episode Selection Tool
In this study, the CART results served as the basis for developing a tool capable of addressing questions regarding the representativeness of selected episodic and annual simulation periods as well as the selection of discrete multi-day periods for refined modeling or control-strategy evaluation. The CART results (groupings of days with similar characteristics) were coupled with characterization and episode selection algorithms in order to provide this information. The VISTAS meteorological characterization tool is available in electronic format.
For any input set of days, the characterization algorithm assesses and summarizes the range, type, and frequency of sampling of the CART bi ns; the degree to which key characteristics (CART bins) are represented; mean values for al l parameters, including chemical speciation; representation of the days comprising the regional metrics, and ability to represent the regional haze metrics or PM 2.5 

### annual average or design values (estimated using error statistics) for one or more sites selected by the user. A summary of the meteorological parameters for the selected days is also optionally provided, together with an assessment of whether or not the conditions are typical of the full analysis period.
The episode selection algorithm, based on the EPI SODES p rogram that we originally developed for SAMI, identifies episodes characterized by typical (frequently occurring) meteorological conditions and representative of the multi-year visibility and PM 2.5 

### metrics. The selection of days is guided by user-input episode selection criteria pertaining to the number of days, contiguousness and length of episode periods, and error tolerance in representing the regional haze metrics. The days identified by the episode selection algorithm can then be summarized using the characterization algorithm.
Figure 4-1 diagrams the VISTAS meteorological characterization and episode selection tool.

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Figure 4-1. Schematic Diagram of the VISTAS Meteorological Characterization and Episode Selection Tool.

PM Data (IMPROVE, STN, and SEARCH) Visibility Meteorological Data

CART

CART classification algorithm/variable importance Conceptual model for visibility (and, optionally, PM 2.5 ) Classification category and bin characteristics

06 

### Together the CART results and the meteorological characterization and episode selection tool were

use d to provide information related to the representativeness of the model year 2002 and the periods selected by VISTAS for model performance evaluation and preliminary sensitivity testing. used to provide information related to the representativeness of the model year 2002 and the



## 4.1.1. Meteorological Characterization Component
In the characterization mode, the user inputs a date or series of dates and the tool provides information about those dates. The user must select the type of analysis (visibility or PM 2.5 

### ) by selecting the appropriate button. He/she may also select the meteorology option by checking that box. He/she must also select the desired site(s) and either enter the dates manually or read them in from an external file by clicking on the “Read Dates” button. The tool will accept any dates included in the analysis period, which currently includes the years 2000-2004. The dates must be in yymmdd format. The initial input screen for an example application for PM 2.5 

### for the STN sites and the Atlanta, Birmingham, Gulfport, and Pensacola SEARCH sites for 3 June – 10 July 2002 is displayed in Figure 4-2. The user must select the type of analysis (visibility or PM 2.5 

### ) by selecting the appropriate button. He/she may also select the meteorology option by checking that box. He/she must also select the desired site(s) and either enter the dates manually or read them in from an external file by clicking on the “Read Dates” button. The tool will accept any dates included in the analysis period, which currently includes the years 2000-2004. The dates must be in yymmdd format. The initial input screen for an example application for PM 2.5 

### for the STN sites and the Atlanta, Birmingham, Gulfport, and Pensacola SEARCH sites for 3 June – 10 July 2002 is displayed in Figure 4-2. EPISODES CART Results

CHARACTERIZATION ALGORITHM

Alternate/subset modeling periods Summary of characteristics, representativeness, and error statistics Conceptual Desc ription

Meteorological Characterization Episode Selection User-specified episode selection parameters User-specified dates/periods

of interest

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Figure 4-2. Initial Input Screen for the Characterization Portion of the VISTAS Meteorological Characterization T ool: Example for PM2.5 for all STN Sites Plus the Atlanta, Birmingham, Gulfport, and Pensacola SEARCH Sites, for 6/3/02-7/10/02.



### Once the dates are entered, the user must select from among the Visibility Metrics

, PM2.5 Metrics , or Meteorological Metrics buttons to obtain the results. For both visibility and PM, key metrics summarize how well the days represent:

• Frequently occurring meteorological conditions, as identified by CART

– Number and type of key 1 

### bins represented.

– Percent of key bins represented wit hin each classification category.

– Distribution of days within the key bins, relative to the full analysis period.

– Distribution of days within all bins, relative to the full analysis period.

For visibility, the output also includes the following regional haze metrics, where the 20 percent worst and best days are defined, respectively, as the 20 percent haziest and 20 percent clearest days in the 2000-2004 baseline period:

• Mean extinction coefficie nt, calculated using a CART-based frequency weighting of the days. The average is calculated in this manner so that it can be compared with annual mean

1 Key bins for each category are those containing the greatest num ber of correctly classified days. Approximately three key bin s were selected for each classification category for each site.

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### extinction coefficient values and to determine whether the extinction coefficients for the selected subset of days are representative of a selected or typical annual period.

• Range of extinction coefficient.

• Quarterly di stribution relative to the 20 percent best and worst days.

• Dates of the selected da ys that are also among the 20 percent best and worst days.

• Chemical composition a nd ranking of contributors to extinction coefficient and PM 2.5.


### For PM, the output also includes the following PM 2.5 

### metrics:

• PM 2.5 

### design value

• Range of PM 2.5 

### concentrations.

• Annual average PM 2.5 

### concentration, calculated using a CART-based frequency weighting of the days. The average is calculated in this manner so that it can be compared with annual average concentrations, including those that comprise the design value. The objective is to determine whether the concentrations for the selected subset of days are representative of a selected or typical annual period.

• Quarterly di stribution relative to the 20 percent best and worst days.

• Chemical composition a nd ranking of contributors to PM 2.5.


### An example result for PM 2.5 

### is given in Figure 4-3.

Figure 4-3. Example Characterizat ion Result Screen for PM2.5.

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### For meteorology, the output includes the bin and CART category into which each date falls as well as the maximum temperature, relative humidity, wind speed and direction, and precipitation on that date. It also includes the number and percent of the selected days that have atypical meteorological conditions.
There are also several options for graphical display of the results (these are obtained by clicking on the miniature bar cha rts next to the metric descriptors).
The characterization tool was used during the course of the project to examine the representativeness of the two episode periods selected for air qualit y model performance evaluation, and to refine the selection of the two episode periods that were used for model sensitivity analysis.



## 4.1.2. Episode Selection Component
In the episode selection mode, the user specifies criteria for episode selection (such as total number of days, sites to optimize over, relative importance of various control factors, etc.) and the analytic tool provides a list of episode dates. These dates can subsequently be input to the characterization scheme to obtain information about the episodes.
The user must select the type of analysis (visibility or PM 2.5 

### ), by selecting the appropriate button, and select the number (up to 8) and name(s) of the sites from two drop-down menus. He/she may enter the desired number of days (the default is 40), and check a box if he/she wishes to use only properly classified days. The user may also enter values for other control factors, including a distance factor, chain factor, and season factor. The relative values of these factors (and not the absolute values) guide the episode selection and spec ify the relative importance of 1) representing annual average values of visibility (or PM 2.5 

### ), 2) including consecutive days, and 3) representing all seasons in the episode selection results. The distance factor determines the relative emphasis on selecting days (combined) that represent the wei ghted annual average value of extinction coefficient or PM 2.5 

### (whichever is selected) and thus the key bi ns. The chain factor determines the degree to which consecutive days are sought. The season factor weights the degree to which the different seasons are represented by the selected dates. Finally, the user may check a box if he/she wishes to consider only days from particular classification categories. If so, he/she then has the opportunity to select those categories from a menu. The initial input screen for an example application for PM 2.5 

### for the Atlanta SEARCH site is displayed in Figure 4-4.

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Figure 4-4. Initial Input Screen for the Episode Selection Portion of the VISTAS Meteorological Characterization Tool: Example for PM2.5 for Atlanta.



### Once the inputs are entered, the Run button is selected and the results screen appears. This summarizes the total number of episodes (defined by contiguous days), combined error summary for all selected sites, and site-specific errors. The errors summarize how well the selected episodes represent annual average values. The combined-site errors include an average error (the average difference in extinction coefficient or concentration), optimized cost (a relative measure of how well the distance, chain and season criteria are met), and average biased error (biased or signed error, averaged over all sites). The site-specific errors include the distance error (which quantifies the representation of the annual average value of the parameter, scaled to compensate for bins that are not represented) and the biased error (same as the distance error but not scaled to account for missing bins). By clicking on the Save Output button, the user can save and open/view a file containing the episode dates. An example results screen is shown in Figure 4-5.

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Figure 4-5. Example Episode Selection Result Screen for PM2.5.



### There is also an option for graphical display of the results (obtained by clicking on the miniature bar chart).
The episode selection component of the tool was used to guide the selection of the two episode periods that were used by VISTAS for model sensitivity analysis. 

## 4.2. Analysis of the Represen tativeness of the 2002 Simulation Period
The CART results and meteorological characterization tool were used to explore several questions related to modeling episode period representativeness. As noted earlier, the key question is: How representative is the year 2002, as selected for VISTAS atmospheric modeling, considering meteorology, fine particulate, and visibility, relative to the full baseline period. The characteristics of the 2000-2004 baseline period and each individual year comprising that period are examined and compared in this section.


## 4.2.1. IMPROVE Sites
Table 4-1 summarizes and compares 2000-2004, and each individual year within this period for the IMPROVE sites. The summary metrics included in this table are the weighted average extinction coefficient, weighted average PM 2.5 

### concentration, range in PM 2.5 

### concentration, percentage of key visibility bins represented (considering all classes), the relative distribution of days among the key visibility bins for all categories (distribution error), percentage of key PM 2.5 

### bins represented (considering all classes), and the relative distribution of days among the key PM 2.5 

### bins for all categories (distribution error). These terms are explained in more detail, in the discussion following Table 4-1.

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Table 4-1. Summary of Visibility, PM 2.5, and Meteorological Characteristics for the 2000-2004 Analysis Period: IMPROVE Sites. (a) Breton

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility Bi ns Represented (%) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 78.5 7.6 1.2 – 21.5 100 2000 92.5 9.4 4.3 – 17.2 100 1.9 100 2.9 2001 78.3 7.7 2.2 – 20.3 100 1.3 100 1.4 2002 71.2 6.7 1.8 – 16.4 100 1.6 100 0.7 2003 79.5 7.6 1.7 – 19.7 100 0.9 100 0.9 2004 80.5 7.9 1.2 – 21.5 100 1.3 100 1.3
(b) Brigantine

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 95.6 9.7 1.4 – 39.2 2000 100.2 10.1 1.5 – 27.3 100 0.9 100 0.8 2001 86.1 9.3 2.6 – 30.1 100 1.3 100 2.1 2002 93.6 9.6 1.4 – 36.5 100 0.9 100 1.7 2003 96.7 9.8 1.8 – 39.2 100 1.7 100 1.1 2004 92.5 9.6 3.0 – 28.6 100 1.3 100 1.6
(c) Cadiz

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 107.4 11.0 0.6 – 31.3 2000 NA NA NA NA NA NA NA 2001 100.4 10.9 0.6 – 27.1 100 1.7 100 1.6 2002 107.4 11.1 4.1 – 30.2 100 1.1 100 1.0 2003 111.4 11.1 3.0 – 31.1 100 1.3 100 0.5 2004 105.3 11.1 2.2 – 26.5 100 1.1 100 1.5

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(d) Caney Creek

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 83.0 9.0 0.3 – 28.3 2000 85.8 9.0 0.3 – 22.4 100 1.6 100 1.7 2001 79.1 9.3 0.9 – 21.6 100 1.0 100 1.4 2002 92.1 8.9 0.5 – 28.3 100 0.9 100 1.0 2003 87.5 8.8 1.5 – 25.1 100 1.0 100 1.2 2004 80.9 8.6 0.4 – 19.0 100 1.2 100 1.3
(e) Cape Romain

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 82.0 8.6 1.1 – 30.1 2000 90.5 9.4 2.7 – 24.9 100 1.2 100 2.2 2001 77.2 8.6 2.0 – 21.9 100 0.5 100 1.0 2002 79.8 8.0 1.1 – 22.6 100 1.3 100 1.1 2003 74.0 8.0 1.5 – 18.5 100 1.0 100 1.1 2004 88.7 8.7 1.3 – 30.1 100 0.8 100 1.1
(f) Chassahowitzka

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 89.5 8.7 2.1 – 24.7 2000 96.2 8.8 3.3 – 24.7 100 1.7 100 1.9 2001 88.9 8.8 2.1 – 20.7 100 0.7 100 0.6 2002 86.5 8.2 2.5 – 17.7 100 1.1 100 1.6 2003 69.6 7.8 3.4 – 13.4 100 1.7 100 2.2 2004 NA NA NA NA NA NA NA

ICF International 

### 4-9 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Meteorological Representativeness and Episode Selection Exercises

(g) Cohutta

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 95.6 10.7 1.2 – 44.4 2000 128.2 12.8 3.9 – 32.7 100 1.7 100 1.4 2001 87.3 9.8 1.8 – 29.6 100 1.0 100 1.0 2002 95.4 10.6 2.2 – 44.4 100 1.2 100 1.3 2003 92.9 10.4 1.2 – 34.3 100 1.2 100 1.5 2004 98.4 10.1 1.9 – 32.4 100 1.5 100 1.3
(h) Dolly Sods

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 86.0 9.4 0.4 – 37.2 2000 89.3 10.4 1.3 – 26.1 100 1.1 100 1.7 2001 82.0 8.9 2.0 – 35.7 100 0.7 100 1.5 2002 79.1 8.7 1.3 – 37.2 100 1.0 100 0.9 2003 91.5 9.8 0.4 – 29.8 100 1.0 100 1.3 2004 80.8 9.9 0.9 – 31.2 100 1.5 100 1.3
(i) Everglades

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 63.4 6.5 1.1 – 34.4 2000 70.5 6.2 1.1 – 24.9 100 2.3 100 2.5 2001 63.1 6.0 1.8 – 17.5 100 1.1 100 1.3 2002 61.8 6.3 1.4 – 23.4 100 1.0 100 1.3 2003 67.6 7.2 1.7 – 24.1 100 1.3 100 1.3 2004 62.0 6.6 2.1 – 34.4 100 1.5 100 1.1

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(j) Great Smoky Mountains

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 85.7 10.1 0.5 – 35.6 2000 92.3 10.5 2.3 – 35.6 100 1.8 100 1.7 2001 82.2 9.8 1.8 – 29.9 100 1.0 100 1.3 2002 78.6 9.8 1.7 – 27.9 100 1.1 100 0.7 2003 86.7 9.9 0.5 – 32.1 100 1.1 100 1.5 2004 86.0 10.3 1.5 – 23.9 100 1.1 100 1.2
(k) James River Face

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 102.1 10.9 0.5 – 31.5 2000 128.5 12.9 4.5 – 26.9 100 1.3 100 1.4 2001 97.1 10.1 2.8 – 28.9 100 1.4 100 0.9 2002 101.0 11.7 3.5 – 31.5 100 1.3 100 1.1 2003 99.6 10.3 0.5 – 29.2 100 1.3 100 1.4 2004 94 10.0 2.4 – 25.9 100 1.0 100 1.0
(l) Linville Gorge

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 80 8.9 0.3 – 29.2 2000 94.2 10.4 1.3 – 29.2 100 1.5 100 1.7 2001 78.1 8.3 15 – 23.8 100 1.1 100 0.9 2002 72.4 8.8 1.6 – 27.1 92.3 1.7 100 1.0 2003 78.8 8.3 0.3 – 27.6 100 1.5 100 1.1 2004 77.0 8.6 1.5 – 21.6 100 1.0 100 0.9

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(m) Mammoth Cave

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 110.0 11.7 2.0 – 44.6 2000 116.5 12.7 4.0 – 44.6 100 1.6 100 2.1 2001 105.7 11.3 2.0 – 28.4 100 1.7 100 1.3 2002 104.1 11.5 3.8 – 34.0 100 0.8 100 1.4 2003 106.2 11.5 3.9 – 32.4 100 1.1 100 1.1 2004 109.5 11.5 2.5 – 27.6 100 1.5 100 2.0
(n) Mingo

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 94.7 11.5 2.4 – 50.0 2000 101.5 12.9 2.6 – 34.5 100 1.8 100 1.2 2001 90.4 11.3 2.4 – 50.0 100 1.1 100 1.2 2002 80.9 9.1 3.1 – 15.4 100 1.2 100 2.4 2003 NA NA NA NA NA NA NA 2004 NA NA NA NA NA NA NA
(o) Okefenokee

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 86.7 9.1 2.2 – 42.9 2000 94.3 9.5 3.5 – 24.8 100 1.5 100 1.9 2001 85.3 9.5 3.0 – 24.9 100 1.3 100 1.1 2002 88.9 9.5 2.9 – 30.1 100 1.0 100 0.7 2003 81.5 8.5 2.2 – 20.4 100 1.0 80 1.2 2004 85.4 9.0 2.8 – 42.9 100 1.2 100 0.9

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(p) Shenandoah

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 95.2 9.3 0.1 – 33.9 2000 96.9 9.3 0.7 – 22.7 100 1.6 100 0.9 2001 99.4 9.5 1.7 – 33.9 100 1.1 100 1.0 2002 99.0 9.6 0.8 – 29.8 100 2.2 100 1.8 2003 95.0 9.3 0.1 – 29.3 100 1.2 100 1.3 2004 89.9 8.7 0.5 – 26.1 100 1.6 100 0.4
(q) Shining Rock

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 75.1 7.8 0.2 – 57.6 2000 85.4 8.3 1.6 – 57.6 100 1.3 100 0.9 2001 74.5 7.8 1.1 – 24.1 100 1.1 100 0.9 2002 65.0 8.1 0.4 – 23.2 100 1.3 100 1.2 2003 84.2 8.4 0.2 – 34.8 100 1.6 100 1.4 2004 65.3 7.0 0.9 – 17.8 100 1.1 100 0.9
(r) Sipsey

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 100.8 11.1 1.6 – 36.3 2000 104.9 11.6 3.9 – 36.3 100 2.0 100 3.1 2001 100.8 10.7 1.6 – 23.0 100 1.1 100 1.5 2002 95.9 10.8 4.4 – 29.0 100 1.2 100 1.2 2003 104.1 11.7 4.0 – 28.6 100 1.0 100 1.0 2004 95.6 10.8 31 – 26.0 100 1.2 100 1.7

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(s) St. Marks

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 77.9 8.5 1.5 – 31.9 2000 88.5 9.0 3.4 – 20.1 100 1.5 100 1.9 2001 78.9 8.2 2.0 – 18.4 100 0.9 100 1.0 2002 79.2 8.1 2.3 – 21.4 100 1.0 100 1.7 2003 81.1 8.3 1.5 – 23.8 91.7 1.0 100 1.9 2004 73.9 9.4 2.8 – 31.9 100 1.4 100 1.3
(t) Swanquarter

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 81.8 7.9 0.6 – 27.0 2000 89.7 8.3 2.2 – 17.6 100 0.6 100 2.4 2001 79.0 7.7 1.8 – 24.9 100 1.3 100 1.9 2002 79.3 8.1 1.8 – 22.2 100 1.3 100 1.9 2003 78.8 7.1 0.6 – 27.0 100 1.1 100 0.9 2004 NA NA NA NA NA NA NA
(u) Upper Buffalo

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 73.4 8.6 0.1 – 30.0 2000 81.0 9.3 1.1 – 30.0 100 1.1 100 1.4 2001 64.8 7.9 0.7 – 20.7 100 0.8 100 1.4 2002 79.2 9.2 1.7 – 27.1 100 1.0 100 1.6 2003 77.8 9.1 0.1 – 25.1 100 1.7 100 1.5 2004 67.0 8.6 0.7 – 23.5 100 1.3 100 1.3



### The weighted average is the average of the daily values that are weighted according to the frequency of occurrence of similar conditions for the full period. The weights are based on the CART results, and frequency of occurrence of conditions is based on the number of days in

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### each CART bin. Days that have conditions that occur more frequently are given greater weights, while those that occur less frequently are given lesser weights. In this manner, the frequency of occurrence of meteorological conditions is nor malized for each year and the average extinction coefficient and PM 2.5 

### values are more likely to reflect other factors such as emissions. Unusually high or low concentrations/extinction for a certain type of conditions (severity) will also affect the average. For many of the sites, the highest extinction and PM 2.5 

### values occur in 2000. Otherwise the values are fairly similar for all years. The range in PM 2.5 

### , which is not normalized for meteorology, is also similar for each of the five years.
For all sites, the key bins for both visibility and PM 2.5 

### are represented for all of the years, although there are a few exceptions. This is expected since we are considering full year periods, each of which represents one fifth of the multi-year period that is used to determine the key bins. As we will see later in this report, this metric is more informative when we consider shorter, episodic periods.
The distribution error ranges quantifies how well the frequency distribution of days among the bins matche s that for the full baseline period. It has the units of percent since it is the average difference of two percentage values. For all sites, this value ranges from approximately 0.5 to 3 percent. A smaller error indicates a better match. Considering this metric, 2002 does not stand out as being significantly more or less repres entative than the other years that comprise the baseline period. No one year stands out as being most typical of the period for a majority of the sites. The distribution error over all key visibility bins is lowest for 2002 for Brigantine, Cadiz, Caney Creek, Everglades, Mammoth Cave, and Okefenokee. The results vary by site.
For example, for Cape Romain (Table 4-1e), the weighted extinction and PM 2.5 

### values for 2002 are lower than on average for the full baseline period. The range in PM 2.5 

### is typical of the other baseline years. The distribution error for visibility is slight ly larger than for the other years in the period, and that for PM 2.5 

### is about the same as the other years (except for 2000, which is quite a bit higher).
For the GSM site (Table 4-1j), the weighted average extinction coefficient for 2002 is lower than on average for the full ba seline period, but the average PM 2.5 

### value is typical of the period. The range in PM 2.5 

### is also typical of the other baseline year s. The distribution error for visibility is about the same as the other years (except for 2000, which is quite a bit higher), that for PM 2.5 

### is the lowest among the five years.
For Mammoth Cave (Table 4-1m), the weighted extinction and PM 2.5 

### values for 2002 are representative of the full baseline period, but slightly below the average values for the full period. The year 2000 has some high values, which tend to increase the five-period average. The range in PM 2.5 

### is typical of the other baseline years, with the exception of 2000. The distribution error for visibility is the lowest among all of the years, while that for PM is in the middle.
Considering the entire VISTAS region, it is not expected that any single year will be typical or representative for all areas of the Class I areas of interest. The year 2000 seems to be the least representative year, and 2002 is as good as or better than most of the others for most sites. Knowing how well the 2002 simulation period represents each area may aid the analysis and interpretation of the VISTAS air quality modeling results.



## 4.2.2. STN Sites
Table 4-2 summarizes and compares 2000-2004, and each individual year within this period for the STN sites. The summary metrics included in this table are the weighted average PM 2.5

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### concentration, range in PM 2.5 

### concentration, percentage of key PM 2.5 

### bins represented (considering all classes), and the relative distribution of days among the key PM 2.5 

### bins for all categories (distribution error).

Table 4-2. Summary of PM 2.5 and Meteorological Characteristics for the 2000-2004 Analysis Period: STN Sites.

(a) Birmingham

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 18.8 0.4 - 71.3 2000 20.1 0.4 - 71.3 100 2.7 2001 18.4 1.0 - 51.5 100 0.8 2002 17.8 4.2 - 47.8 100 1.1 2003 18.0 2.9 - 46.4 90 1.4 2004 18.4 3.6 – 53.3 80 1.6
(b) Charlotte

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 2.3 – 45.2 2000 15.4 2.9 – 43.5 100 1.8 2001 14.5 3.8 – 40.3 100 0.9 2002 14.4 3.2 – 45.2 100 1.6 2003 14.2 2.3 – 40.4 90 1.4 2004 14.6 2.6 – 39.8 100 1.3
(c) Chattanooga

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 15.6 2.5 – 48.6 2000 16.0 4.8 – 48.6 100 2.3 2001 15.8 2.5 – 47.5 100 1.6 2002 14.5 4.2 – 31.3 100 1.1 2003 15.4 3.0 – 41.4 90 1.6 2004 14.8 3.1 – 31.3 100 1.1

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### 4-16 VISTAS Meteorological Characterization

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(d) Greenville-Spartanburg

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.8 0.5 – 51.5 2000 15.5 3.5 – 51.5 100 1.7 2001 14.8 2.4 – 40.7 92.3 0.8 2002 14.9 1.5 – 49.8 100 1.2 2003 14.6 0.5 – 40.1 100 0.9 2004 14.5 3.1 – 38.0 100 0.7
(e) Hickory

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 15.8 2.6 – 40.7 2000 16.7 4.7 – 38.0 100 1.1 2001 15.6 3.8 – 40.0 100 0.9 2002 15.5 4.5 – 40.7 100 0.9 2003 16.1 2.6 – 39.8 100 1.2 2004 15.7 3.2 – 37.4 100 1.0
(f) Huntington-Ashland

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 0.6 – 54.5 2000 15.7 0.6 – 37.2 100 1.8 2001 14.1 3.1 – 54.5 100 1.3 2002 14.9 3.0 – 46.8 100 1.0 2003 15.5 5.2 – 37.7 100 1.1 2004 13.2 3.2 – 30.7 100 0.8

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(g) Jackson

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 13.7 1.8 – 45.3 2000 14.0 3.2 – 41.4 100 1.1 2001 13.3 1.8 – 40.3 100 1.5 2002 13.0 1.8 – 45.3 100 2.0 2003 13.5 4.5 – 31.5 100 0.7 2004 13.6 2.3 – 33.6 100 2.0
(h) Kingsport-Bristol

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.8 1.9 – 49.2 2000 15.8 4.3 – 43.0 100 1.8 2001 14.6 3.2 – 45.7 100 1.4 2002 14.0 2.6 – 37.5 100 0.8 2003 14.3 1.9 – 49.2 100 1.5 2004 14.2 3.8 – 37.7 100 1.5
(i) Louisville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.1 3.3 – 100.6 2000 17.4 3.5 – 54.7 100 1.5 2001 17.3 100 3.5 – 53.2 0.9 2002 17.7 4.1 – 100.6 100 1.0 2003 3.5 – 55.7 91.7 0.9 16.4 2004 15.9 3.3 – 45.8 75 1.2

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(j) Macon

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 16.1 1.6 – 56.2 2000 16.8 3.8 – 56.2 100 2.1 2001 15.9 1.6 – 39.7 100 1.4 2002 15.2 4.3 – 41.0 100 1.2 2003 15.2 3.5 – 36.3 100 1.6 2004 16.2 4.0 – 43.8 100 1.7
(k) Memphis

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.2 1.1 – 50.0 2000 15.2 1.1 – 50.0 100 1.6 2001 13.8 2.7 – 41.3 100 0.9 2002 13.8 3.6 – 49.4 91.7 0.8 2003 14.0 3.2 – 38.0 100 0.7 2004 13.8 3.1 – 38.2 91.7 1.6
(l) Montgomery

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 0.4 – 52.1 2000 16.1 0.4 – 52.1 100 2.4 2001 13.7 0.6 – 38.8 100 1.4 2002 14.9 3.5 – 39.4 100 0.7 2003 14.2 5.1 – 42.8 90 1.3 2004 14.4 5.3 – 45.0 100 1.8

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(m) Nashville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.9 0.2 – 42.3 2000 15.6 0.5 – 42.3 100 2.0 2001 14.8 0.2 – 38.2 90.9 0.8 2002 14.6 2.6 – 39.8 100 1.1 2003 14.9 4.2 – 42.3 100 0.7 2004 13.8 2.2 – 36.6 100 1.4
(n) Raleigh

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.1 2.3 – 52.8 2000 15.0 3.0 – 52.8 100 1.4 2001 13.9 3.7 – 48.7 91.7 1.0 2002 13.3 2.3 – 43.8 91.7 1.6 2003 14.2 2.8 – 45.3 100 0.9 2004 13.5 2.8 – 41.7 100 1.1
(o) Richmond

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.2 0.0 – 50.5 2000 14.9 2.2 – 38.9 100 1.0 2001 14.3 2.0 – 49.1 100 0.5 2002 13.0 1.2 – 50.5 100 1.0 2003 14.0 2.8 – 43.5 100 1.1 2004 13.5 0.0 – 38.2 92.3 0.7

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(p) Savannah

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.0 3.2 – 55.3 2000 14.7 4.7 – 44.5 100 2.3 2001 14.9 3.2 – 55.3 100 1.4 2002 12.8 3.9 – 30.1 100 1.5 2003 13.5 4.1 – 49.6 88.9 0.6 2004 13.4 4.7 – 40.2 100 2.1



### The weighted average PM 2.5 

### values tend to be highest for 2000. Otherwise the values are fairly similar for all years, with some variations. The range in PM 2.5 

### , which is not normalized for meteorology, is also similar for each of the fi ve years. Figure 4-6 shows the year by year tendencies in weighted average PM 2.5 

### and daily maximum 24-hour average PM 2.5 

### , for each of the STN sites. For most sites, there is no apparent trend, especially for the meteorologically adjusted (weighted average) values. This indicates that PM 2.5 

### concentrations in the urban areas have neither increased nor decreased during the five-year period.

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Figure 4-6. Year-by-Year Tendencies in Weighted Average PM 2.5 and Daily Maximum 24-hour Average PM 2.5 (a) Birmingham



### Weighted Average PM2.5: Birmingham

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Birmingham

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(b) Charlotte



### Weighted Average PM2.5: Charlotte

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Charlotte

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(c) Chattanooga



### Weighted Average PM2.5: Chattanooga

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Chattanooga

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(d) Greenville-Spartanburg



### Weighted Average PM2.5: Greenville-Spartanburg

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Greenville-Spartanburg

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(e) Hickory



### Weighted Average PM2.5: Hickory

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Hickory

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(f) Huntington-Ashland



### Weighted Average PM2.5: Huntington-Ashland

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Huntington-Ashland

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(g) Jackson



### Weighted Average PM2.5: Jackson

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Jackson

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(h) Kingsport



### Weighted Average PM2.5: Kingsport-Bristol

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Kingsport-Bristol

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(i) Louisville



### Weighted Average PM2.5: Louisville

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Louisville

0 20 40 60 80 100 120

2000 2001 2002 2003 2004ugm-3

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(j) Macon



### Weighted Average PM2.5: Macon

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Macon

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(k) Memphis



### Weighted Average PM2.5: Memphis

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Memphis

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(l) Montgomery



### Weighted Average PM2.5: Montgomery

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Montgomery

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(m) Nashville



### Weighted Average PM2.5: Nashville

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Nashville

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(n) Raleigh



### Weighted Average PM2.5: Raleigh

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Raleigh

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(o) Richmond



### Weighted Average PM2.5: Richmond

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Richmond

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(p) Savannah



### Weighted Average PM2.5: Savannah

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Savannah

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3



### With few exceptions, the key bins for PM 2.5 

### are represented for all of the years. Again, this is expected since we are considering full year periods, each of which represents one fifth of the multi-year period that is used to determine the key bins.
The distribution error ranges from approximately 0.5 to 2.5 and quantifies how well the frequency distribution of days among the bins matches that for the full baseline period. No one year stands out as being most typical of the period for a majority of the sites. The distribution error over all key bins is lowest for 2002 for Chattanooga, Hickory, Kingsport-Bristol, Macon, and Montgomery, and close to the lowest for several other sites. Overall, 2000 is the year with the least representative distribution. As for the IMPROVE sites, the results vary by site.
For example, for Charlotte (Table 4-2b), the weighted PM 2.5 

### value for 2002 is close to the average for the full baseline period. The maximum concentration occurred during this year, but the range in PM 2.5 

### is typical of the other baseline years. The distribution error is slightly larger than for the other years in the period, except for 2000. The year 2001 appears to be the most typical year.

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### For Chattanooga (Table 4-2c), the weighted average PM 2.5 

### value for 2002 is lower than the average for the full baseline period and the lower values are also reflected in the range. Nevertheless, the frequency of conditions was normal and the distribution error is the lowest overall (along with that for 2004).
For Louisville (Table 4-2i), the weighted average PM 2.5 

### value for 2002 is slightly higher than the average for the full baseline period and the range indicates that there was at least one very high daily value (greater than 100 μ gm -3 

### ) recorded during 2002. The distribution error is among the lowest, indicating a typical frequency of meteorological scenarios.
For Macon (Table 4-2j), the weighted average PM 2.5 

### value for 2002 is lower than the average for the full baseline period and the range is similar to that for the other years with the exception of 2002. The distribution error is the lowest, over all the years considered.
For the urban areas, the year 2000 seems to be the least representative year, and 2002 is as good

as or better than most of the others for most sites. Consequently, 2002 is a representative year for most sites, but the specific implications of usin g 2002 as the model baseline year vary by site.



## 4.2.3. SEARCH Sites
Table 4-3 summarizes and compares 2000–2004, and each individual year within this period for the SEARCH sites. The summary metrics included in this table are the weighted average PM 2.5 

### concentration, range in PM 2.5 

### concentration, percentage of key PM 2.5 

### bins represented (considering all classes), and the relative distribution of days among the key PM 2.5 

### bins for all categories (distribution error).

Table 4-3. Summary of PM 2.5 and Meteorological Characteristics for the 2000-2004 Analysis Period: SEARCH Sites. (a) Atlanta (Jefferson St.)

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 16.6 1.1 – 66.1 2000 16.9 3.7 – 62.6 100 1.8 2001 16.4 2.2 – 66.1 100 0.9 2002 16.3 3.7 – 40.2 91.7 0.8 2003 16.2 1.5 – 47.0 100 1.0 2004 16.8 1.1 – 49.5 100 1.7

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(b) Yorkville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 13.6 0.7 – 65.2 2000 14.5 2.3 – 65.2 100 1.5 2001 13.2 2.5 – 54.4 100 0.7 2002 13.2 2.6 – 34.8 100 0.6 2003 12.0 2.2 – 43.0 91.7 1.0 2004 13.4 0.7 – 39.5 91.7 0.4
(c) Birmingham

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.9 2.8 – 75.2 2000 18.3 3.8 – 66.4 100 2.3 2001 17.2 3.3 – 48.9 100 1.1 2002 17.5 3.9 – 45.3 100 0.9 2003 16.8 2.8 – 45.0 90.9 1.4 2004 18.0 3.2 – 75.2 100 1.4
(d) Centreville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 12.9 1.2 – 54.4 2000 13.3 3.0 – 54.4 100 2.1 2001 12.4 1.2 – 34.9 100 0.9 2002 13.1 2.9 – 48.6 91.7 1.4 2003 12.3 1.8 – 39.5 91.7 0.6 2004 12.8 2.6 – 40.8 91.7 0.8

ICF International 

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06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Meteorological Representativeness and Episode Selection Exercises

(e) Pensacola

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 12.8 1.2 – 52.5 2000 12.6 3.4 – 45.5 100 2.0 2001 13.1 2.6 – 52.5 100 0.9 2002 13.2 3.3 – 40.7 100 1.4 2003 12.5 1.6 – 41.7 90.9 1.1 2004 12.4 1.2 – 40.7 100 0.9
(f) Outlying Landing Field

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.8 0.7 – 130.9 2000 12.4 0.7 – 130.9 100 2.6 2001 11.1 2.4 – 32.9 100 1.1 2002 11.3 2.3 – 38.3 100 1.8 2003 11.5 2.2 – 32.6 100 1.7 2004 11.7 2.3 – 44.8 100 1.6
(g) Gulfport

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.4 0.3 – 44.0 2000 11.0 0.3 – 44.0 100 1.4 2001 11.4 2.3 – 41.4 100 1.2 2002 11.4 2.8 – 31.9 100 1.3 2003 11.6 2.7 – 30.1 100 0.6 2004 11.5 1.6 – 43.5 100 1.6

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(h) Oak Grove

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.8 1.5 – 90.1 2000 11.9 2.5 – 41.4 100 2.2 2001 11.8 2.3 – 90.1 100 0.7 2002 11.4 2.2 – 67.1 100 1.3 2003 11.5 1.5 – 43.9 100 0.8 2004 11.6 2.2 – 37.2 100 0.6



### For the inland sites the weighted average PM 2.5 

### values tend to be highest for 2000, lower for 2001-2003, and then high again for 2004. For the coastal sites, the values are fairly similar for all years, with some variations. The range in PM 2.5 

### indicates that the highest values were recorded early during the five-year period. Figure 4-7 shows the year by year tendencies in weighted average PM 2.5 

### and daily maximum 24-hour average PM 2.5 

### for each of the SEARCH sites. For most sites, there is no apparent trend in the meteorologically adjusted (weighted average) values. The maximum values follow the tendency described above.

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Figure 4-7. Year-by-Year Tendencies in Weighted Average PM 2.5 and Daily Maximum 24-hour Average PM 2.5 for Each of the SEARCH Sites. (a) Atlanta



### Weighted Average PM2.5: Atlanta

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Atlanta

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(b) Yorkville



### Weighted Average PM2.5: Yorkville

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Yorkville

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(c) Birmingham



### Weighted Average PM2.5: Birmingham

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Birmingham

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(d) Centreville



### Weighted Average PM2.5: Centreville

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Centreville

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(e) Pensacola



### Weighted Average PM2.5: Pensacola

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Pensacola

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(f) OLF



### Weighted Average PM2.5: OLF

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: OLF

0 20 40 60 80 100 120 140

2000 2001 2002 2003 2004ugm-3

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(g) Gulfport



### Weighted Average PM2.5: Gulfport

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Gulfport

0 20 40 60 80

2000 2001 2002 2003 2004ugm-3

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(h) Oak Grove



### Weighted Average PM2.5: Oak Grove

0 5 10 15 20 25

2000 2001 2002 2003 2004ugm-3



### Daily Maximum PM2.5: Oak Grove

0 20 40 60 80 100 120

2000 2001 2002 2003 2004ugm-3



### With few exceptions, the key bins for PM 2.5 

### are represented for all of the years. The distribution error ranges from approximately 0.5 to 2.5 and quantifies how well the frequency distribution of days among the bins matches that for the full baseline period. The distribution error over all key bins is lowest for 2002 for Atlanta, Yorkville, and Birmingham. Overall, 2000 is the year with the least representative distribution.
For Atlanta (Table 4-3a), the weighted PM 2.5 

### value for 2002 is close to the average for the full baseline period. The range reflects a lower maximum value than for the other years and not all key bins are represented. Nevertheless, the distribution error is the lowest among all years considered.
For Birmingham (Table 4-3c), the weighted average PM 2.5 

### value for 2002 is also close to the average for the full baseline period, and the range is typical for the middle years. The distribution error is the lowest overall.
For the SEARCH sites, 2002 does not include some of the higher values of the other years but other indicat ors suggest that this is a representative year for the SEARCH sites.

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## 4.3. Selection Subset Episodes for M odel-Based Sensitivity Analysis
The CART results were also used in selecting subset periods of 2002 for PM 2.5 

### modeling and sensitivity analysis. The episode selection methods are presented in this section and the key question of “How well do subset modeling periods chosen by VISTAS for emission sensitivity analysis capture the range of relationships between meteorology and air quality for each site of interest and for the VISTAS region?” is examined.



## 4.3.1. Episode Selection
The goal of this exercise was to identify two approximate month-long subset periods of 2002 to represent the conditions and concentration levels associated with high PM 2.5 

### events in as many areas as possible throughout the VISTAS region. The two periods were also to represent both winter and summer types of regimes. The primary focus of this exercise was PM 2.5 

### ; however, information about ozone was also included in the final stages of the analysis. Because the selected episode periods were potentially to be used for PM 2.5 

### modeling of urban areas, we considered only the results for the STN and SEARCH sites. The episode selection methodology is outlined below.
First we prepared color-coded charts of daily PM 2.5 

### concentrations for each STN and SEARCH site and identified (primarily visually) winter and summer periods with a range of high and low concentrations for as many sites as possible. We also used the episode selection tool to identify periods that sample a range of key conditions for selected groups of areas.
We then input these dates into the CART-based meteorological characterization tool and used the summari es provided by the tool to assess and compare the representativeness of the periods with respect to frequent (key) meteorological conditions, annual average PM 2.5 

### (and ozone) concentrations, and speciation. We considered all of the VISTAS STN and SEARCH areas, but gave more attention to those with the higher PM 2.5 

### design values.
The analysis components included several characterization metrics that focused on how well the weighted annual average and range of PM 2.5 

### concentrations represent these same metrics for the full baseline period, and the degree to which the key PM 2.5 

### bins are represented by the identified periods. We also compared the compositional averages for the identified days with those for the baseline periods. Finally, we examined the range and frequency of occurrence of wind directions at the surface and 850 mb levels relative to a longer period of record.
The winter period was selected first. From three candidate winter periods, the period 19 Nove mber–20 December 2002 was selected to best capture the PM 2.5 

### concentrations (especially for the sites with the higher PM 2.5 

### design values) and the key high PM 2.5 

### CART bins. The wind directions for this period also represented the average wintertime distribution slightly better than the other two candidates, for several locations.
Seven candidate summertime periods were then reviewed with respect to representing the

summer con ditions for the baseline period and complementing the selected wintertime period in representing the annual range of conditions of the baseline period. The summertime period 3 June–10 July 2002 was selected. When this period is combined with the wintertime period, optimum representation of the key bins (for all categories) and the distribution of days among the key bins are achieved. The distribution of wind directions for high PM days is also representative of the longer period. Finally, the period includes high ozone days for the areas

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### with the higher design values. This exercise demonstrates the use of the episode selection and meteorological characterization tool to identify episodic periods for air quality modeling.



## 4.3.2. Episode Representativeness

The characteristics, attributes, and limitati ons of the episode periods are examined and compared in this section. Although the episode selection only considered the STN and SEARCH sites, we examine the representativeness of the selected episodes for the IMPROVE, STN and SEARCH sites.


## IMPROVE Sites
Table 4-4 summarizes and compares 2000-2004, 2002, and the combined episode periods for the IMPROVE sites. The summary metrics are the same as those for Table 4-1. The weighted extinction coefficients and average concentrations provide information on how well 2002 represents average conditions for the baseline period (as discussed earlier in this section) and then how well the subset episodes represent the 2002 annual period, when the days are weighted to best represent the expected frequency of occurrence of the different types of conditions. For many of the sites, good to very good agreement is achieved between the 2002 and episode values. The range in PM 2.5 

### concentration for the episode days indicates that, for many of the sites, the episode days include the peak days for 2002 (that is, the upper end of the range is the same as for 2002). The episodes contain 71 days, and as expected, do not always include days from all of the key bins. However, considering all sites, between 70 and 100 percent of the key bins are captured for both visibility and PM by the episode days – this varies by site. As expected, the distribution errors are larger for the episode periods, indicating that the episodes do not necessarily sample the various types of days with the frequency that is typical of the longer periods. For several of the coastal sites, including Cape Romain, Chassahowitzka, Everglades, and Swanquarter, the distribution error for the episode periods is not that much greater than that for 2002. Further inland, where more variable meteorology may lead to larger differences between the conditions described by the CART bins, the difference in the errors tends to be greater.

Table 4-4. Summary of Visibility, PM 2.5 and Meteorological Characteristics for 2000-2004, 2002, and the 2002 VISTAS Episodic An alysis Periods: IMPROVE Sites. (a) Breton

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 78.5 7.6 1.2 – 21.5 100 2002 71.2 6.7 1.8 – 16.4 100 1.6 100 0.7 Episodes 69.1 6.1 3.8 – 8.5 81.8 3.3 77.8 3.4

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(b) Brigantine

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 95.6 9.7 1.4 – 39.2 2002 93.6 9.6 1.4 – 36.5 100 0.9 100 1.7 Episodes 101.1 9.5 3.6 – 36.5 81.3 2.3 100 5.4

(c) Cadiz

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 107.4 11.0 0.6 – 31.3 2002 107.4 11.1 4.1 – 30.2 100 1.1 100 1.0 Episodes 107.5 10.3 4.1 – 30.2 85.7 4.3 100 4.1
(d) Caney Creek

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 83.0 9.0 0.3 – 28.3 2002 92.1 8.9 0.5 – 28.3 100 0.9 100 1.0 Episodes 93.4 7.9 0.5 – 26.2 86.7 1.6 90 2.8
(e) Cape Romain

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 82.0 8.6 1.1 – 30.1 2002 79.8 8.0 1.1 – 22.6 100 1.3 100 1.1 Episodes 79.1 7.3 1.4 – 16.4 85.7 2.4 90.9 2.2

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(f) Chassahowitzka

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 89.5 8.7 2.1 – 24.7 2002 86.5 8.2 2.5 – 17.7 100 1.1 100 1.6 Episodes 87.3 7.7 3.1 – 12.6 91.7 2.7 100 1.8
(g) Cohutta

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 95.6 10.7 1.2 – 44.4 2002 95.4 10.6 2.2 – 44.4 100 1.2 100 1.3 Episodes 90.8 10.6 3.9 – 44.4 100 2.4 87.5 2.6
(h) Dolly Sods

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 86.0 9.4 0.4 – 37.2 2002 79.1 8.7 1.3 – 37.2 100 1.0 100 0.9 Episodes 81.6 8.2 2.1 – 37.2 100 3.3 100 4.9
(i) Everglades

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 63.4 6.5 1.1 – 34.4 2002 61.8 6.3 1.4 – 23.4 100 1.0 100 1.3 Episodes 69.1 6.6 1.4 – 23.4 81.8 2.5 88.9 1.9

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(j) Great Smoky Mountains

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 85.7 10.1 0.5 – 35.6 2002 78.6 9.8 1.7 – 27.9 100 1.1 100 0.7 Episodes 72.1 9.2 2.0 – 25.4 71.4 2.3 100 2.5
(k) James River Face

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 102.1 10.9 0.5 – 31.5 2002 101.0 11.7 3.5 – 31.5 100 1.3 100 1.1 Episodes 92.1 11.2 4.5 – 31.5 70.0 2.4 88.9 2.5
(l) Linville Gorge

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 80 8.9 0.3 – 29.2 2002 72.4 8.8 1.6 – 27.1 92.3 1.7 100 1.0 Episodes 55.8 8.3 3.1 – 21.6 76.9 4.2 88.9 2.3
(m) Mammoth Cave

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 110.0 11.7 2.0 – 44.6 2002 104.1 11.5 3.8 – 34.0 100 0.8 100 1.4 Episodes 100.8 10.9 6.1 – 25.3 91.7 3.2 88.9 4.4

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(n) Mingo

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 94.7 11.5 2.4 – 50.0 2002 80.9 9.1 3.1 – 15.4 100 1.2 100 2.4 Episodes NA NA NA NA NA NA NA
(o) Okefenokee

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 86.7 9.1 2.2 – 42.9 2002 88.9 9.5 2.9 – 30.1 100 1.0 100 0.7 Episodes 80.2 8.3 2.9 – 28.3 100 2.3 90 2.6
(p) Shenandoah

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 95.2 9.3 0.1 – 33.9 2002 99.0 9.6 0.8 – 29.8 100 2.2 100 1.8 Episodes 88.0 8.3 2.7 – 26.1 100 3.9 88.9 3.5
(q) Shining Rock

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 75.1 7.8 0.2 – 57.6 2002 65.0 8.1 0.4 – 23.2 100 1.3 100 1.2 Episodes 47.8 10.8 2.8 – 21.0 81.8 3.6 77.8 1.9

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(r) Sipsey

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 100.8 11.1 1.6 – 36.3 2002 95.9 10.8 4.4 – 29.0 100 1.2 100 1.2 Episodes 87.6 10.5 5.5 – 20.8 91.7 2.5 100 4.1
(s) St. Marks

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 77.9 8.5 1.5 – 31.9 2002 79.2 8.1 2.3 – 21.4 100 1.0 100 1.7 Episodes 64.5 6.8 2.4 – 15.7 91.7 3.2 77.8 3.8
(t) Swanquarter

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000– 2004 81.8 7.9 0.6 – 27.0 2002 79.3 8.1 1.8 – 22.2 100 1.3 100 1.9 Episodes 65.8 7.0 2.2 – 22.2 83.3 2.3 75 2.4
(u) Upper Buffalo

Period Weighted Average Extincti on Coefficient

(Mm -1 ) Weighted Average

PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key Visibility

Bins Represented (%

) Distribution Error Over

All Key Visibility Bins (%) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 73.4 8.6 0.1 – 30.0 2002 79.2 9.2 1.7 – 27.1 100 1.0 100 1.6 Episodes 78.2 8.3 3.5 – 26.0 92.3 2.8 88.9 3.2



### Some additional plots are provided to characterize the overall representativeness of the urbanPM 2.5 

### -based episode periods for selected example sites, namely Cape Romain, Great Smoky

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### Mountains, and Mammoth Cave. Figure 4-8 compares the average concentration of the PM species for the three time periods, 2000-2004, 2002, and 1 June – 10 July and 19 November – 19 December, 2002 (the combined subset epi sode periods). Figure 4-9 examines and compares the distribution of surface wind direction, by wind direction quadrant, for the three sets of dates.

Figure 4-8. Comparison of Species Concentrations ( μ gm -3 ) for Sulfate (SO4), Nitrate (NO3), Organic Carbon (OC), Elemental Carbon (EC) and Ammonium (NH4) for 2000-2004, 2002, and 2002 VISTAS Episode Periods: IMPROVE Sites. (a) Cape Romain



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

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(b) Great Smoky Mountains



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

(c) Mammoth Cave



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

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Figure 4-9. Distribution of Surface Wind Direct ions by Quadrant for 2000-2004, 2002, and 2002 VISTAS Episode Periods: IMPROVE Sites. (a) Cape Romain

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

(b) Great Smoky Mountains

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

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(c) Mammoth Cave

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes



### For Cape Romain (Figure 4-8a), the average concentrations for all species are very similar for all three periods. The su bset periods match the averages for 2002 very closely. The distributions of wind directions (Figure 4-9a) for the three periods also agree very well, with fewer occurrences of northeasterly winds for the episodes, than the longer periods.
For GSM (Figure 4-8b), both 2002 and the episodes have slightly higher sulfate concentrations than the full baseline period, and 2002, on average, has slightly lower organic carbon. The distributions of wind directions (Figure 4-9b) for the three periods agree quite well. 2002 has a higher percentage of days with southeasterly winds and a lower percentage of days with southwesterly winds than the full period. The distribution for the episode periods follows that for 2002 fairly closely.
For Mammoth Cave (Figure 4-8c), the episode days have, on average, slightly lower sulfate and slightly high er nitrate and organic carbon concentrations than both 2002 and the full baseline period, which are very well matched in terms of average concentrations. The episodes also have a greater percentage of days with southeasterly winds and a lesser percentage of days with northwesterly winds than the longer periods (Figure 4-9c).



## STN Sites
Table 4-5 summarizes and compares 2000-2004, 2002, and the combined episode periods for the STN sites. The summary metrics are the same as those for Table 4-2. The weighted average PM 2.5 

### concentrations provide information on how well 2002 represents average conditions for the baseline period (as discussed earlier in this section) and then how well the subset episodes represent the 2002 annual period, when the days are weighted to best represent expected frequency of occurrence of the different types of conditions.

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Table 4-5. Summary of PM 2.5 and Meteorological Characteristics for 2000-2004, 2002, and the 2002 VISTAS Episodic Analysis Periods: STN Sites. (a) Birmingham

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 18.8 0.4 - 71.3 2002 17.8 4.2 - 47.8 100 1.1 Episodes 18.8 7.1 – 41.5 100 3.5
(b) Charlotte

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 2.3 – 45.2 2002 14.4 3.2 – 45.2 100 1.6 Episodes 14.7 3.8 – 34.5 100 3.2
(c) Chattanooga

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 15.6 2.5 – 48.6 2002 14.5 4.2 – 31.3 100 1.1 Episodes 13.5 4.3 – 31.3 90 3.9
(d) Greenville-Spartanburg

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.8 0.5 – 51.5 2002 14.9 1.5 – 49.8 100 1.2 Episodes 15.7 4.5 – 37.3 42.3 1.9

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(e) Hickory

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 15.8 2.6 – 40.7 2002 15.5 4.5 – 40.7 100 0.9 Episodes 15.3 5.8 – 33.5 100 4.2
(f) Huntington-Ashland

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 0.6 – 54.5 2002 14.9 3.0 – 46.8 100 1.0 Episodes 13.7 3.0 – 46.8 100 3.7
(g) Jackson

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 13.7 1.8 – 45.3 2002 13.0 1.8 – 45.3 100 2.0 Episodes 11.9 4.8 – 24.8 77.8 2.9
(h) Kingsport-Bristol

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.8 1.9 – 49.2 2002 14.0 2.6 – 37.5 100 0.8 Episodes 13.8 4.9 – 34.4 90.9 3.4

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(i) Louisville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.1 3.3 – 100.6 2002 17.7 4.1 – 100.6 100 1.0 Episodes 18.2 7.1 – 100.6 91.7 3.9
(j) Macon

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 16.1 2002 15.2 4.3 – 41.0 100 1.2 Episodes 13.6 5.2 – 29.3 88.9 3.0
(k) Memphis

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.2 1.1 – 50.0 2002 13.8 3.6 – 49.4 91.7 0.8 Episodes 14.5 3.9 – 36.4 75 3.0
(l) Montgomery

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.7 0.4 – 52.1

2002 14.9 3.5 – 39.4 100 0.7
Episodes 13.9 6.5 – 28.9 90 2.4

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(m) Nashville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.9 0.2 – 42.3 2002 14.6 2.6 – 39.8 100 1.1 Episodes 15.1 6.6 – 39.8 81.8 3.1
(n) Raleigh

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.1 2.3 – 52.8 2002 13.3 2.3 – 43.8 91.7 1.6 Episodes 13.5 4.3 – 43.8 91.7 2.2
(o) Richmond

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.2 0.0 – 50.5 2002 13.0 1.2 – 50.5 100 1.0 Episodes 13.9 2.8 – 50.5 92.3 3.7
(p) Savannah

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 14.0 3.2 – 55.3 2002 12.8 3.9 – 30.1 100 1.5 Episodes 11.9 5.7 – 20.3 88.9 2.0



### Overall good to very good agreement is ac h ieved between the 2002 and episode values, and the weighted average concentration for the episode days is within approximately 1 μ gm -3 

### of the 2002 average value for many of the sites. For several sites, the episode days include the peak

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### days for 2002 (the upper end of the range is the same as for 2002). Considering all sites, between 42 and 100 percent of the key bins are captured by the episode days. The distribution errors are larger for the episode periods, as the episodes do not necessarily sample the various types of days with the frequency that is typical of the longer periods.
Figure 4-10 compares the average concentration of the PM species for 2000-2004, 2002, and the combined episode p eriods for four example sites: Charlotte, Chattanooga, Louisville, and Macon. Figure 4-11 examines and compares the distribution of surface wind direction, by wind direction quadrant, for the three sets of dates, for these same sites.

Figure 4-10. Comparison of Species Concentrations ( μ gm -3 ) for Sulfate (SO4), Nitrate (NO3), Organic Carbon (OC), Elemental Carbon (EC) and Ammonium (NH4) for 2000-2004, 2002, and 2002 VISTAS Episode Periods: STN Sites. (a) Charlotte



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

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(b) Chattanooga



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

(c) Louisville



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

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(d) Macon



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

Figure 4-11. Distribution of Surface Wind Direct ions by Quadrant for 2000-2004, 2002, and 2002 VISTAS Episode Periods: STN Sites. (a) Charlotte

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

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(b) Chattanooga

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

(c) Louisville

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

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(d) Macon

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes



### Average concentrations for sulfate and organic carbon are higher for 2002, compared to the baseline per iod, and even higher for the episode periods for Charlotte (Figure 4-10a). There area also differences in the distribution of wind directions among the three periods (Figure 4- 11a). Both 2002 and the episode periods show a lesser proportion of southwesterly winds than the baseline period. The 2002 annual period makes up for this with winds from the northeast, and the episodes make up for this with winds from the southeast.
For Chattanooga (Figure 4-10b), the episode periods have higher average species concentratio ns for sulfate, organic carbon, and, to some extent, nitrate and ammonium, than the longer periods. They are also characterized by a greater proportion of southeasterly and a less proportion of southwesterly winds than the longer periods (Figure 4-11b).
Similarly, for Louisville (Figure 4-10c), the episode periods have higher average species concentratio ns for all species than the longer periods. In this case, a lower fraction of the days have northwesterly winds (Figure 4-11c).
For Macon (Figure 4-10d), 2002 is characterized by higher average sulfate than the baseline period and t he episode days have higher organic carbon concentrations than both 2002 and the full baseline period. The episode days have a great er percentage of days with northwesterly winds compared to the longer periods (Figure 4-11d). Differences in the wind direction distributions between 2002 and the full baseline period are relatively small.



## SEARCH Sites
Table 4-6 summarizes and compares 2000-2004, 2002, and the combined episode periods for the STN sites. The summary metrics are the same as those for Table 4-2.

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Table 4-6. Summary of PM 2.5 and Meteorological Characteristics for 2000-2004, 2002, and the 2002 VISTAS Episodic Analysis Periods: SEARCH Sites. (a) Atlanta (Jefferson St.)

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 16.6 1.1 – 66.1 2002 16.3 3.7 – 40.2 91.7 0.8 Episodes 17.2 5.0 – 40.2 91.7 3.0
(b) Yorkville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 13.6 0.7 – 65.2 2002 13.2 2.6 – 34.8 100 0.6 Episodes 13.6 3.8 – 34.8 91.7 1.9
(c) Birmingham

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.9 2.8 – 75.2 2002 17.5 3.9 – 45.3 100 0.9 Episodes 18.5 5.5 – 41.2 90.9 3.0
(d) Centreville

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 12.9 1.2 – 54.4 2002 13.1 2.9 – 48.6 91.7 1.4 Episodes 11.8 4.1 – 39.7 75 2.7

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(e) Pensacola

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 12.8 1.2 – 52.5 2002 13.2 3.3 – 40.7 100 1.4 Episodes 12.1 3.4 – 31.5 90.9 4.2
(f) Outlying Landing Field

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.8 0.7 – 130.9 2002 11.3 2.3 – 38.3 100 1.8 Episodes 10.4 3.6 – 21.0 77.8 3.7
(g) Gulfport

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.4 0.3 – 44.0 2002 11.4 2.8 – 31.9 100 1.3 Episodes 10.0 3.3 – 18.9 72.7 2.9
(h) Oak Grove

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 11.8 1.5 – 90.1 2002 11.4 2.2 – 67.1 100 1.3 Episodes 10.1 3.0 – 27.5 63.6 2.3



### The weighted average PM 2.5 

### concentrations are quite similar for all three sets of dates, and the weighted average concentration for the episode days is within approximately 1 μ gm -3 

### of the 2002 average value for all of the sites. The range in PM 2.5 

### concentration is similar for 2002 and

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### the episode days for the inland sites, but not for the coastal sites. Considering all sites, between 64 and 100 percent of the key bins are captured by the episode days. The distribution errors are larger for the episode periods, as the episodes do not necessarily sample the various types of days with the frequency that is typical of the longer periods.
Figure 4-12 compares the average concentration of the PM species for 2000-2004, 2002, and the combined episode periods for tw o of the SEARCH sites: Atlanta and Birmingham. Figure 4- 13 examines and compares the distribution of surface wind direction, by wind direction quadrant, for the three sets of dates, for these same sites.

Figure 4-12. Comparison of Species Concentrations ( μ gm -3 ) for Sulfate (SO4), Nitrate (NO3), Organic Carbon (OC), Elemental Carbon (EC) and Ammonium (NH4) for 2000-2004, 2002, and 2002 VISTAS Episode Periods: SEARCH Sites. (a) Atlanta



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

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(b) Birmingham



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3



### 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

2000-2004 2002 Episodesμ g m-3

Figure 4-13. Distribution of Surface Wind Direct ions by Quadrant for 2000-2004, 2002, and 2002 VISTAS Episode Periods: SEARCH Sites. (a) Atlanta

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes

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(b) Birmingham

0 10 20 30 40 50 60

NE SE SW NW

Wind Direction QuadrantPercent of Days (%)

2000-2004
2002 Episodes



### For Atlanta (Figure 4-12a), the average concentrations for all species are very similar for 2002 and the full baseline period. The episode days are characterized by higher sulfate and organics than 2002. The plot of the distribution of wind directions (Figure 4-13a) shows that all three periods are similar with regard to the predomi nantly northwesterly winds, the distribution among the other three quadrants differs.
For Birmingham (Figure 4-12b), episodes have higher sulfate concentrations than both 2002 and the full baseline period. Organic carbon is lower than the baseline for 2002 and higher than the baseline for the episodes. The distribution of wind directions (Figure 4-13b) for 2002 and the full baseline period are fairly similar. The epis ode days have a higher percentage of days with northeasterly winds and a lower percentage of days with southwesterly winds than the longer periods. 

## 4.4. Calculation of Meteorologi cally-Based Weighting Factors
The CART results and tool were also used in the calculation of weighting factors related to regional haze and PM 2.5 

### for the modeled days. The weighting factors are intended to be applied to the VISTAS atmospheric modeling results so that they can better represent the baseline period for the projection of future air quality related values. Weights were calculated for each site based on 1) similarities between the modeled days and the regulatory Best and Worst days (for regional haze) and 2) the frequency of occurrence of the conditions associated with the modeled days during the 2000-2004 baseline period (for regional haze and PM 2.5 

### ). Additional detail on the calculation of the weighting factors is provided below.
The weighting factors for the modeled days can be used to weight each day’s contribution to the average relative reductio n factor that is used to estimate future year air quality. There are a number of different ways in which the weighting factors can be used. For illustrative purposes, we provide a simple example. Consider the quarterly relative reduction factor (RRF) for a species, which is defined as the ratio of t he quarterly average future-year to base-year

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### simulated species concentration. Assume that the quarterly average value is based on two modeled days.
The unweighted RRF is equal to (C1 f 

### + C2 f 

### )/(C1 b 

### + C2 b 

### ) where C1 and C2 are the simulated concentrations for days 1 and 2, and the subscripts f and b refer to the future and base scenarios.
If the days are assigned weighting factors of w1 and w2, the weighted RRF becomes (w1

⋅ C1 f 

### + w2

⋅ C2 f 

### )/(w1

⋅ C1 b 

### + w2

⋅ C2 b 

### ).
The weighting factors are available in Excel format.



## 4.4.1. Annual Weighting Factors for Regional Haze
Two approaches were used to calculate the weighting factors for regional haze. Both relied on the identification of the 20 percent “Best” and “Worst” visibility days for the period 2000-2004, using the IMPROVE methodology in which extincti on coefficient is calculated as discussed in Section 2 of this report but using a monthly average f(rh) rather than a daily f(rh), as applied in this study. Only days with data were considered eligible for weighting. Days with data that are similar to one or more of the IMPROVE-method Best or Worst days (also referred to as the regulatory Best and Worst days) were assigned weighting factors. A day was considered to be similar to a Best or Worst day if it was assigned to the same CART bin as a Best or Worst day. Weighting factors were calculated separately for Best days and Worst days, and the set of days representing Best days is mutually exclusive fr om the set of days representing Worst days.
In the first approach, a weighting factor was assigned to each similar day based on both the overall frequency of occurrence of meteorological conditions (the total number of days in the CART bin) as well as the number of regulatory Best or Worst days in each bin.
In the second approach, the weighting factors were based only on the number of Best or Worst days in each bin. 

## Meteorological Frequency and Best /Worst Based Weighting Factors
We calculated weighting factors for each of the 21 IMPROVE sites for all 2002 dates for which there were valid visibility data for the site in question. Weighting factors for use in the Best days and Worst days assessments were calculated separately.
In calculating the weighting factors, we relied on the CART analysis results and used the bins and the number of days within each bin to define the meteorological and air quality conditions and their frequency of occurrence. Weights were assigned to each bin based on the total number of days in the bin and the number of Best (or Worst) days in the bin from a list of the 20% Best (B) (or 20% Worst (W)) days provided by VISTAS. The process consists of seven steps, as follows:
1) Each CART bin containing one or more B (or W) days is identified and the number of B (or W) days in the bin is counted (#B (or #W)).
2) Each CART bin is assigned a weight equal to the total number of days in the bin divided by the total nu mber of days included in the CART analysis (T/TT).

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### 3) Each CART bin containing one or more B (or W) day is assigned a second weighting factor equal to #B (or #W) divided by the total number of B (or W) days included in the analysis (B/TB (or W/TW)).
4) Each bin containing one or more of the selected days is identified and a bin weight (binwt) is calculated as the product of the two weighting factors above, T/TT and B/TB (or W/TW), divided by the sum of each term over all bins represented by one or more selected days.
5) Binwt is then normalized to account for unrepresented bins, giving an adjusted bin weight (adjbinwt). For all bins containing at least one B (or W) day and at least one selected day, adjbinwt sums to 1.
6) Adjbinwt is divided by the number of selected days within each bin to give the final weighting factor for th at bin (Day Wt).
7) Day Wt is assigned to the relevant dates based on each date’s bin classification.

Days were only assigned weights if the extinction coefficients were within the ranges appropriate to the Best or Worst classification categories. For the Best days, these are Categories 1 and 2 (Category 1 represents the 20 percent best days using daily extinction and f(rh) values; Category 2 was also considered). For the Worst days, these are Categories 3, 4, and 5 (Categories 4 and 5 combined represent the 20 percent worst days using daily extinction and f(rh) values and Category 3 is the neighboring category). For bins containing both B and W days, certain days were assigned factors to represent Best days and other days were assigned factors to represent Worst days.
The weighting factors accommodate the use of more than just the Best and Worst days in the future projection of regio nal haze by including si milar days to the Best and Worst days in the calculations. The weighting factors for the Best and Worst days only provide an improved representation of the frequency of occurrence of the conditions associated with the Best and Worst days, considering the full baseline period. 

## Best/Worst Only Based Weighting Factors
This is a simplified version of the approach described in the previous section. It considers only the number of Best or Worst days in a bin. Again, we calculated weighting factors for each of the 21 IMPROVE sites for all 2002 dates for which there were valid visibility data for the site in question. Weighting factors for use in the Best days and Worst days assessments were calculated separately
In calculating the weighting factors, we relied on the CART analysis results to identify days with similar conditions to the r egulatory Best and Worst days. Weights were assigned to each bin based on the number of B (or W) days in the bin from a list of the 20% Best (B) (or 20% Worst (W)) days provided by VISTAS. The process consists of five steps, as follows:
1) Each CART bin containing one or more B (or W) days is identified and the number of B (or W) days in the bin is counted (#B (or #W)).
2) Each CART bin containing one or more B (or W) day and one or more of the selected days is assigned a weight (binwt) equal to #B (or #W) divided by the total number of B (or W) days included in the analysis (B/TB (or W/TW)).

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### 3) Binwt is then normalized to account for unrepresented bins, giving an adjusted bin weight (adjbinwt). For all bins containing at least one B (or W) day and at least one selected day, adjbinwt sums to 1.
4) Adjbinwt is divided by the number of selected days within each bin to give the final weighting factor for th at bin (Day Wt).
5) Day Wt is assigned to the relevant dates based on each date’s bin classification.

As for the first approach, days were only assigned weights if the extinction coefficients were within the ra nges appropriate to the Best or Worst classification categories.
The weighting factors accommodate the use of more than just the Best and Worst days in the future projection of regio nal haze by including si milar days to the Best and Worst days in the calculations. These weighting factors take into account the number of Best and Worst days in a bin, however, they do not account for the overall frequency of occurrence of the conditions associated with the Best and Worst days, considering the full baseline period.



## 4.4.2. Episodic Weighting Factors for PM2.5

For PM 2.5 

### , weighting factors were calculated for each day of the two subset episode periods 1 June – 10 July and 19 November – 19 December, 2002, and for each STN and SEARCH site. These factors were based on the frequency of occurrence of the air quality/meteorological conditions represented by the episode day (based on the total number of days in the CART bin to which the day is assigned). All episode days with data were considered eligible for weighting.
In calculating the weighting factors, we relied on the CART analysis results and used the bins and the number of days within each bin to define the meteorological and air quality conditions and their frequency of occurrence. Weights were assigned to each bin based on the total number of days in the bin. The process consists of four steps, as follows:
1) Each CART bin containing one or more of the episode days is assigned a weight (binwt) equal to the total number of days in the bin divided by the total number of days included in the CART analysis (T/TT).
2) Binwt is normalized to account for unrepresented bins, giving an adjusted bin weight (adjbinwt). For all bins containing at least one episode day, adjbinwt sums to 1.
3) Adjbinwt for each bin is divided by the number of episode days within the bin to give the final weighting fa ctor for that bin (Day Wt).
4) Day Wt is assigned to the episode dates based on each date’s bin classification.

The weighting factors are expected to provide an improved re presentation of the frequency of occurrence of the conditions associated with the full baseline period.

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## 5. Key Findings and Implicatio ns for VISTAS Air Quality Modeling
The CART results provide insight into the relationships between meteorology, PM 2.5 

### , and visibility that are important to atmospheric modeling. Some key findings are summarized in this section. 

## CART Application
The application of CART included several sensitivity tests involving variations to the input dataset. Comparison of the results from the application of CART with and without PM 2.5 

### input data demonstrates that including PM 2.5 

### is important to classification a ccuracy. This result indicates that regional buildup and transport of fine particles and related precursor species influences regional visibility and PM 2.5 

### concentrations. Overall, better classification accuracy for PM 2.5 

### , compared to extinction coefficient, especially for the IMPROVE sites, indicates that the relationships between the input parameters and the characteristic parameter are better defined for PM 2.5 

### at these sites. This is possibly due the more complex role of moisture in determining light extinction – affecting both particle formation and the contribution of sulfate and nitrate particle species to light extinction. For both visibility and PM 2.5 

### , moisture is an important input to CART, and some information about moisture is needed in order to achieve good classification. We found daily average relative humidity to be the most effective form of the moisture parameter. 

## Parameter Importance
The CART results indicate that temperature, wind s peed, and relative humidity are key meteorological parameters that distinguish days with different fine particle mass and visibility values in the southeastern U.S. Considering visibility for the IMPROVE sites, the most important parameters include: relative humidity, prior day PM 2.5 

### concentrations at potential upwind monitoring sites, 850 mb temperature, surface temperature (reflecting seasonal differences), and wind speed (both near the surface and aloft). For PM 2.5 

### relative humidity is less important, but the list of important parameters is simila r. One key difference when comparing parameter importance for the inland, coastal, and mountain sites is that relative humidity and persistence (which, for coastal sites, represents a sea or gulf breeze) are more important for the coastal sites, compared to the inland and mountain sites. The temperature parameters are most important for the mountain sites. Wind direct ions are not used frequently enough in the CART trees to be considered important parameters to the overall classification, but they are often used near the end of the CART pathways to distinguish poor visibility and high PM 2.5 

### days.

For PM 2.5 

### for the STN and SEARCH sites, the most important parameters include: prior day PM 2.5 

### concentrations, 850 mb temperature, surface temperature, and wind speed (both near the surface and aloft). Relative humidity is also important for the coastal SEARCH sites.
These results vary by site, although, there are similarities among the sites within similar geographica l features. An assessment of the meteorological inputs for air quality modeling should emphasize good representation of these key parameters. 

## Site Groupings
The CART-derived parameter importance results were used to examine potential site groupings. We identified similarities in the important parameters for the analysis sites and attributed theseto similarities in the mechanisms influencing air quality at these sites. In general, the CARTderived groupings, which are based on parameter impor tance, are also supported by similarities in location and geography. The groupings for the IMPROVE sites are different for visibility versus PM 2.5 

### . These groupings may provide the basis for assessing model performance and

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### understanding the reasons for model performance problems. The grouping may also aid the interpretation of differences in the effectiveness of air quality measures across the monitoring sites and regions.



## CART Classification Results
CART also provides insight into the types of conditions that, based on their frequency of occurrence over a multi-year period, should be represented in an assessment of air quality responses to emissions changes. Poor visibility and high PM 2.5 

### days are grouped into bins that are characterized by different meteorological and prior-day air quality conditions. While there are similarities in the conditions that describe the key (most populated) bins, there are also some important differences that relate directly to source-receptor relationships and potentially control strategy effectiveness.
One of the more notable differences among the key poor visibility and high PM 2.5 

### bins is wind direction, especially surface wind direction. Wind direction, however, does not have a high parameter importance ranking. For many of the cases we examined, this is primarily because wind direction was used in the outermost (lowest) branches of the CART tree, such that days with similar features in many respects were separated into different bins (characterized by different extinction or PM 2.5 

### values) according to wind direction. Thus, wind direction can be important, but only in differentiating a small number of days. For several sites, large differences in average temperature among the key bins indicate that the regimes vary with season. Other differences include prior day PM 2.5 

### concentration, relative humidity, stability, and degree of persistence (indicating a sea or gulf breeze) for the coastal sites. The differences in the individual parameters combine to represent the different regimes, and there are multiple regimes associated with poor visibility and high PM 2.5 

### for all of the areas of interest. The differences among the key bins emphasize the need to include days that represent the different types of meteorological conditions that accom pany poor visibility and high PM events in any model-based air quality planning exercise.
The CART analyses also provide insight into PM 2.5 

### composition for different (key) types of poor visibility days and high PM 2.5 

### days. In general, analysis of the compositional characteristics for the key bins for the 20 percent haziest days for the IMPROVE sites within the VISTAS region indicates that, on average, ammonium sulfate and organic carbon are the two most important contributors to poor visibility and that their relative contributions vary by site, by bin, and with meteorology. For the inland IMPROVE sites, ammonium sulfate is the dominant contributor. For the coastal IMPROVE sites the contributions from ammonium sulfate and organic carbon on the poor visibility days are more comparable than at the interior sites. As for visibility, the high PM 2.5 

### concentration bins are distinguished from the lower concentration bins by higher sulfate and organic matter concentrations.
The STN compositional charts show a much larger proportional contribution from organic matter compared to those for th e IMPROVE sites, especially for the higher PM 2.5 

### bins. This is in part due to differences between the IMPROVE and STN measurement techniques for organic carbon. With the higher values for organics, the dominant species varies by bin, much more so than for the IMPROVE sites. These variations are attributable to differences in meteorology as well as regional pollutant transport.
The compositional charts for the PM 2.5 

### for the SEARCH sites also show a much larger proportional contribution from organics than the IMPROVE charts, especially for the higher

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### PM 2.5 

### bins. The relative ranking of the species contributions is similar to that for the STN sites. A comparison of the compositional averages for Birmingham using the STN and SEARCH data, shows that the organic matter and overall PM 2.5 

### values are higher in the STN data, but that the tendency for organic matter to be the dominant species appears in both sets of results for the more urban sites. 

## Simulation Period Representativeness
The 2002 annual simulation period includes days that capture the general meteorological characteristics associated with a range of visibility at the IMPROVE sites and represents well the typical frequency of occurrence of these conditions. However, somewhat lower than average concentrations and average extinction coefficients characterize 2002 for some sites. PM 2.5 

### values for the STN and SEARCH sites are also lower than average compared to other years within the baseline period. There is no apparent trend in the meteorologically adjusted (weighted average) annual average values of PM 2.5 

### for the STN and SEARCH sites.
While it is not expected that any single year will be typical or representative for all areas of the Class I and urban areas of interest, the CART results enhance the understanding of how well the 2002 simulation period represents each area and this will allow VISTAS to use and interpret their air quality modeling results appropriately.
Two subset episode periods from 2002, compri sing a total of 71 days, were selected to represent the conditions and concentration levels associated with high PM 2.5 

### events in as many areas as possible throughout the VISTAS region. These include a summer episode (1 June – 10 July) and a winter episode (19 November – 19 De cember, 2002). For many of the sites, the summer period includes the peak days for 2002. As expected, the episode periods, do not include days from all of the key bins for all sites. Considering all sites, between approximately 40 and 100 percent of the key bins are included by the episode days – this varies by site. The distribution errors are larger for the episode per iods, compared to the annual periods, indicating that the episodes do not sample the different regimes with the frequency that is typical of the longer periods. 

## Weighting Factors
The CART results and tool were also used in the calculation of weighting factors for both regional haze and PM 2.5 

### for the annual and episodic modeled days. The weighting factors were intended to improve the ability of the modeling results for 2002 and the subset periods to represent the full baseline period. The weighting factors for regional haze were calculated based on similarities between the modeled days and the regulatory 20% Best and 20% Worst days and the frequency of occurrence of the conditions associated with the modeled days during the 2000-2004 baseline period. The weighting factors for PM 2.5 

### were based on the frequency of occurrence of the meteorological conditions.
The weighting factors are intended to be applied to the VISTAS atmospheric modeling results so that they can better r epresent the baseline period for the projection of future air quality related values. In this manner, application of CART has improved the understanding of the conditions contributing to elevated PM 2.5 

### and poor visibility in the southeastern states and has provided the basis for the enhanced analysis and interpretation of atmospheric modeling results.

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## 6. References
ARA. 2005. SEARCH website available by At mospheric Research Associates at http://www.atmospheric-research.com/studies/SEARCH/
Brieman, L., J. H. Friedman, R. A. Olshen, and C. J. Stone. 1984. Classification and Regression Trees. Wadsworth, Belmont, California.
CIRA. 2005. VIEWS website available at, http://vista.cira.colostate.edu/views/
Cox, W. M. and S. Chu, 1996. Assessment of interannual ozone variation in urban areas from a climatological perspective. Atmos. Environ ., 30(14), 2615-2625.
Deuel, H. P., and S. G. Douglas. 1998. “Episode Selection for the Integrated Analysis of Ozone, Visibility, and Acid Deposition for the S outhern Appalachian Mountains.” ICF/Systems Applications International, Inc., San Rafael, California (SYSAPP-98/07r1). Douglas, S. G., J. B. Mangahas, A. B. Hudischewskyj, G. L. Glass, and W. S. Hartley, 2003. “Exa mination of Inter-Variable Relationships and Implications for Modeling Episode Selection Using the 1999/2000 SEARCH Database”, ICF/Systems Applications International, Inc., San Rafael, California (03-060).
Douglas, S. G., J. B. Mangahas, A. B. Hudischewskyj, and J. L. Haney, 2004. “The Developme nt of PM 2.5 

### Forecasting Tools for Selected Cities in the MARAMA Region,” ICF/Systems Applications International, 101 Lucas Valley Rd., Suite 260, San Rafael California 94903, (04-046).
Eder, B. K., J. M. Davis, P. Bloomfield, 1993. A characterization of the spatiotemporal variability of non-urban ozone con centrations over the eastern United States. Atmos. Environ

., 27A, 2645-2668.
EPA. 2001. Guidance for Demonstrating Attainment of Air Quality Goals for PM 2.5 

### and Regional Haze. Draft.
EPA, 2004. Procedures for Estimating Future PM2.5 Values for the CAIR Final Rule by Application of the (Revised) Speciat ed Modeled Attainment Test. Available at http:// www.epa.gov

. EPA. 2005. Aerometric Information Retrieval System database available at http:// www.epa.gov

. NCDC. 2005. National Climatic Data Center website available at http://www.ncdc.noaa.gov/oa/ncdc.html

. Regional Haze Regulations; Final Rule. 1999: Fe deral Register , 64, 35713-35774. Steinberg, Dan, and Phillip Colla. CART—Classification and /regression Trees. San Diego, CA: Salford Systems, 1997.

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## Appendix: Comparison of Resu lts for the STN and SEARCH Birmingham Sites
Two CART analyses were conducted for Birmingham. Both analyses used PM 2.5 

### data for the North Birmingham monitoring site. For the first analysis, the PM 2.5 

### data were based on STN measurements and the surface meteorological i nputs were based on data from the nearby NWS monitoring site. For the second analysis, the SEARCH data were used to prescribe both the PM 2.5 

### and surface meteorological inputs. In both cases, upper-air meteorological data from the nearby NWS measurement site were used. PM 2.5 

### data are available for both sites for the entire 2000-2004 period. The analysis using the SEARCH data includes one additional year of speciated data (for the year 2000). In this appendix, we compare the results and inferences for the two Birmingham analyses for PM 2.5


### . 

## Comparative Analysis

CART classification accuracy for PM 2.5 

### is very similar for the two analyses—78.5 percent for the STN analysis and 77.1 percent for the SEARCH analysis. The relative importance of the input parameters in constructing the CART classification tree is also very similar for the two analyses, as displayed in Figures A-1 and A-2. Prior-day PM concentrations, surface wind speed, prior-day 700 mb wind speed, relative humidity, and stability are, in order, the five most important parameters for the STN analysis. These same five parameters along with 850 mb wind speed are most important for the SEARCH analysis. The order of importance is roughly the same, with 850 mb wind speed surpassing relative humidity in relative importance for the SEARCH analysis.

Figure A-1. Parameter Importance for the CART PM 2.5 Analysis: Birmingham STN Site.

0 2 0 4 0 6 0 8 0 1 0 0 Clouds Avg 850 mb w ind direction

Avg 850 mb w ind speed Yesterday's 700 mb w ind direction (PM)

Yesterday's 700 mb w ind speed (PM) 700 mb height difference Stability Avg 850 mb temp Rain Max surface pressure Persistence Surface w ind direction

Surface w ind speed Relative humidity at noon Avg surface temp Regional avg of yesterday's max PM

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Figure A-2. Parameter Importance for the CART PM 2.5 Analysis: Birmingham SEARCH Site.

0 20 40 60 80 100 Clouds Avg 850 mb w ind direction

Avg 850 mb w ind speed Yesterday's 700 mb w ind direction (PM)

Yesterday's 700 mb w ind speed (PM) 700 mb height difference Stability Avg 850 mb temp Rain Max surface pressure Persistence Surface w ind direction

Surface w ind speed Relative humidity Avg surface temp Regional avg of yesterday's max PM



### A more detailed look at the CART classification trees confirms that analysis results are similar, with respect to the conditions leading to high PM 2.5 

### and, in CART terms, the high PM 2.5 

### classification bins. However, the CART tr ee developed using the SEARCH data has more bins than that developed using the STN data (32 versus 26).
The CART input data for the two analyses are summarized in Tables A-1 and A-2. These tables present the average value of each input parameter for each PM 2.5 

### classification category for the Birmingham STN and SEARCH datasets. The four PM 2.5 

### categories are defined by the 70, 90, and 97 percentile values of PM 2.5 

### mass, which are slightly different for the two sites. For the STN site, the ranges for Categories 1 through 4 are <22.5, 22.5-32.5, 32.5-40 and ≥ 40 μ gm -3



### . For the SEARCH site, the ranges are <20, 20-30, 30-37.5 and ≥ 37.5 μ gm -3



### .

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Table A-1. Summary of Average Input Paramete rs for Each CART Classification Category: PM 2.5 CART Analysis for the Birmingham STN Site. The ranges in PM2.5 for Categories 1 through 4 are as follows: <22.5, 22.5-32.5, 32.5-40 and ≥ 40 μ gm-3.
Category 1 Category 2 Category 3 Category 4
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 16.8 25.2 29.9 40.5 Yesterday's FM at Atlanta (μg/m 3 ) 16.9 22.1 24.8 31.1 Yesterday's FM at Memphis (μg/m 3 ) 12.9 17.7 19.8 25.1 Yesterday's FM at Nashville (μg/m 3 ) 13.3 18.5 20.9 24.7 Surface Meteorological Parameters Max. surface temperature (°C) 20.9 25.9 27.2 29.0 Min. surface temperature (°C) 10.9 14.0 14.4 15.2 Relative humidity (%) 70.4 66.5 63.4 62.3 Surface wind speed (ms -1 ) 2.5 1.5 1.2 0.9 Surface wind direction (degrees) 279 79 87 11 Persistence 0.8 0.8 0.7 0.7 Sea level pressure (mb) 1021 1021 1021 1022 Rainfall (inches) 0.2 0.1 0.0 0.0 Rain (# periods) 1.0 0.6 0.3 0.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 10.2 12.9 13.6 14.3 Temperature PM 850 mb (°C) 10.2 13.8 14.3 15.2 Stability at Birmingham (°C) -0.1 2.1 2.9 4.1 Geopotential height difference 700 mb at Birmingham (m) -1.2 5.3 0.6 2.8 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 12.7 8.1 7.9 6.0 Wind direction yesterday 700 mb at Birmingham (degrees) 265 302 322 339 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 8.9 5.6 5.0 3.9 Wind speed AM 850 mb at Birmingham (ms -1 ) 10.2 6.3 5.8 4.3 Wind speed PM 850 mb at Birmingham (ms -1 ) 8.9 5.9 5.5 3.7 Wind direction yesterday 850 mb at Birmingham (degrees) 255 345 10 32 Wind direction AM 850 mb at Birmingham (degrees) 264 261 258 284 Wind direction PM 850 mb at Birmingham (degrees) 271 238 90 315 Recirculation at Birmingham 0.0 0.1 0.1 0.3 Cloud average 1.8 1.6 1.6 1.6

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Table A-2. Summary of Average Input Paramete rs for Each CART Classification Category: PM 2.5 CART Analysis for the Birmingham SEARCH Site. The ranges in PM2.5 for Categories 1 thr ough 4 are as follows: <20, 20-30, 30-37.5 and ≥ 37.5 μ gm-3.
Category 1 Category 2 Category 3 Category 4
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 16.5 24.1 29.5 38.2 Yesterday's FM at Atlanta (μg/m 3 ) 16.7 21.6 23.7 30.8 Yesterday's FM at Memphis (μg/m 3 ) 12.7 17.0 19.9 23.3 Yesterday's FM at Nashville (μg/m 3 ) 13.2 17.5 20.6 23.4 Surface Meteorological Parameters Max. surface temperature (°C) 21.6 26.0 27.5 28.4 Min. surface temperature (°C) 11.5 14.3 13.9 14.7 Relative humidity (%) 70.9 66.4 63.0 62.3 Surface wind speed (ms -1 ) 1.8 1.3 1.0 0.8 Surface wind direction (degrees) 247 73 18 345 Persistence 0.8 0.8 0.7 0.7 Station pressure (mb) 998 998 998 1000 Rainfall (inches) 0.2 0.1 0.0 0.0 Rain (# periods) 1.0 0.6 0.4 0.3 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 10.2 12.5 13.0 13.9 Temperature PM 850 mb (°C) 10.3 13.2 13.9 14.7 Stability at Birmingham (°C) -0.3 2.1 3.1 3.5 Geopotential height difference 700 mb at Birmingham (m) -1.7 5.2 2.3 5.1 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 12.8 8.7 7.7 6.9 Wind direction yesterday 700 mb at Birmingham (degrees) 265 298 307 329 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 9.1 5.9 4.6 4.5 Wind speed AM 850 mb at Birmingham (ms -1 ) 10.3 6.6 5.6 5.0 Wind speed PM 850 mb at Birmingham (ms -1 ) 8.9 6.3 5.5 4.3 Wind direction yesterday 850 mb at Birmingham (degrees) 252 345 349 14 Wind direction AM 850 mb at Birmingham (degrees) 264 251 283 243 Wind direction PM 850 mb at Birmingham (degrees) 273 219 321 270 Recirculation at Birmingham 0.02 0.08 0.13 0.28 Cloud average 1.8 1.6 1.6 1.5



### The values and variations in the PM 2.5 

### related parameters among the classification categories are very similar for the two datasets.
The surface meteorological parameters are also very similar , with some exceptions for the surface wind directions. For the STN analysis, the Category 3 surface wind directions are easterly, on average. For the SEARCH analysi s, they are north-n ortheasterly. For t he STN analysis, the Category 4 surface wind directions are north-nort heasterly, on average. For the SEARCH analysis, they are north-northwesterly. In both cases, the surface winds have a northerly component on the highest PM 2.5 

### days. The westerly component is more pronounced in the SEARCH data summary.
The average values and tendencies for the upper-air parameters are also very similar, with the exception of t he 850 mb wind directions for the two highest categories. Again the SEARCH data summary shows a more pronounce westerly component at higher concentrations, especially at the

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### time of the evening sounding. The greater differences for wind direction compared to other parameters may be due, in part, to the uncertainties inherent in calculating an average wind direction (if the wind directions included in the averaging vary consider ably, the average may not be very meaningful).
From both analyses, we can summarize that high PM 2.5 

### for Birmingham is associated with high temperatures, high PM 2.5 

### on the previous day (local & potentially upwind sites), very low wind speeds near the surface and low wind speeds aloft, westerly wind components aloft and northerly wind components near the surface, and stable lapse rates.
Table A-3 compares the characteristics of key high PM 2.5 

### bins (Category 4) for the Birmingham STN and SEARCH analyses. Key bins are those containing the greatest number of correctly classified days. For ease of comparison, we focused on the key Category 4 bins (which contain subsets of the days with the highest concentrations). There are two key bins for the STN analysis, and three key bins for the SEARCH analys is. Due to different units between the two analyses, the row containing surface pressure was omitted from the combined table.

Table A-3. Summary of Average Input Parameters for Key Bins for CART Classification Category 4: PM 2.5 CART Analysis for Birmingham. The ranges in PM2.5 for Category 4 are ≥ 37.5 and ≥ 40 μ gm-3 for the STN and SEARCH analyses, respectively.

STN SEARCH
Bin 19 Bin 10 Bin 25 Bin 20 Bin 24
PM 2.5

Parameters Yesterday's FM at Birmingham (μg/m 3 ) 50.7 32.4 51.1 33.1 35.8 Yesterday's FM at Atlanta (μg/m 3 ) 37.6 25.6 39.3 23.5 25.5 Yesterday's FM at Memphis (μg/m 3 ) 28.3 22.2 27.8 18.2 20.8 Yesterday's FM at Nashville (μg/m 3 ) 27.7 19.5 28.9 18.7 17.9 Surface Meteorological Parameters Max. surface temperature (°C) 28.3 29.6 28.7 23.7 30.4 Min. surface temperature (°C) 14.5 14.6 14.0 10.2 15.9 Relative humidity (%) 63.1 61.6 58.6 64.8 58.4 Surface wind speed (ms -1 ) 0.7 0.3 0.5 0.5 0.7 Surface wind direction (degrees) 342 112 344 27 180 Persistence 0.8 0.5 0.7 0.6 0.7 Rainfall (inches) 0.0 0.0 0.0 0.0 0.0 Rain (# periods) 0.1 0.2 0.0 0.2 0.1 Upper-Air Meteorological Parameters Temperature AM 850 mb (°C) 13.6 14.6 13.5 11.3 15.0 Temperature PM 850 mb (°C) 14.4 15.9 14.1 12.3 15.9 Stability at Birmingham (°C) 4.5 4.0 4.6 2.9 4.3 Geopotential height difference 700 mb at Birmingham (m) 1.3 5.9 0.8 -14.7 30.1 Wind speed yesterday 700 mb at Birmingham (ms -1 ) 5.8 6.0 4.7 9.0 6.8 Wind direction yesterday 700 mb at Birmingham (degrees) 34 22 354 63 338 Wind speed yesterday 850 mb at Birmingham (ms -1 ) 3.6 4.5 2.9 7.0 2.8 Wind speed AM 850 mb at Birmingham (ms -1 ) 3.7 4.0 3.7 6.1 4.2 Wind speed PM 850 mb at Birmingham (ms -1 ) 2.9 3.2 2.9 4.9 3.7 Wind direction yesterday 850 mb at Birmingham (degrees) 34 22 37 27 90 Wind direction AM 850 mb at Birmingham (degrees) 270 45 270 180 270 Wind direction PM 850 mb at Birmingham (degrees) 270 180 360 207 243 Recirculation at Birmingham 0.4 0.2 0.5 0.0 0.4 Cloud average 1.5 1.5 1.4 1.6 1.6

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### For the STN analysis, the PM 2.5 

### concentration for Category 4 is greater than or equal to 40 μ gm 3 

### . Bin 19 is distinguished by a much higher prior-day value PM 2.5 

### concentration than Bin 10. The temperature and humidity characteristics of the two bins are similar. Both key bins are characterized by very low surface wind speeds, but different surface wind directions. Surface winds are southeasterly for Bin 10 and northwesterly for Bin 19. Upper-level wind speeds are lower (slightly) for Bin 19. Upper-level wind directions are northeasterly to southerly for Bin 10, and primarily westerly (on the current day) for Bin 19.
For the SEARCH analysis, the PM 2.5 

### concentration for Category 4 is greater than or equal to 37.5 μ gm -3 

### . Bin 25 is distinguished by a much higher prior-day value PM 2.5 

### concentration, and in this regard is similar to Bin 19 from the STN analysis. Bin 20 is distinguished by lower temperatures and slightly higher relative humidity than the other two SEARCH Category 4 bins. All three key bins are characterized by very low surface wind speeds, but surface wind directions differ among the three bins. Surface winds are northeasterly for Bin 20, southerly for Bin 24, and northwesterly for Bin 25. Upper-level wind speeds are lowest (in general) for Bin 25 and highest for Bin 20. Upper-level winds (current day) are southerly to southwesterly for Bin 20, westerly to southwesterly for Bin 24 and westerly to northerly for Bin 25.
If we compare the STN and SEARCH results, we find that Bin 19 from the STN analysis is similar in many respects to Bin 25 from t he SEARCH analysis. Key similarities (that also distinguish these bins from other Category 4 bins within their respective analyses) include very high PM 2.5 

### concentration on the prior day, northwesterly surface winds, low wind speeds aloft, and a transition from northeasterly to westerly winds aloft from the prior day to the morning of the current day. Bin 10 from the STN analysis has some features in common with Bin 20 of the SEARCH analysis and some features in common with Bin 24 of the SEARCH analysis. For example, Bins 10 (STN) and 24 (SEARCH) both have, on average, southerly wind components aloft during the afternoon hours of the current day. In some cases, the combined characteristics of SEARCH Bins 20 and 24 seem to represent Bi n 10 (STN). For example, the surface wind directions for SEARCH Bins 20 and 24 (northeas terly and southerly) when combined give a resultant wind direction similar to that for STN Bin 10 (southeasterly). It is interesting that for all of the Category 4 bins for both analyses, the prior-day 850 mb winds are from the northeast.
In summary, both CART analyses separate the days with very high prior-day concentrations and nort hwesterly to northerly winds from the remaining Category 4 days. The analysis using the SEARCH data appears to further divide the remaining days into two groups that are distinguished by temperature, relative humidity, surface and upper-air wind directions, and upper-air wind speeds. We have not explored the reasons for this additional and apparently meaningful segregation, but possible reasons include use of collocated surface meteorological data (for the SEARCH analysis) or that differences between the measurement techniques lead to the identification of different relationships between the PM 2.5 

### values and the other input parameters.
As part of our analysis, we also examined PM 2.5 

### composition for key bins corresponding to each Birmingham analysis. Figures A-3 and A-4 show the average composition for all key PM 2.5 

### bins for the STN and SEARCH analysis, respectively. Note that the scales are different.

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Figure A-3. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: Birmingham STN Site.

Birmingham Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00 24.00

4 (417) 8 (193) 24 (97) 2 (38) 25 (27) 6 (24) 11 (45) 26 (7) 19 (23) 10 (11)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4

Figure A-4. Average Elemental Carbon (EC), Nitrat e (NO3), Organic Matter (OM), and Sulfate (SO4) Concentrations ( μ gm -3 ) for Key PM 2.5 Bins for All CART Classification Categories: Birmingham SEARCH Site.

Birmingham SEARCH Key PM Bins: Component Averages

0.00 4.00 8.00 12.00 16.00 20.00

5 (568) 9 (213) 27 (137) 4 (53) 31 (47) 28 (24) 10 (22) 14 (29) 25 (24) 20 (9) 24 (7)

Class 1 Class 2 Class 3 Class 4 Bin No. (No. of Correctly Classified Days)Avg. Conc. (μg/m3)

EC
NO3
OM
SO4



### A comparison of the compositional averages for Birmingham using the STN (Figure A-3) and SEARCH (F igure A-4) data shows that the organic matter and overall PM 2.5 

### values are higher in the STN data, but that the tendency for organic matter to be the dominant species appears in both sets of results. For all key Category 4 PM 2.5 

### bins (for both the STN and SEARCH analysis), organic matter is the dominant species. However, the relative proportion of the species concentrations is different for each bin. This may be due to the differences in the average wind directions. As noted earlier, we found that all of the key bins are characterized by very low surface wind speeds, but, on average, the days within the bins have different wind directions. The similarities in the average parameter values noted earlier for Bins 19 (STN) and 25 (SEARCH) are not apparent in the relative values of the average species concentrations.

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### The compositional analysis results for Birmingham (especially for the SEARCH data) show a higher contribution of elemental carbon than for most other sites, and this may be related to emissions from the steel industry facilities that are located in Birmingham.
The CART results and meteorological characterization tool were used to explore several questions re lated to modeling episode period representativeness. The characteristics of the 2000-2004 baseline period and each individual year comprising that period are examined for Birmingham using both the STN and SEARCH data in Tables A-4 and A-5. The summary metrics included in this table are the weighted average PM 2.5 

### concentration, range in PM 2.5 

### concentration, percentage of key PM 2.5 

### bins represented (considering all classes), and the relative distribution of days among the key PM 2.5 

### bins for all categories (distribution error). These terms are explained in more detail in the main report.

Table A-4. Summary of PM 2.5 and Meteorological Characteristics for the 2000-2004 Analysis Period: Birmingham STN Site.

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 18.8 0.4 – 71.3 2000 20.1 0.4 – 71.3 100 2.7 2001 18.4 1.0 – 51.5 100 0.8 2002 17.8 4.2 – 47.8 100 1.1 2003 18.0 2.9 – 46.4 90 1.4 2004 18.4 3.6 – 53.3 80 1.6

Table A-5. Summary of PM 2.5 and Meteorological Characteristics for the 2000-2004 Analysis Period: Birmingham SEARCH Site.

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.9 2.8 – 75.2 2000 18.3 3.8 – 66.4 100 2.3 2001 17.2 3.3 – 48.9 100 1.1 2002 17.5 3.9 – 45.3 100 0.9 2003 16.8 2.8 – 45.0 90.9 1.4 2004 18.0 3.2 – 75.2 100 1.4



### The differences in the ranges and the weighted average concentrations between the STN and SEARCH su mmaries are attributable to differences in the measured data. The distribution

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### errors, however, vary similarly among the years fo r the two datasets. This indicates that in both CART analyses, the days are similarly distributed among the key bins. The results for both analyses suggest that 2002 is one of the more representative years for Birmingham.
The characteristics, attributes, and limitations of the combined VISTAS episode periods (1 June – 10 July and 19 November – 19 December, 2002) for PM 2.5 

### for Birmingham are examined and compared in Table A-6 and A-7 for the STN and SEARCH analyses, respectively. The summary metrics are the same as those for Tables A-4 and A-5.

Table A-6. Summary of PM 2.5 and Meteorological Characteristics for 2000-2004, 2002, and the 2002 VISTAS Episodic Analysis Periods: Birmingham STN Site.

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over

All Key PM2.5 Bins (%

)

2000–2004 18.8 0.4 – 71.3 2002 17.8 4.2 – 47.8 100 1.1 Episodes 18.8 7.1 – 41.5 100 3.5

Table A-7. Summary of PM 2.5 and Meteorological Characteristics for 2000-2004, 2002, and the 2002 VISTAS Episodic Analysis Periods: Birmingham SEARCH Site.

Period Weighted Average PM2.5 Conce ntration ( μ gm -3

) Range in PM 2.5 Concentration ( μ gm -3

) Percentage of Key PM2.5 Bins Represented (%

) Distribution Error Over All

Key PM2.5

Bins (%)

2000–2004 17.9 2.8 – 75.2 2002 17.5 3.9 – 45.3 100 0.9 Episodes 18.5 5.5 – 41.2 90.9 3.0



### In both cases, the weighted average concentration for the episode days is 1 μ gm -3 

### higher than the 2002 average value and the episode days include at least one high PM 2.5 

### day but not the peak day for 2002. The distribution errors are similar for the two analyses and the larger errors for the episode periods indicate that the episodes do not sample the various types of days with the frequency that is typical of 2002 and multi-year periods.
Finally, to characterize the overall representativeness of the urban-PM 2.5 

### -based episode periods, Figure A-5 compares the average concentration of the PM species for 2000-2004, 2002, and the combined subset episode periods.

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### A-9 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Appendix: Comparison of Results fo r the STN and SEARCH Birmingham Sites

Figure A-5. Comparison of Species Concentrations ( μ gm -3 ) for Sulfate (SO4), Nitrate (NO3), Organic Carbon (OC), Elemental Carbon (EC) and Ammonium (NH4) for 2000-2004, 2002, and 2002 VISTAS Episode Periods: Birmingham. (a) STNμg m-3



# 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4μg m-3



# 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4

(b) SEARCHμg m-3



# 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4 

# 2000-2004 2002 Episodesμg m-3



# 0 1 2 3 4 5 6 7 8

SO4 NO3 OC EC NH4 

# 2000-2004 2002 Episodes

ICF International 

### A-10 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Appendix: Comparison of Results fo r the STN and SEARCH Birmingham Sites



### For both datasets, the average concentrations for all species for 2002 are similar to those for the full period. Using the STN data (Figure A-5a), the ep isodes have higher organic carbon and slightly higher sulfate, nitrate and elemental carbon concentr ations than both 2002 and the full period. Using the SEARCH data, (Figure A-5b), the episodes have sl ightly higher sulfate co ncentrations than both 2002 and the full baseline period. Note that we used two methods for the calculation of the average species concentrations for the episodes, first we us ed all data and then we recalculated using only data for those days with both ST N and SEARCH data. Results for th e second method are shown in the plots, but the conclusions are the same for both methods. The representativeness of the concentration characteristics of the episode days differs between the two datasets. 

## Summary of Findings
In summary, there are differences in the measured PM 2.5 

### and species concentrations between the STN and SEARCH datasets for Birmingham. Despite the differences in the PM 2.5 

### concentrations, the variation in the average characteristic s of the days within percentage-based PM 2.5 

### classification categories is similar between the two datasets. Consequently, the STN and SEARCH CART analyses for Birmingham are similar with respect to classification accuracy, relative importance of the input parameters, and the overall conditions leading to the high PM 2.5 

### classification bins.
Both CART analyses separate the days with very high prior-day concentrations and northwesterly to northerly winds from the remai ning high PM 2.5 

### days. The analysis using the SEARCH data provides some additional detail and further divides the remaining days into two groups with different physical characteristics. Use of collocated surface meteorological data in the SEARCH analysis may allow CART to better detect the relationships between the PM 2.5 

### values and the meteorological parameters, or the SEARCH PM 2.5 

### measurement techniques may be better in tune with the effects of meteorology.

The concentration characteristics of the key bins for the STN and SEARCH analysis are consistent in that organic matter tends to be the dominant species in both sets of results. The relative species concentrations, however, vary among the key bins and between the two analyses.
For both analyses, the 2002 and subset episode days are similarly distributed among the key bins and t he results for both analyses suggest that 2002 is one of the more meteorologically representative years for Birmingham, considering the period 2000-2004. The representativeness of the concentration characteristics of the episode days differs between the two datasets.

ICF International 

### A-11 VISTAS Meteorological Characterization

06-046 December 8, 2006Characterization of Meteorology and Its Relationships to Fine Particulate Mass and Visibility in the VISTAS Region Appendix: Comparison of Results fo r the STN and SEARCH Birmingham Sites



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ICF International 

### A-12 VISTAS Meteorological Characterization

06-046 December 8, 2006SUMMARY OF METEOROLOGICALCONDITIONS AND CART RESULTSFOR IMPROVE SITES IN NCPrepared bySharon Douglas and Belle HudischewskyjICF InternationalCharacterizing Meteorology• Objectives:– Characterize relationship between meteorology, PM2.5,visibility, for IMPROVE, STN, and SEARCH sites– Evaluate how well meteorological and visibility conditionsof the 2002 modeling year represents the 2000-2004baseline periodClassifying Days using Visibility,Meteorology, and PM2.5• Classification and Regression Tree (CART) analyses– Classify days based onextinction coefficient– 5 extinction classes defined for each site• 20th, 50th, 80th, and 95thpercentiles– 2000-2004 data– 21 IMPROVE, 8 SEARCH, 16 STN sitesClassifying Days Using Visibility,Meteorology, and PM2.5• Classification and Regression Tree (CART) methods– Use meteorological parameters at (or near) the site– Use PM2.5 on previous days at regional/upwind sites– CART decision tree sorts days using most influentialparameters first– Assign days to “bins” of days with similar meteorology– Several bins assigned to same class• different combinations of meteorological conditions can leadto same extinctionCART Results for Visibility atIMPROVE sites• Using only meteorological inputs, 65 to 80% of days areaccurately classified• Adding PM2.5 on previous day at upwind sites improvesaccuracy of classifying days for visibility to 73-88%• Optimal CART decision tree has 25-35 bins• Key parameters vary across sites and classesCART Visibility Analyses –IMPROVE• In general, poor visibility days are associated with– High temperatures– High relative humidity– High PM2.5 on the previous day at upwind sites– Low wind speeds near the surface and aloft– Stable morning conditions– Predominant surface wind direction is site specific• PM2.5 composition on poor visibility days varies by site• Greater variability in conditions leading to good visibilityNOTES ON SUMMARIES OFRESULTS FOR VISIBILITY• Classification accuracy for visibility combines Categories 2& 3, so emphasis is on Category 1 (Best) and 4 & 5(Worst) days• References to high, low etc... are used mostly in a relativeand site specific sense, rather than an absolute sense, tocompare and distinguish the characteristics of the poorvisibility categories (more detailed descriptions areincluded in the project report)CATEGORICAL COMPARISONS FORVISIBILITY FOR GRSM051015202530T (deg C)YFM (μgm-3)<4545-7575-120120-180>=180Surface Characteristics: All Days (2000-2004)/5 Ex. Coeff. Categories (Mm-1)01234WS (m/s)<4545-7575-120120-180>=180090180270360WD (deg)<4545-7575-120120-180>=180020406080100RH (%)<4545-7575-120120-180>=180*Knoxville*CATEGORICAL COMPARISONS FORVISIBILITY: GRSM-1-0.500.51DT (deg C)Persist<4545-7575-120120-180>=180Upper-Air Characteristics: All Days(2000-2004)/5 Ex. Coeff. Categories051015850 mb WS (m/s)<4545-7575-120120-180>=180090180270360850 mb WD (deg)<4545-7575-120120-180>=180*CART PARAMETER IMPORTANCEFOR VISIBILITY: GRSM*CART Variable Importance Averaged Scores - Great SmokyMountains0 20 40 60 80 100CloudsAvg 850 mb w ind directionAvg 850 mb w ind speedYesterday's 700 mb w ind direction (PM)Yesterday's 700 mb w ind speed (PM)700 mb height differenceStabilityAvg 850 mb tempRainSolar radiationPersistenceSurface w ind directionSurface w ind speedRelative humidity at noonAvg surface tempRegional avg of yesterday's max PMCOMPOSITIONAL ANALYSIS FORKEY VISIBILITY BINS: GRSMGreat Smoky Mountains Key Visibility Bins: Component Averages0.002.004.006.008.0010.0012.0014.0016.001 (43) 6 (9) 5 (42) 13 (33) 4 (22) 26 (32) 7 (12) 28 (9) 27 (13) 29 (14) 18 (12) 35 (10) 32 (8) 15 (3)Class 1Class 2Class 3Class 4Class 5Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4SUMMARY OF RESULTS FORVISIBILITY: GRSM• Classification accuracy: 78%• Poor visibility is associated with– Moderate to high prior-day PM2.5 (at upwind sites)– Moderate temperatures and high RH– Low wind speeds near the surface and aloft (esp. Category 5)– WSW winds both aloft and W winds near the surface• PM2.5, temperature, humidity, stability and upper-airwind speed parameters important for CART• Poor visibility regimes are associated with– Moderate to high SO4 and low to moderate OMCOMPOSITIONAL ANALYSIS FORKEY PM2.5 BINS: GRSMGreat Smoky Mountains Key PM Bins: Component Averages0.002.004.006.008.0010.0012.0014.0016.003 (291) 14 (1) 17 (20) 20 (20) 22 (12) 5 (8) 11 (10) 13 (7) 26 (7) 24 (14)Class 1 Class 4 Class 1Class 2Class 3Class 4Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4CATEGORICAL COMPARISONSFOR VISIBILITY FOR LINVILLEGORGE051015202530T (deg C)YFM (μgm-3)<3535-7070-120120-180>=180Surface Characteristics: All Days (2000-2004)/5 Ex. Coeff. Categories (Mm-1)01234WS (m/s)<3535-7070-120120-180>=180090180270360WD (deg)<3535-7070-120120-180>=180020406080100RH (%)<3535-7070-120120-180>=180*Knoxville*CATEGORICAL COMPARISONSFOR VISIBILITY: LINVILLEGORGE-1-0.500.51DT (deg C)Persist<3535-7070-120120-180>=180Upper-Air Characteristics: All Days(2000-2004)/5 Ex. Coeff. Categories051015850 mb WS (m/s)<3535-7070-120120-180>=180090180270360850 mb WD (deg)<3535-7070-120120-180>=180*CART PARAMETERIMPORTANCE FOR VISIBILITY:LINVILLE GORGE*CART Variable Importance Averaged Scores - Linville Gorge0 20 40 60 80 100CloudsRecirculationAvg 850 mb w ind directionAvg 850 mb w ind speedYesterday's 700 mb w ind direction (PM)Yesterday's 700 mb w ind speed (PM)700 mb height differenceStabilityAvg 850 mb tempRainMax surface pressurePersistenceSurface w ind directionSurface w ind speedRelative humidity at noonAvg surface tempRegional avg of yesterday's max PMCOMPOSITIONAL ANALYSISFOR KEY VISIBILITY BINS:LINVILLE GORGELinville Gorge Key Visibility Bins: Component Averages0.002.004.006.008.0010.0012.001 (37) 2 (24) 3 (30) 11 (19) 9 (17) 30 (17) 12 (31) 32 (28) 17 (10) 7 (10) 20 (21) 23 (14) 28 (12)Class 1Class 2Class 3Class 4 Class 5Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4SUMMARY OF RESULTS FORVISIBILITY: LINVILLE GORGE• Classification accuracy: 83%• Poor visibility is associated with– High prior-day PM2.5 (at upwind sites)– High temperatures and relative humidity– Low wind speeds near the surface and aloft– W(NW) winds aloft; NW to N winds near the surface• PM2.5, RH, temperature, stability, and upper-airwind speed parameters important for CART• Poor visibility regimes are associated with– Moderate to high SO4 and low to moderate OMconcentrationsCOMPOSITIONAL ANALYSISFOR KEY PM2.5 BINS: LINVILLEGORGELinville Gorge Key PM Bins: Component Averages0.002.004.006.008.0010.0012.0014.001 (227) 6 (49) 21 (17) 18 (22) 15 (11) 31 (9) 30 (5) 19 (5) 25 (15)Class 1Class 2Class 3Class 4Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4CATEGORICAL COMPARISONSFOR VISIBILITY FOR LINVILLEGORGE051015202530T (deg C)YFM (μgm-3)<3535-7070-120120-180>=180Surface Characteristics: All Days (2000-2004)/5 Ex. Coeff. Categories (Mm-1)01234WS (m/s)<3535-7070-120120-180>=180090180270360WD (deg)<3535-7070-120120-180>=180020406080100RH (%)<3535-7070-120120-180>=180*Knoxville*CATEGORICAL COMPARISONSFOR VISIBILITY: LINVILLEGORGE-1-0.500.51DT (deg C)Persist<3535-7070-120120-180>=180Upper-Air Characteristics: All Days(2000-2004)/5 Ex. Coeff. Categories051015850 mb WS (m/s)<3535-7070-120120-180>=180090180270360850 mb WD (deg)<3535-7070-120120-180>=180*CART PARAMETERIMPORTANCE FOR VISIBILITY:LINVILLE GORGE*CART Variable Importance Averaged Scores - Linville Gorge0 20 40 60 80 100CloudsRecirculationAvg 850 mb w ind directionAvg 850 mb w ind speedYesterday's 700 mb w ind direction (PM)Yesterday's 700 mb w ind speed (PM)700 mb height differenceStabilityAvg 850 mb tempRainMax surface pressurePersistenceSurface w ind directionSurface w ind speedRelative humidity at noonAvg surface tempRegional avg of yesterday's max PMCOMPOSITIONAL ANALYSISFOR KEY VISIBILITY BINS:LINVILLE GORGELinville Gorge Key Visibility Bins: Component Averages0.002.004.006.008.0010.0012.001 (37) 2 (24) 3 (30) 11 (19) 9 (17) 30 (17) 12 (31) 32 (28) 17 (10) 7 (10) 20 (21) 23 (14) 28 (12)Class 1Class 2Class 3Class 4 Class 5Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4SUMMARY OF RESULTS FORVISIBILITY: LINVILLE GORGE• Classification accuracy: 83%• Poor visibility is associated with– High prior-day PM2.5 (at upwind sites)– High temperatures and relative humidity– Low wind speeds near the surface and aloft– W(NW) winds aloft; NW to N winds near the surface• PM2.5, RH, temperature, stability, and upper-airwind speed parameters important for CART• Poor visibility regimes are associated with– Moderate to high SO4 and low to moderate OMconcentrationsCOMPOSITIONAL ANALYSISFOR KEY PM2.5 BINS: LINVILLEGORGELinville Gorge Key PM Bins: Component Averages0.002.004.006.008.0010.0012.0014.001 (227) 6 (49) 21 (17) 18 (22) 15 (11) 31 (9) 30 (5) 19 (5) 25 (15)Class 1Class 2Class 3Class 4Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4CATEGORICAL COMPARISONSFOR VISIBILITY FORSWANQUARTER051015202530T (deg C)YFM (μgm-3)<4040-7070-115115-175>=175Surface Characteristics: All Days (2000-2004)/5 Ex. Coeff. Categories (Mm-1)01234WS (m/s)<4040-7070-115115-175>=175090180270360WD (deg)<4040-7070-115115-175>=175020406080100RH (%)<4040-7070-115115-175>=175*Norfolk*CATEGORICAL COMPARISONSFOR VISIBILITY:SWANQUARTER-1-0.500.51DT (deg C)Persist<4040-7070-115115-175>=175Upper-Air Characteristics: All Days(2000-2004)/5 Ex. Coeff. Categories051015850 mb WS (m/s)<4040-7070-115115-175>=175090180270360850 mb WD (deg)<4040-7070-115115-175>=175*CART PARAMETERIMPORTANCE FOR VISIBILITY:SWANQUARTER*CART Variable Importance Averaged Scores - Swanquarter0 20 40 60 80 100CloudsRecirculationAvg 850 mb w ind directionAvg 850 mb w ind speedYesterday's 700 mb w ind direction (PM)Yesterday's 700 mb w ind speed (PM)700 mb height differenceStabilityAvg 850 mb tempRainMax surface pressurePersistenceSurface w ind directionSurface w ind speedRelative humidity at noonAvg surface tempRegional avg of yesterday's max PMCOMPOSITIONAL ANALYSISFOR KEY VISIBILITY BINS:SWANQUARTERSwanquarter Key Visibility Bins: Component Averages0.002.004.006.008.0010.002 (17) 19 (12) 4 (6) 5 (40) 29 (9) 14 (31) 31 (19) 7 (9) 28 (6) 30 (6) 23 (6) 27 (15)Class 1Class 2Class 3Class 4 Class 5Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4SUMMARY OF RESULTS FORVISIBILITY: SWANQUARTER• Classification accuracy: 80%• Poor visibility is associated with– Moderate prior-day PM2.5 (big jump to Category 5)– Moderate temperatures and high RH– Moderate wind speeds (slight decreasing tendency near sfc)– W winds aloft and SW to W winds near the surface• PM2.5, RH, pressure and other surface and upper-airmet parameters important for CART• Poor visibility regimes are associated with– Moderate SO4 and low to moderate OM concentrationsCOMPOSITIONAL ANALYSISFOR KEY PM2.5 BINS:SWANQUARTERSwanquarter Key PM Bins: Component Averages0.002.004.006.008.0010.0012.005 (160) 24 (29) 16 (11) 12 (9) 21 (13) 17 (5) 13 (6) 28 (4)Class 1Class 2Class 3Class 4Bin No. (No. of Correctly Classified Days)

Avg. Conc. (μg/m3 )ECNO3OMSO4