A-1

APPENDIX A

Nephelometer Comparisons
A-2

All Days

y = 0.97x + 5.02

R2 = 0.86

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 1.26x - 2.

R2 = 0.70

0

50

100150200250300

0 50 100 

Q1

y = 0.67x + 14.69

R2 = 0.79

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.94x + 5

R2 = 0.91

0

50

100150200250300

0 50 100 

Q3

y = 0.95x + 6.02

R2 = 0.80

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

J-04

F-04

M-04

A-04

M-04

J-04

J-04

A-04

S-04

O-04

N-04

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

COHU1, 2004
A-3

All Days

y = 0.77x + 11.09

R2 = 0.91

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 1.12x + 0

R2 = 0.81

0

50

100150200250300

0 50 100 

Q1

y = 0.64x + 14.07

R2 = 0.86

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.75x + 1

R2 = 0.94

0

50

100150200250300

0 50 100 

Q3

y = 0.70x + 18.76

R2 = 0.90

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

J-04

F-04

M-04

A-04

M-04

J-04

J-04

A-04

S-04

O-04

N-04

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

COHU1, 2004
A-4

COHU1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2004

0

50

100150200250300

2/18

2/21

2/24

3/1

3/16

3/19

3/22

3/25

3/28

4/3

4/6

4/9

4/15

4/18

4/21

4/24

4/27

5/3

5/6

5/9

5/15

5/21

5/24

5/27

6/5

6/11

8/4

8/7

8/13

8/16

8/19

8/22

8/31

9/3

9/6

9/12

9/21

9/24

9/27

9/30

10/3

10/6

10/9

10/15

10/18

11/5

11/8

11/14

11/17

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-5

All Days

y = 0.96x + 5.19

R2 = 0.79

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.76x + 

R2 = 0.80

0

50

100150200250300

0 50 100 

Q1

y = 0.92x + 8.10

R2 = 0.75

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.81x + 1

R2 = 0.64

0

50

100150200250300

0 50 100 

Q3

y = 1.08x - 1.18

R2 = 0.85

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1993

1994

1995

1996

1997

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

OKEF1, 1993 - 1997
A-6

All Days

y = 0.71x + 14.59

R2 = 0.81

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.73x + 1

R2 = 0.81

0

50

100150200250300

0 50 100 

Q1

y = 0.83x + 10.29

R2 = 0.79

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.64x + 1

R2 = 0.71

0

50

100150200250300

0 50 100 

Q3

y = 0.70x + 17.84

R2 = 0.84

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1993

1994

1995

1996

1997

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

OKEF1, 1993 - 1997
A-7

OKEF1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

1996

0

20406080

100120140160180

1/6

1/10

1/13

1/20

1/24

1/27

1/31

2/7

2/14

2/17

2/24

3/6

3/9

3/13

3/16

3/20

3/23

4/3

4/10

4/13

4/17

4/20

4/24

4/27

5/4

5/8

5/15

5/18

5/22

5/25

5/29

6/1

6/5

6/12

6/19

6/22

6/26

7/3

7/10

7/20

7/24

7/27

8/24

9/7

9/14

10/5

10/12

10/19

10/30

11/9

11/13

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-8

All Days

y = 0.93x + 5.76

R2 = 0.78

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.95x + 1

R2 = 0.77

0

50

100150200250300

0 50 100 

Q1

y = 0.77x + 9.13

R2 = 0.80

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.88x + 1

R2 = 0.80

0

50

100150200250300

0 50 100 

Q3

y = 0.98x + 15.13

R2 = 0.81

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

MACA1, 1993 - 2004
A-9

All Days

y = 0.75x + 12.54

R2 = 0.82

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.79x + 8

R2 = 0.81

0

50

100150200250300

0 50 100 

Q1

y = 0.72x + 10.95

R2 = 0.83

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.70x + 1

R2 = 0.85

0

50

100150200250300

0 50 100 

Q3

y = 0.71x + 23.00

R2 = 0.83

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

MACA1, 1993 - 2004
A-10

MACA1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2004

0

20406080

100120140160180

1/1

1/4

1/7

1/10

1/16

1/19

1/22

1/28

1/31

2/9

2/12

2/15

2/18

2/21

2/24

2/27

3/4

3/7

3/10

3/13

3/19

3/22

3/25

3/28

3/31

4/3

4/6

4/9

4/15

4/18

4/24

4/27

5/6

5/9

5/12

5/21

5/24

5/27

5/30

6/2

6/5

6/20

6/23

6/26

7/14

7/23

8/7

8/13

8/16

8/19

9/6

9/15

9/18

9/21

9/27

10/3

10/6

10/9

10/15

10/24

10/30

11/5

11/8

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-11

All Days

y = 0.75x + 7.98

R2 = 0.77

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.36x + 1

R2 = 0.47

0

50

100150200250300

0 50 100 

Q1

y = 0.30x + 15.41

R2 = 0.34

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.85x + 1

R2 = 0.91

0

50

100150200250300

0 50 100 

Q3

y = 0.87x + 9.64

R2 = 0.77

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1994

1995

1996

1997

1998

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

SHRO1, 1994 - 1999
A-12

All Days

y = 0.62x + 11.79

R2 = 0.78

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.37x + 1

R2 = 0.51

0

50

100150200250300

0 50 100 

Q1

y = 0.32x + 16.25

R2 = 0.37

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.65x + 1

R2 = 0.88

0

50

100150200250300

0 50 100 

Q3

y = 0.63x + 23.88

R2 = 0.79

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1994

1995

1996

1997

1998

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

SHRO1, 1994 - 1999
A-13

SHRO1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

1997

0

20406080

100120140160180200

1/15

1/18

2/12

2/19

3/5

3/8

3/12

3/15

3/22

3/29

4/2

4/5

4/16

4/26

5/7

5/10

5/14

5/17

5/21

6/11

6/18

9/13

9/20

10/1

10/4

10/15

10/22

10/29

11/5

11/15

11/19

11/22

11/26

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-14

All Days

y = 1.30x - 6.57

R2 = 0.91

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 1.21x - 4

R2 = 0.98

0

50

100150200250300

0 50 100 

Q1

y = 0.77x + 16.08

R2 = 0.30

0

50

100150200250300

0 50 100 150 200 250 300

y = 1.26x - 6.

R2 = 0.94

0

50

100150200250300

0 50 100 

Q3

y = 1.42x - 14.47

R2 = 0.95

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

J-04

F-04

M-04

A-04

M-04

J-04

J-04

A-04

S-04

O-04

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

ROMA1, 2004
A-15

All Days

y = 1.00x + 3.56

R2 = 0.94

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 1.14x - 1

R2 = 0.98

0

50

100150200250300

0 50 100 

Q1

y = 0.79x + 12.27

R2 = 0.57

0

50

100150200250300

0 50 100 150 200 250 300

y = 1.06x + 1

R2 = 0.95

0

50

100150200250300

0 50 100 

Q3

y = 1.00x + 1.96

R2 = 0.97

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

J-04

F-04

M-04

A-04

M-04

J-04

J-04

A-04

S-04

O-04

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

ROMA1, 2004
A-16

ROMA1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2004

0

20406080

100120140160180

1/16

1/19

1/28

1/31

2/9

2/18

2/21

3/1

3/7

3/10

3/13

3/19

3/22

3/28

3/31

4/3

4/15

4/18

4/21

4/24

5/12

5/15

5/18

5/24

5/27

5/30

6/14

6/17

6/20

6/23

6/26

6/29

7/8

7/14

7/17

7/26

8/1

8/4

8/7

8/10

9/3

9/12

9/18

9/21

9/24

10/6

10/15

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-17

All Days

y = 0.98x + 5.97

R2 = 0.87

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 1.04x - 0

R2 = 0.94

0

50

100150200250300

0 50 100 

Q1

y = 0.69x + 12.95

R2 = 0.46

0

50

100150200250300

0 50 100 150 200 250 300

y = 1.03x + 7

R2 = 0.89

0

50

100150200250300

0 50 100 

Q3

y = 0.87x + 19.40

R2 = 0.76

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

2000

2001

2002

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

GRSM1, 2000 - 2004
A-18

All Days

y = 0.71x + 14.70

R2 = 0.89

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.71x + 1

R2 = 0.92

0

50

100150200250300

0 50 100 

Q1

y = 0.63x + 13.92

R2 = 0.62

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.7

R2 

0

50

100150200250300

0 50 100 

Q3

y = 0.62x + 26.41

R2 = 0.82

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

2000

2001

2002

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

GRSM1, 2000 - 2004
A-19

GRSM1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2004

0

50

100150200250

1/1

1/4

1/7

1/13

1/16

1/19

1/22

1/28

1/31

2/9

2/21

2/24

3/1

3/4

3/7

3/10

3/13

3/19

3/22

3/25

3/28

4/3

4/6

4/9

4/15

4/18

4/21

4/24

4/27

4/30

5/9

5/12

5/15

5/21

5/24

5/27

5/30

6/2

6/5

6/11

6/14

6/17

6/20

6/29

7/5

7/8

7/11

7/23

7/29

8/1

8/4

8/7

8/10

8/16

8/19

8/25

8/28

9/3

9/6

9/12

9/15

9/18

9/21

9/24

9/27

10/6

10/9

10/15

10/18

10/27

10/30

11/2

11/5

11/8

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-20

All Days

y = 1.05x + 6.69

R2 = 0.86

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.87x + 1

R2 = 0.78

0

50

100150200250300

0 50 100 

Q1

y = 1.16x + 0.71

R2 = 0.90

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.99x + 

R2 = 0.8

0

50

100150200250300

0 50 100 

Q3

y = 1.12x + 8.54

R2 = 0.82

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

2000

2001

2002

2003

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

JARI1, 2000-2003
A-21

All Days

y = 0.79x + 12.96

R2 = 0.86

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.73x + 1

R2 = 0.83

0

50

100150200250300

0 50 100 

Q1

y = 1.02x + 3.63

R2 = 0.90

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.73x + 1

R2 = 0.86

0

50

100150200250300

0 50 100 

Q3

y = 0.74x + 20.16

R2 = 0.83

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

2000

2001

2002

2003

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

JARI1, 2000-2003
A-22

JARI1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2002

0

50

100150200250

1/2

1/5

1/8

1/11

1/14

1/17

1/26

1/29

2/1

2/4

2/13

2/16

2/19

2/22

2/25

2/28

3/6

3/9

3/15

3/21

3/24

3/30

4/2

4/5

4/8

4/11

4/14

4/17

4/20

4/23

4/26

4/29

5/5

5/11

5/14

5/17

5/20

5/23

5/26

6/1

6/4

6/7

6/13

6/16

6/22

6/25

7/1

7/4

7/7

7/13

7/16

7/22

7/31

8/3

8/6

8/9

8/12

8/15

8/21

8/24

8/27

8/30

9/2

9/5

9/8

9/11

9/23

10/5

10/8

10/14

10/20

11/1

11/7

11/10

11/13

11/22

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep
A-23

All Days

y = 1.03x + 3.53

R2 = 0.80

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.80x + 6

R2 = 0.69

0

50

100150200250300

0 50 100 

Q1

y = 0.91x + 6.23

R2 = 0.50

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.95x + 8

R2 = 0.80

0

50

100150200250300

0 50 100 

Q3

y = 1.04x + 14.11

R2 = 0.82

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1996

1997

1998

1999

2000

2001

2002

2003

2004

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using New IMPROVE Algorithm (nia) and Daily f(RH)

SHEN1, 1996 - 2004
A-24

All Days

y = 0.79x + 11.12

R2 = 0.81

0

50

100150200250300

0 50 100 150 200 250 300

24-hr Nephelometer bsp (Mm-1)

24-hr Aerosol bsp (Mm-1)

y = 0.70x + 9

R2 = 0.71

0

50

100150200250300

0 50 100 

Q1

y = 0.90x + 6.87

R2 = 0.70

0

50

100150200250300

0 50 100 150 200 250 300

y = 0.73x + 1

R2 = 0.79

0

50

100150200250300

0 50 100 

Q3

y = 0.72x + 25.20

R2 = 0.82

0

50

100150200250300

0 50 100 150 200 250 300

-100

-75-50-25

0

255075

100

1996

1997

1998

1999

2000

2001

2002

2003

2004

Difference (Mm-1) 

(Aer. bsp - Neph. bsp

)

Aerosol Scattering vs. Nephelometer Scattering

Using Old IMPROVE Algorithm (oia) and Daily f(RH)

SHEN1, 1996 - 2004
A-25

SHEN1 Daily Extinction

New IMPROVE Algorithm (left bar) Old IMPROVE Algorithm (right bar) and Neph (grey 

Extinction by Species

2004

0

50

100150200250300

1/1

1/4

1/7

1/13

1/16

1/19

1/22

1/25

1/28

1/31

2/15

2/18

2/21

2/27

3/1

3/4

3/7

3/10

3/13

3/19

3/22

3/25

4/6

4/15

4/18

4/30

5/3

5/6

5/9

5/12

5/24

6/2

6/17

6/20

6/26

6/29

7/5

7/8

7/17

8/4

8/7

8/31

10/6

10/9

10/12

10/18

11/5

11/8

11/11

11/14

11/17

11/26

11/29

Extinction (Mm-1)

Amm SO4 Amm NO3 POM Soil CM Sea Salt nep