# IMPROVE

Interagency Monitoring of Protected Visual Environments



# CIRA

Cooperative Institute for Research in the Atmosphere 

# CIRA

Cooperative Institute for Research in the Atmosphere 

# IMPROVE

Spatial and Seasonal Patterns and Temporal Variability of Haze and its Constituents in the United States S p a t i a l a n d S e a s o n a l P a t t e r n s
a n d T e m p o r a l V a r i a b i l i t y o f H a z e
a n d i t s C o n s t i t u e n t s i n t h e U n i t e d S t a t e s

ISSN 0737-5352-87 ISSN 0737-5352-87 

# eport V R e p o r t V

June 2011 June 2011

Acadia NP

1990 1995 2000 2005 2010 Year 0 2 4 6 8(μg/m )3 

### 50 th 

### PercentilePM2.5In celebration of the IMPROVE network’s 25 th anniversary, we dedicate this report to all

of the hard working operators, technicians

, and scientists who have contributed to the

success of the IMPROVE network over the years.

Description of the cover: The front cover displays a split screen of two images from Acadia National Park that represent visibility levels corresponding to the 50 th percentile

, PM 2.5 fine mass aerosol concentrations in 1989 (left) compared to those in 2008 ( right )

. A not iceable improvement in visibility levels occurred due to the decrease in aerosol concentrations over the 20

- year span. We used the WinHaze 2.9.9 computer software program (Air Resource Specialists, 2011), a power ful tool for visualizing the impact of aeros ol trends on visibility conditions.IMPROVE REPORT V



### Spatial and Seasonal Patterns and Temporal Variability of Haze

and its Constituents in the United States

Report V

ISSN 0737

- 5352

- 87

Principal Author: Jenny L. Hand 1

1 Cooperative Institute for Research in the Atmosphere

Colorado State University Fort Collins, CO 80523

- 1375

Contributors: Scott A. Copeland 1 Derek E. Day 1 Ann M. Dillner 2 Hege Indresand 2 William C. Malm 1 Chuck E. McDade 2 Charles T

. (Tom) Moore, Jr. 3 Marc L. Pitchford 4 Bret A. Schichtel 5 John G. Watson 6

2 Crocker Nuclear Laboratory University of California Davis, CA 95616

- 8569

3 Western Governors’ Association

– Western Regional Air Partnership CSU/CIRA Fort Collins, CO 80523

- 1375

4 National Oceanic and Atmospheric Administration

Desert Research Institute Las Vegas, NV 89119

- 7363

5 National Park Service CSU/CIRA Fort Collins, CO 80523

- 1375

6 Desert Research Institute Reno, NV 89512

Disclaimer The assumptions, findings, conclusions, judgments, and views presented herein are those of the authors and should not be interpreted as necessarily representing the National Park Service or National Oceanic and Atmospheric Administration policies.i IMPROVE REPORT V TABLE OF CONTENTS

O verview and S ummary

................................ ................................ ................................ .............. S

- 1

S.1 Introduction

................................ ................................ ................................ ............ S

- 1

S.2 Aerosol Data

................................ ................................ ................................ .......... S

- 2 S.3 Spatial Patterns i n Rural a nd Urban Speciated Aerosol Concentrations: Implications f

or Urban Excess

................................ ................................ .................... S

- 7

S.3.1 Ammonium Sulfate

................................ ................................ ......................... S

- 8

S.3.2 Ammonium Nitrate

................................ ................................ ......................... S

- 9 S.3.3 Particulate Organic Matter

................................ ................................ ............ S

- 10 S.3.4 Light Absorbing Carbon

................................ ................................ ............... S

- 11

S.4 Seasonal Distributions in Aerosol Mass Concentrations

................................ ..... S

- 12

S.4.1 Ammonium Sulfate

................................ ................................ ....................... S

- 13

S.4.2 Ammonium Nitrate

................................ ................................ ....................... S

- 13

S.4.3 Particulate Organic Matter

................................ ................................ ............ S

- 14 S.4.4 Light Absorbing Carbon

................................ ................................ ............... S

- 15

S.4.5 PM 2.5 Soil Mass

................................ ................................ ............................. S

- 15

S.4.6 PM 2.5 Gravimetric Fine Mass

................................ ................................ ........ S

- 16

S.4.7 Discussion

................................ ................................ ................................ ..... S

- 17 S.5 Spatial and Seasonal Patterns in Relative Reconstructed Aerosol Light Extinction Coefficients

................................ ................................ ................................ ............... S

- 18

S.5.1 Deciview

................................ ................................ ................................ ....... S

- 19 S.5.2 Ammonium Sulfate Light Extinction Coefficients

................................ ....... S

- 21 S.5.3 Ammonium Nitrate Light Extinction Coefficients

................................ ....... S

- 24 S.5.4 Particulate Organic Matter Light Extinction Coefficients

............................ S

- 24 S.5.5 Light Absorbing Carbon Light Extinction Coefficients

............................... S

- 24

S.5.6 PM 2.5 Soil Mass Light Extinction Coefficients

................................ ............ S

- 25 S.6 Trends in IMPROVE Speciated Aerosol Mass Concentrations

.......................... S

- 25

S.6.1 Sulfate Ion Trends

................................ ................................ ......................... S

- 26

S.6.2 Nitrate Ion Trends

................................ ................................ ......................... S

- 27

S.6.3 Total Carbon Trends

................................ ................................ ..................... S

- 29

S.6.4 Gravimetric PM 2.5 Fine Mass Trends

................................ ............................ S

- 30 S.7 Regional Haze Rule Metrics

................................ ................................ ............... S

- 32

References

................................ ................................ ................................ .................. S

- 33ii IMPROVE REPORT V Chapter 1. Interagency Monitoring of Protected Visual Environments (IMPROVE) Network: Configuration and Measurements

................................ ................................ ................................ 1

- 1

1.1 Introduction

................................ ................................ ................................ ............ 1

- 1 1.2 Overview of the Improve Monitoring Network

................................ ..................... 1

- 3

1.2.1 Site Location

................................ ................................ ................................ ... 1

- 3 1.2.2 Aerosol Sampling and Analysis

................................ ................................ .... 1

- 14 1.2.3 Optical Sampling and Analysis

................................ ................................ ..... 1

- 19 1.3 Protocol and Equipment Changes

................................ ................................ ........ 1

- 25 1.3.1 Analytical Changes

................................ ................................ ....................... 1

- 25

1.3.1.1 Introduction of a New Model Carbon Analyzer

................................ .... 1

- 25

1.3.1.2 Transition from He Flush to Vacuum Chamber Cu

- Anode XRF

.......... 1

- 26

1.3.1.3 Introduction of New Calibration Foils for Mo

- Anode XRF

.................. 1

- 26 1.3.1.4 Processing XRF Calibration Data

................................ .......................... 1

- 27 1.3.1.5 New XRF Quality Assurance Reports & Clarification of Data Acceptance Criteria

................................ ................................ ................................ ............... 1

- 28 1.3.2 Sampling Equipment Changes

................................ ................................ ...... 1

- 28

1.3.2.1 Filter Masks Removed

................................ ................................ ........... 1

- 28 1.3.2.2 Quartz Backup Filters Added at Six Sites

................................ .............. 1

- 29 1.3.2.3 New Cassette Design for the IMPROVE Sampler

................................ 1

- 29 1.3.3 Data Processing Changes

................................ ................................ .............. 1

- 33 1.3.3.1 Change in the Definition of Flow Rate Native Flags

............................. 1

- 33 1.3.4 Changes or Interferences Noted Through Data Analysis

............................. 1

- 34

1.3.4.1 Sulfur Interference in the Determination of Silicon

.............................. 1

- 34

1.3.4.2 Shifts in the S/SO 4 = Ratio

................................ ................................ ..... 1

- 34

1.4. Chem ical Speciation Network

................................ ................................ ............ 1

- 35

R eferences

................................ ................................ ................................ .................. 1

- 45 Chapter 2. Spatial Patterns of Speciated PM 2.5 Aerosol Mass Concentrations

....................... 2

- 1 2.1 Aerosol Species Composition

................................ ................................ ................ 2

- 3

2.1.1 PM 2.5 Ammonium Sulfate Mass Concentrations

................................ ............ 2

- 4

2.1.2 PM 2.5 Ammonium Nitrate Mass Concentrations

................................ ............ 2

- 4

2.1.3 PM 2.5 Particulate Organic Matter and Light Absorbing Carbon Mass Concentrations

................................ ................................ ................................ ..................... 2

- 4

2.1.4 PM 2.5 Soil Mass Concentration

................................ ................................ ....... 2

- 7iii IMPROVE REPORT V 2.1.5 PM 2.5 Sea Salt Mass Conce ntration

................................ ................................ 2

- 8

2.1.6 PM 2.5 Gravimetric Fine Mass and Reconstructed Fine Mass

......................... 2

- 8

2.1.7 PM 2.5 Mass Difference

................................ ................................ .................... 2

- 8

2.1.8 PM 10 and Coarse Mass Concentrations

................................ ........................... 2

- 9 2.2 Spatial Patterns in Annual Mean Mass Concentrations

................................ ......... 2

- 9

2.2.1 PM 2.5 Ammonium Sulfate Mass

................................ ................................ ..... 2

- 9

2.2.2 PM 2.5 Ammonium Nitrate Mass

................................ ................................ .... 2

- 12

2.2.3 PM 2.5 Particulate Organic Matter Mass

................................ ........................ 2

- 15

2.2.4 PM 2.5 Light Absorbing Carbon Mass

................................ ............................ 2

- 18

2.2.5 PM 2.5 Soil Mass

................................ ................................ ............................. 2

- 21

2.2.6 PM 2.5 Sea Salt Mass

................................ ................................ ...................... 2

- 24

2.2.7 PM 2.5 Gravimetric Fine Mass

................................ ................................ ........ 2

- 26

2.2.8 PM 2.5 Reconstructed Fine Mass

................................ ................................ .... 2

- 28

2.2.9 Differences in PM 2.5 Gravimetric and Reconstructed Fine Mass

................. 2

- 29

2.2.10 Coarse Mass

................................ ................................ ................................ 2

- 31

2.2.10 PM 10 Mass

................................ ................................ ................................ ... 2

- 32

References

................................ ................................ ................................ .................. 2

- 33 Chapter 3. Reconstructed Aerosol Ligh t Extinction Coefficients

................................ ............... 3

- 1 3.1 IMPROVE Aerosol Light Extinction Coefficient Algorithm

................................ 3

- 1

3.2 PM 2.5 Ammonium Sulfate Light Extinction Coefficients

................................ ...... 3

- 5

3.3 PM 2.5 Ammonium Nitrate Light Extinction Coefficients

................................ ...... 3

- 7

3.4 PM 2.5 Particulate Organic Matter Light Extinction Coefficients

......................... 3

- 10

3.5 PM 2.5 Light Absorbing Carbon Light Extinction Coefficients

............................ 3

- 13

3.6 PM 2.5 Fine Soil Light Extinction Coefficients

................................ ..................... 3

- 16

3.7 PM 2.5 Sea salt Extinction Coefficients

................................ ................................ . 3

- 18

3.8 PM 2.5 Reconstructe d Aerosol Light Extinction Coefficients

............................... 3

- 21 3.9 Coarse Mass Light Extinction Coefficients

................................ ......................... 3

- 22

3.10 PM 2.5 Deciview

................................ ................................ ................................ .. 3

- 24

References

................................ ................................ ................................ .................. 3

- 25 Chapter 4. Seasonal Distributions of PM 2.5 Aerosol Mass Concentrations

................................ . 4

- 1

4.1 PM 2.5 Ammonium Sulfate Mass Concentra tions

................................ ................... 4

- 2

4.2 PM 2.5 Ammonium Nitrate Mass Concentrations

................................ ................. 4

- 22

4.3 PM 2.5 Particulate Organic Matter Mass Concentrations

................................ ...... 4

- 26iv IMPROVE REPORT V 4.4 PM 2.5 Light Absorbing Carbon Mass Concentrations

................................ ......... 4

- 30

4.5 PM 2.5 Soil Mass Concentrations

................................ ................................ .......... 4

- 34

4.6 PM 2.5 Sea Salt Mass Concentrations

................................ ................................ .... 4

- 38

4.7 PM 2.5 Gravimetric Fine Mass Concentrations

................................ ..................... 4

- 42

4.8 Coarse Mass Concentrations

................................ ................................ ................ 4

- 44

4.9 Discussion

................................ ................................ ................................ ............ 4

- 49

R eferences

................................ ................................ ................................ .................. 4

- 51 Chapter 5. Seasonal Distribution of PM 2.5 Reconstructed Aerosol Light Extinction Coefficients

................................ ................................ ................................ ................................ .. 5

- 1

5.1 PM 2.5 Ammonium Sulfate Light Extinction Coefficients

................................ ...... 5

- 1

5.2 PM 2.5 Ammonium Nitrate Light Extinction Coefficients

................................ .... 5

- 21

5.3 PM 2.5 Particulate Organic Matter Light Extinction Coefficients

......................... 5

- 27

5.4 PM 2.5 Light Absorbing Carbon Light Extinction Coefficien t

.............................. 5

- 32

5.5 PM 2.5 Soil Light Extinction Coefficients

................................ ............................. 5

- 36

5.6 PM 2.5 Sea Salt Light Extinction Coefficients

................................ ....................... 5

- 42

5.7 PM 2.5 Reconstructed Aerosol Light Extinction Coefficients

............................... 5

- 46 5.8 Coarse Mass Light Extinction Coefficients

................................ ......................... 5

- 48

5.9 PM 2.5 Deciview

................................ ................................ ................................ .... 5

- 52 5.10 Summary

................................ ................................ ................................ ............ 5

- 53

R eferences

................................ ................................ ................................ .................. 5

- 53 Chapter 6. Trends in IMPROVE Speciated Aerosol Concentrations

................................ ...... 6

- 1

6.1 Sulfate Ion Trends

................................ ................................ ................................ .. 6

- 3

6.2 Nitrate Ion Trends

................................ ................................ ................................ 6

- 14

6.3 Total Carbon Trends

................................ ................................ ............................ 6

- 18

6.4 PM 2.5 Soil Trends

................................ ................................ ................................ . 6

- 26

6.5 Gravimetric PM 2.5 Fine Mass Trends

................................ ................................ .. 6

- 36

6.6 Coarse Mass Trends

................................ ................................ ............................. 6

- 44

6.7 PM 10 Gravimetric Mass Trends

................................ ................................ ........... 6

- 53

References

................................ ................................ ................................ .................. 6

- 60 Chapter 7. Urban Excess in PM 2.5 Speciated Aerosol Concentrations

................................ ........ 7

- 1

7.1 Introduction and Method

................................ ................................ ........................ 7

- 1

7.2. Ammonium Sulfate

................................ ................................ ............................... 7

- 4

7.3 Ammonium Nitrate

................................ ................................ ................................ 7

- 7v IMPROVE REPORT V 7.4 Particulate Organic Matter

................................ ................................ ................... 7

- 10 7.5 Light Absorbing Carbon

................................ ................................ ...................... 7

- 14

7.6 PM 2.5 Gravimetric Fine Mass

................................ ................................ ............... 7

- 17 7.7 Summary

................................ ................................ ................................ .............. 7

- 20

References

................................ ................................ ................................ .................. 7

- 22 Chapter 8. Uncertainties in PM 2.5 Gravimetric and Speciation Measurements

........................... 8

- 1

Abstract

................................ ................................ ................................ ........................ 8

- 1 Implications

................................ ................................ ................................ .................. 8

- 1

8.1 Introduction

................................ ................................ ................................ ............ 8

- 2 8.2 Sample Collection Systems

................................ ................................ .................... 8

- 3 8.2.1 Interagency Monitoring of Protected Visual Environments (IMPROVE)

..... 8

- 4 8.2.2 The Chemical Speciation Network (CSN)

................................ ...................... 8

- 5 8.2.3 Exploration of the Differences in the IMPROVE and CSN Carbon Measurements

................................ ................................ ................................ ...................... 8

- 5 8.2.4 Relating CSN to IMPROVE Carbon Concentrations

................................ ..... 8

- 9

8.2.4.1 Converting CSN to IMPROVE Carbon Concentrations.

....................... 8

- 10 8.2.5 Comparison of Reconstructed to Measured Mass

................................ ........ 8

- 13 8.3 Investigating Bias Associated with each Species

................................ ................ 8

- 20

8.3.1 Bias in Gravimetric Mass

................................ ................................ .............. 8

- 28

8.3.2 Bias in Reconstructed Mass

................................ ................................ .......... 8

- 29 8.4 Spatial and S easonal V ariability in PM 2.5 and RPM 2.5 B ias es

............................. 8

- 29 8.5 Summary

................................ ................................ ................................ .............. 8

- 33

References

................................ ................................ ................................ .................. 8

- 35 Chapter 9. Regional Haze Rule Progress Tracking Metrics

................................ .................... 9

- 1

9.1 Introduction

................................ ................................ ................................ ............ 9

- 1 9.2 Regional Haze Rule Assessment

................................ ................................ ........... 9

- 2 9.2.1 Uniform Rate of Progress

................................ ................................ ............... 9

- 2 9.2.2 Regional Haze Rule Metric

................................ ................................ ............. 9

- 4

9.3 Assessment of C hange in Regional Haze from the Baseline (2000

– 2004) to Period 1 (2005

– 2009)

................................ ................................ ................................ .. 9

- 6 9.4 Case Studies of Regional Haze Rule Progress

................................ ..................... 9

- 14 9.4.1 Boundary Waters Canoe Area Wilderness, Minnesota

................................ . 9

- 14 9.4.2 Great Smoky Mountains National Park, Tennessee/North Carolina

............ 9

- 17vi IMPROVE REPORT V 9.4.3 Mesa Verde National Park, Colorado

................................ ........................... 9

- 20 9.4.4 Hell’s Canyon Wilderness, Oregon/Idaho

................................ .................... 9

- 25 9.4.5 Agua Tibia Wilderness, California

................................ ............................... 9

- 30

Reference s

................................ ................................ ................................ .................. 9

- 35 Chapter 10. X

- Ray Fluorescence Reference Materials from an Aerosol Generation System

..........

................................ ................................ ................................ ................................ ................... 10

- 1

10.1 Introduction

................................ ................................ ................................ ........ 10

- 1 10.2 Aerosol Generation System

................................ ................................ ............... 10

- 1 10.3 Testing and Verification

................................ ................................ .................... 10

- 3 Chapter 11. Ammonia and Ammonium Measurements from Passive, Modified IMPROVE and CASTNET Samplers.

................................ ................................ ................................ ................. 11

- 1

11.1 Introduction

................................ ................................ ................................ ........ 11

- 1

11.2 Instrumentation

................................ ................................ ................................ .. 11

- 2

11.2.1 URG Sa mpler

................................ ................................ .............................. 11

- 3 11.2.2 IMPROVE Sampler

................................ ................................ .................... 11

- 3 11.2.3 CASTNET Sampler

................................ ................................ .................... 11

- 4 11.2.4 Passive Samplers

................................ ................................ ......................... 11

- 5 11.3 Comparisons of Data from CASTNET, URG, and IMPROVE Samplers

......... 11

- 6

11.3.1 IMPROVE versus URG

................................ ................................ .............. 11

- 6

11.3.2 CASTNET versus URG

................................ ................................ ............ 11

- 12 11.3.3 Ammonia Comparisons from CASTNET, Passive, and URG Samplers

.. 11

- 20 11.4 Summary

................................ ................................ ................................ .......... 11

- 20

References

................................ ................................ ................................ ................ 11

- 21 Chapter 12. IMPROVE Measurements Bibliography

................................ ............................... 12

- 1

Appendices available at http://vista.cira.colostate.edu/improve/Publications/improve_reports.htm or on cd by request. Appendix A: Comparisons of IMPROVE and CSN 2005

– 2008 Daily Speciated Aerosol Concentrations at Collocated Sites Appendix B: 2005

– 2008 Annual Mean Mass Concentrations and P M 2.5 Mass Fractions for Each Site Appendix C: 2005

– 2008 Annual Mean Reconstructed Light Extinction C oefficients ( b ext ) and P M 2.5 b ext Fractions for Each Site Appendix D: 2005

– 2008 Regional Monthly Mean Mass C oncentrations and P M 2.5 Mass Fractionsvii IMPROVE REPORT V Appendix E: 2005

– 2008 Regional Monthly Mean Mass Concentrations and P M 2.5 Mass Fractions Appendix F1: IMPROVE 20

- Yr Normalized Trends (1989

– 2008) Appendix F2: IMP ROVE 9

- Yr Normalized Trends (2000

– 2008) Appendix G: Supplemental Analysis for Chapter 9 G.1. Regional Haze Rule IMPROVE Progress Tracking Site Data Results by State

G.2. Spatial Maps o f Regional Haze Rule Metricsviii IMPROVE REPORT V LIST OF FIGURES Figure S.2.1. Locations of IMPROVE and IMPROVE protocol sites for all discontinued and current sites. The IMPROVE regions used for grouping the sites are indicated by shading and bold text. Urban sites included in the IMPROVE network for quality assurance purposes are identified by stars.

................................ ................................ ................................ ........................ S

- 4 Figure S.2.2. Current and discontinued Chemical Speciation Network (CSN) sites (grey and orange) operated by the Environmental Protection Agency. Regions are shown as shaded areas and bold text. The sites included in the analyses in this report are shown as orange circles.

...... S

- 5 Figure S.3.1

. (a) IMPROVE and CSN PM 2.5 ammonium sulfate (AS) 2005

– 2008 annual mean mass concentrations (μg m - 3 ). (b) Interpolated ratios of u rban (CSN) to rural (IMPROVE) annual mean AS concentrations for 2005

– 2008. IMPROVE sites are shown as circles; CSN sites used in the analysis are shown as squares. CSN sites with no IMPROVE site within 150 km are shown as triangles. These sites were not us ed in the analysis.

................................ ................................ .... S

- 9 Figure S.3.2

. (a) IMPROVE and CSN PM 2.5 ammonium nitrate (AN) 2005

– 2008 annual mean mass concentrations (μg m - 3 ). (b) Interpolated ratios of urban (CSN) to rural (IMPROVE) annual mean AN concentrations for 2005

– 2008. IMPROVE sites a re shown as circles; CSN sites used in the analysis are shown as squares. CSN sites with no IMPROVE site within 150 km are shown as triangles. These sites were not used in the analysis.

................................ .............................. S

- 10 Figure S.3.3

. (a) IMPROVE and CSN PM 2.5 particulate organic matte r (POM) 2005

– 2008 annual mean mass concentrations (μg m - 3 ). (b) Interpolated ratios of urban (CSN) to rural (IMPROVE) annual mean POM concentrations for 2005

– 2008. IMPROVE sites are shown as circles; CSN sites used in the analysis are shown as squares. CSN sites with no IMPROVE site within 150 km are shown as triangles. These sites were not used in the analysis.

.................... S

- 10 Figure S.3.4

. (a) IMPROVE and CSN PM 2.5 light absorbing carbon (LAC) 2005

– 2008 annual mean mass concentrations (μg m - 3 ). (b) Interpolated rati os of urban (CSN) to rural (IMPROVE) annual mean LAC concentrations for 2005

– 2008. IMPROVE sites are shown as circles; CSN sites used in the analysis are shown as squares. CSN sites with no IMPROVE site within 150 km are shown as triangles. These sites wer e not used in the analysis.

................................ ............ S

- 11 Figure S.4.1

. (a) Seasonal variability for 2005

– 2008 monthly mean IMPROVE ammonium sulfate (AS) mass concentrations. (b) The same as (a), but for the CSN. The color of the upward

pointing triangle refers to the season with the maximum monthly mean concentration, and the downward

- pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentratio n.

................................ ................................ ................................ .......... S

- 13 Figure S.4.2

. (a) Seasonal variability for 2005

– 2008 monthly mean IMPROVE ammonium nitrate (AN) mass concentrations. (b) The same as (a), but for the CSN. The color of the upward

- pointing triangle refers to the season with the maximum monthly mean concentration, and the downward

- pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ........... S

- 14 Figure S.4.3

. (a ) Seasonal variability for 2005

– 2008 monthly mean IMPROVE particulate organic matter (POM) mass concentrations. (b) The same as (a), but for the CSN. The color of the upward

- pointing triangle refers to the season with the maximum monthly meanix IMPROVE REPORT V concentratio n, and the downward

- pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ...................... S

- 14 Figure S.4.4

. (a) Seasonal va riability for 2005

– 2008 monthly mean IMPROVE light absorbing carbon (LAC) mass concentrations. (b) The same as (a), but for the CSN. The color of the upward

- pointing triangle refers to the season with the maximum monthly mean concentration, and the downwa rd

- pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ...................... S

- 15 Figure S.4.5

. (a) Seasonal variability for 200 5

– 2008 monthly mean IMPROVE fine soil mass concentrations. (b) The same as (a), but for the CSN. The color of the upward

- pointing triangle refers to the season with the maximum monthly mean concentration, and the downward

- pointing triangle refers to the s eason with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. S

- 16 Figure S.4.6

. (a) Seasonal variability for 2005

– 2008 monthly mean IMPROVE PM 2.5 gravimetric fine mass (FM) concentrations. (b) The same as (a), but for the CSN. The color of the upward

- pointing triangle refers to the season with the maximum monthly mean concentration, and the downward

- pointing triangle refers to the season with the m inimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ...................... S

- 17 Figure S.5.1a. Annual mean PM 2.5 deciview (dv) for 2005

– 2008 for rural IMPROVE sites. Wavelength c orresponds to 550 nm.

................................ ................................ .......................... S

- 20 Figure S.5.1b. Seasonal variability for 2005

– 2008 monthly mean IMPROVE deciview (dv) light extinction coefficient (b ext ). The color of the upward

- pointing triangle refers to the season with the maximum monthly mean concentration, and the downward

- pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. S

- 20 Figure S.5.2.1. IMPROVE regiona l monthly mean (2005

– 2008) PM 2.5 light extinction coefficient (b ext ) fractions for Hawaii, Alaska, and the Virgin Islands. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) is in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites, shown as dots.

................................ ........... S

- 21 Figure S.5.2.2. IMPROVE regi onal monthly mean (2005

– 2008) PM 2.5 light extinction coefficient (b ext ) fractions for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) is in yellow, ammonium nitrate (A N) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites, shown as dots.

................................ ................................ .......... S

- 22 Figure S.5.2.3. IMPROVE regional month ly mean (2005

– 2008) PM 2.5 light extinction coefficient (b ext ) fractions for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) is inx IMPROVE REPORT V yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites, shown as dots.

................................ ........... S

- 23 Figure S.5.2.4. IMPROVE regional monthly me an (2005

– 2008) PM 2.5 light extinction coefficient (b ext ) fractions for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) is in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites, shown as dots.

................................ ........... S

- 23 Figure S.6.1.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter sulfate ion mass concentrations. Sites with statistically significant trends (p≤0.05) are designated by filled red (increasing) and blue (decreasing) triangles. Insignificant trends (p>0.15) are designated by filled black triangles.

................................ ................................ ................................ ........................... S

- 26 Figure S.6.1.2. Short

- term (2000

– 2008) trends (% yr - 1 ) in average spring sulfate ion mass concentrations. Sites with statistically significant trends (p≤0.05) are designated by filled red (increasing) and blue (decreasing) triangles. Insignificant tr ends (p>0.15) are designated by filled black triangles.

................................ ................................ ................................ ........................... S

- 27 Figure S.6.2.1. Short

- term (2000

– 2008) trends (% yr - 1 ) in 10 th percentile nitrate ion mass concentrations. Sites with statistically significant trends (p≤0.05) are designated by filled red (incre asing) and blue (decreasing) triangles. Insignificant trends (p>0.15) are designated by filled black triangles.

................................ ................................ ................................ ........................... S

- 28 Figure S.6.2.2. Short

- term (2000

– 2008) trends (% yr - 1 ) in 50 th percentile nitrate ion mass concentrations. Sites with statistically signifi cant trends (p≤0.05) are designated by filled red (increasing) and blue (decreasing) triangles. Insignificant trends (p>0.15) are designated by filled black triangles.

................................ ................................ ................................ ........................... S

- 29 Figure S.6.3.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile total carb on (TC = organic carbon + light absorbing carbon) mass concentrations. Sites with statistically significant trends (p≤0.05) are designated by filled red (increasing) and blue (decreasing) triangles. Insignificant trends (p>0.15) are designated by filled bl ack triangles.

................................ ...... S

- 30 Figure S.6.4.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile PM 2.5 gravimetric fine mass (FM) concentrations. Sites with statistically significant trends (p≤0.05) are designated by filled red (increasing) and blue (decreasing) triangles. Insignificant trends (p>0.15) are designated by filled black triangles.

................................ ................................ ........................... S

- 31 Figure 1.1. Class I areas of the contiguous United States. The shade coding identifies the managing agency of each Class I area.

................................ ................................ ........................ 1

- 2 Figure 1.2. Locations of IMPROVE and IMPROVE protocol sites are shown for all discontinued and current sites as of December 2010. The IMPROVE regions used for grouping the sites are indicated by shading and bold text. Urban sites included in the IMPROVE network for quality assurance purposes are identified by stars.

................................ ................................ 1

- 4 Figure 1.3. Schematic view of the IMPROVE sampler showing the four modules with separate inlets and pumps. The substrates with analyses performed for each module are also shown.

................................ ................................ ................................ ................................ ........ 1

- 15xi IMPROVE REPORT V Figure 1.4. Schematic of the version II IMPROVE sampler PM 2.5 module.

........................ 1

- 16 Figure 1.5. Detached scr een cassette.

................................ ................................ .................... 1

- 30 Figure 1.6. Attached screen cassette.

................................ ................................ .................... 1

- 30 Figure 1.7. Filter sample collected using attached screen cassette.

................................ ...... 1

- 32 Figure 1.8. Filter sample collected using detached screen cassette.

................................ ...... 1

- 32 Figure 1.9. Current and discontinued Chemical Sp eciation Network (CSN) sites (grey and orange) operated by the Environmental Protection Agency. Regions are shown as shaded areas and bold text. The sites included in the analyses in this report are shown as orange circles.

.... 1

- 37 Figure 1.10. Comparisons of 2005

– 2008 aerosol mass concentration data (μg m - 3 ) for seven collocated IMPROVE and CSN sites (see text) for adjusted organic carbon (OC), adjusted light absorbing carbon (LAC), ammonium sulfate (AS), ammonium nitrate (AN), soil, sea salt (SS), PM 2.5 grav imetric fine mass (FM), and PM 2.5 reconstructed fine mass (RCFM).

..................... 1

- 43 Figure 2.2.1a. IMPROVE (rural) 2005

– 2008 PM 2.5 ammonium sulfate (AS) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ .... 2

- 11 Figure 2.2.1b. IMPROVE and CSN 2005

– 2008 PM 2.5 ammonium sulfate (AS) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ .... 2

- 11 Figure 2.2.1c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of ammonium sulfate (AS) to PM 2.5 reconstructed fine mass (RCFM).

................................ ........ 2

- 12 Figure 2.2.1d. IMPROV E and CSN 2005

– 2008 annual mean percent (%) contributions of ammonium sulfate (AS) to PM 2.5 reconstructed fine mass (RCFM).

................................ ........ 2

- 12 Figure 2.2.2a. IMPROVE (rural) 2005

– 2008 PM 2.5 ammonium nitrate (AN) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ .... 2

- 14 Figure 2.2. 2b. IMPROVE and CSN 2005

– 2008 PM 2.5 ammonium nitrate (AN) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ .... 2

- 14 Figure 2.2.2c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of ammonium nitrate (AN) to PM 2.5 reconstructed fine mass (RCFM).

................................ ........ 2

- 15

F igure 2.2.2d. IMPROVE and CSN 2005

– 2008 annual mean percent (%) contributions of ammonium nitrate (AN) to PM 2.5 reconstructed fine mass (RCFM).

................................ ........ 2

- 15 Figure 2.2.3a. IMPROVE (rural) 2005

– 2008 PM 2.5 particulate organic matter (POM) annual
mean mass concentrat ions (μg m - 3 ).

................................ ................................ .......................... 2

- 17 Figure 2.2.3b. IMPROVE and CSN 2005

– 2008 PM 2.5 particulate organic matter (POM) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ............... 2

- 17 Figure 2.2.3c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of particulate organic matter (POM) to PM 2.5 reconstructed fine mass (RCFM).

......................... 2

- 18 Figure 2.2.3d. IMPROVE and CSN 2005

– 2008 annual mean percent (%) contributions of particulate organic matter (POM) to PM 2.5 reconstructed fine mass (RCFM).

......................... 2

- 18 Figure 2.2.4a. IMPROVE (rural) 2005

– 2008 PM 2.5 light absorbing carbon (LAC) annual mean mass concentrations (μg m - 3 ).

................................ ................................ .......................... 2

- 19xii IMPROVE REPORT V Figure 2.2.4b. IMPROVE and CSN 2005

– 2008 PM 2.5 light absorbing carbon (LAC) annual mean mass concentrations (μg m - 3 ).

................................ ................................ .......................... 2

- 20 Figure 2.2.4c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of light absorbing carbon (LAC) to PM 2.5 reconstructed fine mass (RCFM).

................................ ....... 2

- 20 Figure 2.2.4d. IMPROVE and CSN 2005

– 2008 annual mean percent (%) contributions of light absorbing carbon (LAC) to PM 2.5 reconstructed fine mass (RCFM).

............................... 2

- 21 Figure 2.2.5a. IMPROVE (rural) 2005

– 2008 PM 2.5 soil annual mean mass concentrations (μg

m - 3 ).

................................ ................................ ................................ ................................ ............ 2

- 22 Figure 2.2.5b. IMPROVE and CSN 2005

– 2008 PM 2.5 soil annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ ................................ ..... 2

- 23 Figure 2.2.5c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of soil to PM 2.5 reconstructed fine mass (RCFM).

................................ ................................ .................... 2

- 23 Figure 2.2.5d. IMPROVE and CSN 2005

– 2008 annual mean percent (%) contributions of soil to PM 2.5 reconstructed fine mass (RCFM).

................................ ................................ ................ 2

- 24 Figure 2.2.6a. IMPROVE (rural) 2005

– 2008 PM 2.5 sea salt (SS) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ ............. 2

- 25 Figure 2.2.6b. IMPROVE and CSN 2005

– 2008 PM 2.5 sea salt (SS) annual mean mass concentrations (μg m - 3 ).

................................ ................................ ................................ ............. 2

- 25 Figure 2.2.6c. IMPROVE (rural) 2005

– 2008 annual mean percent (%) contributions of sea salt to PM 2.5 reconstructed fine mass (RCFM).

................................ ................................ ......... 2

- 26 Figure 2.2.6d. IMPROVE and CSN 2005

– 2008 annual mean percent (%) contributions of sea salt (SS) to PM 2.5 reconstructed fine mass (RCFM).

................................ ................................ . 2

- 26 Figure 2.2.7a. IMPROVE (rural) 2005

– 2008 PM 2.5 annual mean gravimetric fine mass (FM) concentrations (μg m - 3 ).

................................ ................................ ................................ ............. 2

- 27 Figure 2.2.7b. IMPROVE and CSN 2005

– 2008 PM 2.5 annual mean gravimetric fine mass (FM) concentrations (μg m - 3 ).

................................ ................................ ................................ .... 2

- 28 Figure 2.2.8a. IMPROVE (rural) 2005

– 2008 PM 2.5 annual mean reconstructed fine mass (RCFM) concentrations (μg m - 3 ).

................................ ................................ .............................. 2

- 29 Figure 2.2.8.b. IMPROVE and CSN 2005

– 2008 PM 2.5 annual mean reconstructed fine mass (RCFM) concentrations (μg m - 3 ).

................................ ................................ .............................. 2

- 29 Figure 2.2.9a. IMPROVE (rural) 2005

– 2008 PM 2.5 annual mean mass difference (dM = FM

- RCFM) betwee n PM 2.5 gravimetric fine mass (FM) and reconstructed fine mass (RCFM) (μg m 3 ).

................................ ................................ ................................ ................................ ................ 2

- 30 Figure 2.2.9b. IMPROVE and CSN 2005

– 2008 PM 2.5 annual mean difference (dM = FM

- RCFM) between PM 2.5 gravimetric fine mass (FM) and reconstructed fine mass (RCFM) (μg m 3 )

. ................................ ................................ ................................ ................................ ................ 2

- 31 Figure 2.2.10. IMPROVE (rural) 2005

– 2008 annual mean coarse mass (CM = PM 10 - PM 2.5 ) (μg m - 3 ).

................................ ................................ ................................ ................................ ..... 2

- 32 Figure 2.2.11a. IMPROVE (rural) 2005

– 2008 annual mean PM 10 mass (μg m - 3 ).

............... 2

- 33xiii IMPROVE REPORT V Figure 2.2.11b. IMPROVE (rural) and EPA 2005

– 2008 annual mean PM 10 mass (μg m - 3 ). 2

- 33 Figure 3.1. Humidification factor (f(RH)) as a function of relative humidity (RH) A lognormal ammonium sulfate mass size distribution with a geometric mass mean diameter of 0.3 μm and a geometric stan dard deviation of 2.0 was assumed. A wavelength of 550 nm was used.

............ 3

- 4 Figure 3.2a. PM 2.5 reconstructed ambient annual mean light extinction coefficient for ammonium sulfate (b ext_AS , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IM PROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

......... 3

- 6 Figure 3.2b. PM 2.5 reconstructed ambient annual mean light extinction coefficient for ammonium sulfate (b ext_AS , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modi fied original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 3

- 6 Figure 3.2c. Annual mean percent contribution (%) of ambient ammonium sulfate (AS) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................................ ................ 3

- 7 Figure 3.2d. Annual mean percent contribution (%) of ambient ammonium sulfate (AS) light extinction coefficient (b ext ) to PM 2 .5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ .................. 3

- 7 Figure 3.3a. PM 2.5 reconstructed ambient annual mean light extinction co efficient for ammonium nitrate (b ext_AN , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

......... 3

- 9 Figure 3.3b. PM 2.5 reconstructed ambient annual mean light extinction coefficient for ammonium nitrate (b ext_AN , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 3

- 9

F igure 3.3c. Annual mean percent contribution (%) of ambient ammonium nitrate (AN) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................................ .............. 3

- 10 Figure 3.3d. Annual mean percent contribution (%) of ambient ammonium nitrate (AN) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................ 3

- 10 Figure 3.4a. PM 2.5 reconstructed ambient annual mean light extinction coefficient for particulate or ganic matter (POM) (b ext_POM , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............. 3

- 12 Figure 3.4b. PM 2.5 reconstructed ambient annual mean light extinction coefficie nt for particulate organic matter (POM) (b ext_POM , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................................ .............. 3

- 12xiv IMPROVE REPORT V Figure 3.4c. Annual mean percent contributio n (%) of ambient particulate organic matter (POM) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm

. ................................ ................................ .......................... 3

- 13 Figure 3.4d. Annual mean percent contribution (%) of ambient particulate organic matter (POM) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROV E algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ......... 3

- 13 Figure 3.5a. PM 2.5 reconstructed ambient annual mean light extinction coefficient for light absorbing carbon (b ext_LAC , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified origi nal” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

....... 3

- 14 Figure 3.5b. PM 2.5 reconstructed ambient annual mean light extinction coefficient for light absorbing carbon (b ext_LAC , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN s ites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............. 3

- 15 Figure 3.5c. Annual mean percent contribution (%) of ambient light absorbing carbon (LAC) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................................ .............. 3

- 15 Figure 3.5d. Annual mean percent contribution (%) of ambient light absorbing carbon (LA C) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................ 3

- 16 Figure 3.6a. PM 2.5 reconst ructed ambient annual mean light extinction coefficient for soil (b ext_soil , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ......... 3

- 17 Figure 3.6b. PM 2.5 reconstructed ambient annual mean light extinction coefficient for soil (b ext_soil , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

....... 3

- 17 Figure 3.6c. Annual mean percent contribution (%) of ambient soil light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

....... 3

- 18

F igure 3.6d. Annual mean percent contribution (%) of ambient soil light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wav elength corresponds to 550 nm.

................................ ................................ ................................ .............. 3

- 18 Figure 3.7a. PM 2.5 reconstructed ambient annual mean light extinction coefficient for sea salt (b ext_SS , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelen gth corresponds to 550 nm.

................................ ......... 3

- 19 Figure 3.7b. PM 2.5 reconstructed ambient annual mean light extinction coefficient for sea salt (b ext_SS , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text ). Wavelength corresponds to 550 nm.

...................... 3

- 20xv IMPROVE REPORT V Figure 3.7c. Annual mean percent contribution (%) of ambient sea salt (SS) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............. 3

- 20 Figure 3.7d. Annual mean percent contribution (%) of ambient sea salt (SS) light extinction coefficient (b ext ) to PM 2.5 reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ................................ .............. 3

- 21 Figure 3.8a. PM 2.5 reconstructed annual mean light extinction coeffi cient for ambient aerosol (b ext_aer , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ......... 3

- 22 Figure 3.8b. PM 2.5 reconstructed annual mean light extinction coefficien t for ambient aerosol (b ext_aer , Mm - 1 ) for 2005

– 2008 for rural IMPROVE and urban CSN sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

...................... 3

- 22 Figure 3.9a. Annual mean light extinction coefficient for coar se mass (b ext_CM , Mm - 1 ) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ................................ ......... 3

- 23 Figure 3.9b. Annual mean percent contribution (%) of coarse mass (CM) light extinction coef ficient to total reconstructed aerosol b ext for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm. Rayleigh scattering was not included in total b ext . ................................ .............................. 3

- 24 Figure 3.10. Annual mean PM 2.5 deciview (dv) for 2005

– 2008 for rural IMPROVE sites. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............. 3

- 25 Figure 4.1.1. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg

m - 3 ) for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ............................. 4

- 3 Figure 4.1.2. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m 3 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, li ght absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ............................. 4

- 4 Figure 4.1.3. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 mass concentra tions (μg m 3 ) for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absor bing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ............................. 4

- 5xvi IMPROVE REPORT V Figure 4.1.4. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m - 3 ) for Hawaii, Alaska, and the Virgin Islands. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorb ing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ..................... 4

- 6 Figure 4.1.5. Seasonal variability for IMPROVE 2005

– 2008 monthly mean ammonium sulfate (AS) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of th e triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............... 4

- 7 Figure 4.1.6. CSN 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m - 3 ) for the eastern United States. The letters on the x

- axis corres pond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area co rresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................................ ............... 4

- 8 Figure 4.1.7. CSN 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m - 3 ) for the southwestern United States. The letters on the x

- axis correspond to the m onth and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ............................. 4

- 9 Figure 4.1.8. CSN 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m - 3 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions t hat comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 4

- 10 Figure 4.1.9. CSN 2005

– 2008 regional monthly mean PM 2.5 mass concentrations (μg m - 3 ) for Hawaii and Alaska. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” m ean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites us ed in the analysis, shown as dots.

................................ ................................ ................................ ............. 4

- 11 Figure 4.1.10. Seasonal variability for CSN 2005

– 2008 monthly mean ammonium sulfate (AS) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............................... 4

- 12 Figure 4.1.11. IMPROVE 2005

– 200 8 regional monthly mean PM 2.5 reconstructed fine mass fractions for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) inxvii IMPROVE REPORT V red, particulat e organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 4

- 13 Figure 4.1.12. IMPROVE 2005

– 2008 regio nal monthly mean PM 2.5 reconstructed fine mass fractions for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 14 Figure 4.1.13. IMPROVE 2005

– 2008 regiona l monthly mean PM 2.5 reconstructed fine mass fractions for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate or ganic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 15 Figure 4.1.14. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 reconstructed fine mass fractions for Hawaii, Alaska,and the Virgin Islands. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particula te organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ............................. 4

- 16 Figure 4.1.15. Seasonal variability f or IMPROVE 2005

– 2008 monthly mean ammonium sulfate (AS) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season wi th the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 4

- 17 Figure 4.1.16. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed fine mass fractions for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) i n black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 4

- 18 Figure 4.1.17. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed fine mass fractions for the no rthwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in blac k, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 19 Figure 4.1.18. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed fine mass fractions for the southwes tern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black,xviii IMPROVE REPORT V soi l in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 20 Figure 4.1.19. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed fine mass fractions for Hawaii and Alaska. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 4

- 21 Figure 4.1.20. Seasonal variability for CSN 2005

– 2008 monthly mean ammonium sulfate (AS) reconstructed fine mass fractions. The colo r of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 4

- 22 Figure 4.2.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean ammonium nitrate (AN) mass concentrations. The color of the upward pointing triangle refers to the season with the maxi mum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............................... 4

- 23

F igure 4.2.2. Seasonal variability for CSN 2005

– 2008 monthly mean ammonium nitrate (AN) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............................... 4

- 24 Figure 4.2.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean amm onium nitrate (AN) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentra tion. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 4

- 25 Figure 4.2.4. Seasonal variability for CSN 2005

– 2008 monthly mean ammonium nitrate (AN) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 26 Figure 4.3.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean particulate organic matter (POM) mass concentrations. The color of the upward pointing triangle refers to the seaso n with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concen tration.

................................ ................................ ................................ ................................ .................... 4

- 27 Figure 4.3.2. Seasonal variability for CSN 2005

– 2008 monthly mean particulate organic matter (POM) mass concentrations. The color of the upward pointing triangle refers to the seasonxix IMPROVE REPORT V with the maximum monthly mean concentration and the downwar d pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 28 Figure 4.3.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean particulate organic matter (POM) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season wi th the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 4

- 29 Figure 4.3.4. Seasonal variability for CSN 2005

– 2008 monthly mean particulate organic
matt er (POM) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 4

- 30 Figure 4.4.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean light absorbing carbon (LAC) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 31 Figure 4.4.2. Seasonal variability for CSN 2005

– 2008 monthly mean light absorbing carbon (LAC) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum mo nthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 32 Figure 4.4.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean light absorbing carbon (LAC) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward point ing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 4

- 33 Figure 4.4.4. Seasonal variability for CSN 2005

– 2008 m onthly mean light absorbing carbon (LAC) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 4

- 34 Figure 4.5.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean fine soil mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ......... 4

- 35xx IMPROVE REPORT V Figure 4.5.2. Seasonal variability for CSN 2005

– 2008 monthly mean fine soil mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ......... 4

- 36 Figure 4.5.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean fine soil reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to th e season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 37 Figure 4.5.4. Seasonal variability for CSN 2005

– 2008 monthly mean fine soil rec onstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............................... 4

- 38 Figure 4.6.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean sea salt (SS) mass concentrations. The color of the upward pointing triangle re fers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ......... 4

- 39 Figure 4.6.2. Seasonal variability for CSN 2005

– 2008 monthly mean sea salt (SS) mass concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ......... 4

- 40 Figure 4.6.3. Seasonal variability for IMPROVE 20 05

– 2008 monthly mean sea salt (SS) reconstructed fine mass fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthl y mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 41 Figure 4.6.4. Seasonal variability for CSN 2005

– 2008 monthly mean sea salt (SS) reconstructed fine mass fractio ns. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the
magn itude of the ratio of maximum to minimum monthly mean mass concentration.

............. 4

- 42 Figure 4.7.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean PM 2.5 gravimetric fine mass (FM) concentrations. The color of the upward pointing triangle refers to the se ason with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass con centration.

............. 4

- 43 Figure 4.7.2. Seasonal variability for CSN 2005

– 2008 monthly mean PM 2.5 gravimetric fine mass (FM) concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the seasonxxi IMPROVE REPORT V with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............................... 4

- 44 Figure 4.8.1. IMPROVE 2005

– 2008 regional monthly mean coarse mass concentrations (μg

m - 3 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds to the regions that comprise the sites used in the analysis, sh own as dots.

................................ ................................ ................... 4

- 45 Figure 4.8.2. IMPROVE 2005

– 2008 regional monthly mean coarse mass concentrations (μg

m - 3 ) for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area correspo nds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 46 Figure 4.8.3. IMPROVE 2005

– 2008 regional monthly mean coarse mass concentrations (μg

m - 3 ) for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 4

- 47 Figure 4.8.4. IMPROVE 2005

– 2008 regional monthly mean coarse mass concentrations (μg

m - 3 ) for OCONUS U.S. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................................ ............. 4

- 48 Figure 4.8.5. Seasonal variability for IMPROVE 2005

– 2008 month ly mean coarse mass (CM) concentrations. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The siz e of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ......... 4

- 49 Figure 5.1.1. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients ( b ext , Mm - 1 ) for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 5

- 2 Figure 5.1.2. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients (b ext , Mm - 1 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammoni um sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the a nalysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 5

- 3 Figure 5.1.3. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients (b ext , Mm - 1 ) for the southw estern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, lightxxii IMPROVE REPORT V absorbing carbon (LAC) in black, s oil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 5

- 4 Figure 5.1.4. I MPROVE 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients (b ext , Mm - 1 ) for Hawaii, Alaska, and the Virgin Islands. The letters on the

x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown a s dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............... 5

- 5 Figure 5.1.5. Seasonal variability for 2005

– 2008 monthly mean regional IMPROVE ammonium sulfate (AS) light extinction coefficients (b ext ). The colo r of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................... 5

- 6 Figure 5.1.6. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients (b ext , Mm - 1 ) for the southwestern United States. The letters on the x

- axis correspond
to t he month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

........................ 5

- 7 Figure 5.1.7. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed light ex tinction coefficients (b ext , Mm - 1 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) i n green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wave length corresponds to 550 nm.

........................ 5

- 8 Figure 5.1.8. CSN 2005

– 2008 regional monthly mean reconstructed light extinction coefficients (b ext , Mm - 1 ) for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” me an. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites use d in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ........... 5

- 9 Figure 5.1.9. CSN 2005

– 2008 regional monthly mean PM 2.5 reconstructed light extinction coefficients (b ext , Mm - 1 ) for Hawa ii and Alaska. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions thatxxiii IMPROVE REPORT V comprise the sites used in the analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

................................ ......... 5

- 10 Figure 5.1.10. Season al variability for 2005

– 2008 monthly mean regional CSN ammonium sulfate (AS) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 11 Figure 5.1.11. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 light extinction coefficient (b ext ) fractions for Hawaii, Alaska, and the Virgin Islands. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

........... 5

- 12 Figure 5.1.12. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 light extinction coefficient (b ext ) fractions for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particula te organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ......... 5

- 13 Figure 5.1.13. IMPROVE 2005

– 2008 regi onal monthly mean PM 2.5 light extinction coefficient (b ext ) fractions for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

........... 5

- 14 Figure 5.1.14. IMPROVE 2005

– 2008 regional monthly mean PM 2.5 light extinction coefficient (b ext ) fractions for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (A N) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

........... 5

- 15 Figure 5.1.15. Se asonal variability for IMPROVE 2005

– 2008 monthly mean regional ammonium sulfate (AS) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ .......... 5

- 16 Figure 5.1.16. CSN 2005

– 2008 regional monthly mea n PM 2.5 light extinction coefficient (b ext ) fractions for the eastern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil inxxiv IMPROVE REPORT V brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 5

- 17 Figure 5.1.17. CSN 2005

– 2008 regional monthly me an PM 2.5 light extinction coefficient (b ext ) fractions for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate or ganic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 5

- 18 Figure 5.1.18. CSN 2005

– 2008 regional mont hly mean PM 2.5 light extinction coefficient (b ext ) fractions for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particul ate organic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ................... 5

- 19 Figure 5.1.19. CSN 2005

– 2008 regiona l monthly mean PM 2.5 light extinction coefficient (b ext ) fractions for Hawaii and Alaska. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. Ammonium sulfate (AS) in yellow, ammonium nitrate (AN) in red, particulate org anic matter (POM) in green, light absorbing carbon (LAC) in black, soil in brown, and sea salt in blue. The shaded area corresponds to the regions that comprise the sites used in the analysis, shown as dots.

................................ ................................ ........................... 5

- 20 Figure 5.1.20. Seasonal variability for CSN 2005

– 2008 monthly mean regional ammonium sulfate (AS) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to th e season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 21 Figure 5.2.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional ammonium nitrate (AN) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean con centration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 22 Figure 5.2.2. Seasonal variability for CSN 2005

– 2008 monthly mean regional ammonium nitrate (AN) light extinction coeffic ients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers t o the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 24 Figure 5.2.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional ammonium nitrate (AN) light extinction coefficient (b ext ) fractions. The color of the up ward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration.xxv IMPROVE REPORT V The size of the triangles refers to the magnitude of the ratio of m aximum to minimum monthly mean mass concentration.

................................ ................................ ................................ .......... 5

- 25 Figure 5.2.4. Seasonal variability for CSN 2005

– 2008 monthly mean regional ammonium nitrate (AN) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass

c oncentration.

................................ ................................ ................................ ............................. 5

- 26 Figure 5.3.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional particulate organic matter (POM) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ .......... 5

- 28 Figure 5.3.2 . Seasonal variability for CSN 2005

– 2008 monthly mean regional particulate organic matter (POM) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downwar d pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 29 Figure 5.3.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional particulate organic matter (POM) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle re fers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ........... 5

- 30 Figure 5.3.4. Seasonal variability for CSN 2005

– 2008 monthly mean reg ional particulate organic matter (POM) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with th e minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ .......... 5

- 31 Figure 5.4.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional light absorbing carbon (LAC) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentratio n. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 33 Figure 5.4.2. Seasonal variability for CSN 2005

– 2008 monthly mean regional light absorbing carbon (LAC) light extinction coefficie nts (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of thexxvi IMPROVE REPORT V triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 34 Figure 5.4.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional light absorbing carbon (LAC) light extinction coefficient (b ext ) fractions. The color of t he upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ .......... 5

- 35 Figure 5.4.4. Seasonal variability for CSN 2005

– 2008 monthly mean regional light absorbing carbon (LAC) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle re fers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 36 Figure 5.5.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional soil light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentrat ion and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 5

- 38 Figure 5.5.2. Seasonal varia bility for CSN 2005

– 2008 monthly mean regional soil light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season wit h the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 5

- 39 Figure 5.5.3. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional soil light

e xtinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 40 Figure 5.5.4. Seasonal variability for CSN 2005

– 2008 monthly mean regional soil light extinction coefficient (b ext ) fractions. The color of t he upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 42 Figure 5.6.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional sea salt (SS) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the

season w ith the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentra tion.

................................ ................................ ................................ ................................ .................... 5

- 43xxvii IMPROVE REPORT V Figure 5.6.2. Seasonal variability for CSN 2005

– 2008 monthly mean regional sea salt (SS) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the dow nward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

............. 5

- 44 Figure 5.6.3. Seasonal variability for IMPR OVE 2005

– 2008 monthly mean regional sea salt (SS) light extinction coefficients (b ext ) fraction. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the sea son with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ............................. 5

- 45 Figure 5.6.4. Seasonal variability for CSN 2005

– 2008 monthly mean regional sea salt (SS) light extinction coefficient (b ext ) fractions. The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentrati on. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 46 Figure 5.7.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional PM 2.5 aerosol light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magni tude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 47 Figure 5.7.2. Seasonal variability for CSN 2005

– 2008 monthly mean regional PM 2.5 aerosol light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean m ass concentration.

............. 5

- 48 Figure 5.8.1. IMPROVE 2005

– 2008 regional monthly mean coarse mass reconstructed light extinction coefficients (b ext , Mm - 1 ) for Hawaii, Alaska and the Virgin Islands. The letters on the

x

- axis correspond to the month and “A” correspo nds to “annual” mean. The shaded area corresponds to the regions that comprise the sites used in this analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550

nm.

................................ ................................ ................................ ................................ ............. 5

- 49 Figure 5.8.2. IMPROVE 2005

– 2008 regional monthly mean coarse mass reconstructed light extinction coefficients (b ext , Mm - 1 ) for the northwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds to the r egions that comprise the sites used in this analysis, shown as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

...................... 5

- 49 Figure 5.8.3. IMPROVE 2005

– 2008 regional monthly mean coarse mass reconstructed light extinction coefficients (b ext , Mm - 1 ) for the southwestern United States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds toxxviii IMPROVE REPORT V the regions that comprise the sites used in this analysis, show n as dots. The “modified original” IMPROVE algorithm was used (see text). Wavelength corresponds to 550 nm.

...................... 5

- 50 Figure 5.8.4. IMPROVE 2005

– 2008 regional monthly mean coarse mass reconstructed light extinction coefficients (b ext , Mm - 1 ) for the eastern Unit ed States. The letters on the x

- axis correspond to the month and “A” corresponds to “annual” mean. The shaded area corresponds to the regions that comprise the sites used in this analysis, shown as dots. The “modified original” IMPROVE algorithm was used ( see text). Wavelength corresponds to 550 nm.

...................... 5

- 51 Figure 5.8.5. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional coarse mass (CM) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downward pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 52 Figure 5.9.1. Seasonal variability for IMPROVE 2005

– 2008 monthly mean regional deciview (dv) light extinction coefficients (b ext ). The color of the upward pointing triangle refers to the season with the maximum monthly mean concentration and the downwar d pointing triangle refers to the season with the minimum monthly mean concentration. The size of the triangles refers to the magnitude of the ratio of maximum to minimum monthly mean mass concentration.

................................ ................................ ................................ ................................ .................... 5

- 53 Figure 6.1.1 . Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile sulfate ion mass concentrations.

................................ ................................ ................................ ............................. 6

- 4 Figure 6.1.2. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter sulfate ion mass concentrations.

................................ ................................ ................................ ............................. 6

- 4 Figure 6.1.3. Average winter sulfate ion mass concentrations (μg m - 3 ) for Denali, Alaska (DENA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept correspond s to the initial year of data.

................................ ................................ .......... 6

- 5 Figure 6.1.4. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile sulfate ion mass concentrations.

................................ ................................ ................................ ............................. 6

- 5 Figure 6.1.5. 90 th percentile sulfate ion mass concentrations (μg m - 3 ) for Big Bend, Texas (BIBE1). Regression re sults, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ .......... 6

- 6 Figure 6.1.6. Short

- term (2000

– 2008) trends (% yr - 1 ) in 10 th percentile sulfate ion mass concentrations.

................................ ................................ ................................ ............................. 6

- 9 Figure 6.1.7. Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter sulfate ion mass concentrations.

................................ ................................ ................................ ........................... 6

- 10 Figure 6.1.8. Average spring sulfate ion mass concentrations (μg m - 3 ) for Martha’s Vineyard, Massachusetts (MAVI1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b,
μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......................... 6

- 10xxix IMPROVE REPORT V Figure 6.1.9. Short

- term (2000

– 2008) trends (% yr - 1 ) in average spring sulfate ion mass concentrations.

................................ ................................ ................................ ........................... 6

- 13 Figure 6.1.10. Average spring sulfate ion mass concentrations (μg m - 3 ) for Hawaii Volcanoes (HAVO1). Regression res ults, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 14 Figure 6.2.1. Short

- term (2000

– 2008) trends (% yr - 1 ) in 10 th percentile nitrate ion mass concentrations.

................................ ................................ ................................ ........................... 6

- 15 Figure 6.2.2. Average winter nitrate ion mass concentrations (μg m - 3 ) for Trinity, California (TRIN1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercep t (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 15 Figure 6.2.3. Short

- term (2000

– 2008) trends (% yr - 1 ) in average fall nitrate ion mas s concentrations.

................................ ................................ ................................ ........................... 6

- 16 Figure 6.2.4. Short

- term (2000

– 2008) trends (% yr - 1 ) in 50 th percentile nitrate ion mass concentrations.

................................ ................................ ................................ ........................... 6

- 17 Figure 6.2.5. Short

- term (2000

– 2008) trends (% yr - 1 ) in average spring nitrate ion mass concentrations.

................................ ................................ ................................ ........................... 6

- 17 Figure 6.2.6. Average winter nitrate ion mass concentrations (μg m - 3 ) for Jarbidge NV (JARB1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid l ine. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 18 Figure 6.3.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 19 Figure 6.3.2. 10 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Three Sisters, Oregon (THSI1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

.. 6

- 19 Figure 6.3.3. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter total carbon (TC = organic carbon + light absorbing carbon) mass c oncentrations.

................................ ................ 6

- 20 Figure 6.3.4. Average winter total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Mount Rainier, Washington (MORA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ................................ ................................ ........ 6

- 20 Figure 6.3.5. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile total carbon (TC =
orga nic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 21 Figure 6.3.6. 90 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Bridger, Wyoming (BRID1). Regression results, including Theil slope (m , μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

.. 6

- 21xxx IMPROVE REPORT V Figure 6.3.7. Long

- term (1989

– 2008) trends (% yr - 1 ) in avera ge summer total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 22 Figure 6.3.8. Average summer total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Bridger, Wyoming (BRID1). Regression r esults, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ................................ ................................ ............ 6

- 22 Figure 6.3.9. Short

- term (20 00

– 2008) trends (% yr - 1 ) in 10 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 23 Figure 6.3.10. 10 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Th ree Sisters, Oregon (THSI1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year o f data.

................................ ................................ ................................ ................................ ............ 6

- 24 Figure 6.3.11. Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 24 Figure 6.3.12. Short

- term (2000

– 2008) trends (% yr - 1 ) in 50 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 25 Figure 6.3.13. 50 th percentile total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Hawaii Volcanoes (HAVO1). Regressi on results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ................................ ................................ ............ 6

- 25 Figure 6.3.14. Short

- ter m (2000

– 2008) trends (% yr - 1 ) in average summer total carbon (TC = organic carbon + light absorbing carbon) mass concentrations.

................................ ................ 6

- 26 Figure 6.3.15. Average summer total carbon (TC = organic carbon + light absorbing carbon) mass concentrations (μg m - 3 ) for Gates of the Mountains, Montana (GAMO1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the i nitial year of data.

................................ ................................ ................................ ..................... 6

- 26 Figure 6.4.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 28 Figure 6.4.2. 10 th percentile fine soil mass concentrations (μg m - 3 ) for Denali, Alaska (DENA1). Regression results, includ ing Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The intercept corresponds to the initial year of data.

................................ ................................ ................................ ................................ ............ 6

- 28 Figure 6.4.3. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 29 Figure 6.4.4. Average summer fine soil mass concentrations (μg m - 3 ) for Virgin Islands (VIIS1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ),xxxi IMPROVE REPORT V significance (s), and trend (t, % yr - 1 ) are included. Th e trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 29 Figure 6.4.5. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 30 Figure 6.4.6. 90 th percentile fine soil mass concentrations (μg m - 3 ) for Columbia River Gorge, Washington (CORI1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg

m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The intercept correspo nds to the initial year of data.

................................ ................................ ................................ ................................ 6

- 30 Figure 6.4.7. 90 th percentile fine soil mass concentrations (μg m - 3 ) for Denali, Alaska (DENA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 31 Figure 6.4.8. Long

- term (1989

– 2008) trends (% yr - 1 ) in average spring fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 31 Figure 6.4.9. Average spring fi ne soil mass concentrations (μg m - 3 ) for Death Valley, California (DEVA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg

m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. T he intercept corresponds to the initial year of data.

................................ ................................ . 6

- 32 Figure 6.4.10. Short

- term (2000

– 2008) trends (% yr - 1 ) in 10 th percentile fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 33 Figure 6.4.11. Short

- term (2000

– 2008) trends (% yr - 1 ) in 50 th percentile fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 33 Figure 6.4.12. Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 34 Figure 6.4.13. Average winter fine soil mass concentrations (μg m - 3 ) for Big Bend, Texas (BIBE1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 34 Figure 6.4.14. Short

- term (2000

– 2008) trends (% yr - 1 ) in 90 th percentile fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 35 Figure 6.4.15. Short

- term (2000

– 2008) trends (% yr - 1 ) in average fall fine soil mass concentrations.

................................ ................................ ................................ ........................... 6

- 35 Figure 6.4.16. Average fall fine soil mass concentrations (μg m - 3 ) for Zion Canyon, Utah (ZICA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 36

Fi gure 6.4.17. Fall fine soil mass concentrations (μg m - 3 ) for Mesa Verde, Colorado (MEVE1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 36xxxii IMPROVE REPORT V Figure 6.5.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 37 Figure 6.5.2. 10 th percentile PM 2.5 gravimetric fine mas s (FM) concentrations (μg m - 3 ) for Craters of the Moon, Idaho (CRMO1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The i ntercept corresponds to the initial year of data.

................................ ......... 6

- 38 Figure 6.5.3. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 38 Figure 6.5.4. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 39 Figure 6.5.5. 90 th percentile PM 2.5 gravimetric fine mass (FM) concentrations (μg m - 3 ) for Sawtooth, Idaho (SAWT1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), signific ance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......................... 6

- 40 Figure 6.5.6. Long

- term (1989

– 2008) trends (% yr - 1 ) in average summer PM 2.5 gravimetric fine mass (FM) conc entrations.

................................ ................................ ................................ .. 6

- 40 Figure 6.5.7. Short

- term (2000

– 2008) trends (% yr - 1 ) in 90 th percentile PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 41 Figure 6.5.8. 90 th percentile PM 2.5 gravimetric fine mass (FM) concentrations (μg m - 3 ) for Hawaii Volcanoes (HAVO 1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......................... 6

- 41 Figure 6.5.9 . Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 42 Figure 6.5.10. Average winter PM 2.5 gravimetric fine mass (FM) concentrations (μg m - 3 ) for Starkey, Oregon (STAR1). Regression results, includi ng Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......................... 6

- 42 Figure 6.5.11. Average winter PM 2.5 gravimetric fine mass (FM) concentrations (μg m - 3 ) for Trapper Creek, Alaska (TRCR1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted

as a s olid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 43 Figure 6.5.12. Short

- term (2000

– 2008) trends (% yr - 1 ) in average fall PM 2.5 gravimetric fine mass (FM) concentrations.

................................ ................................ ................................ ......... 6

- 44 Figure 6.5.13. Average fall PM 2.5 gravimetric fine mass (FM) concentrations (μg m - 3 ) for Zion Canyon, Utah (ZICA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b,
μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresp onds to the initial year of data.

................................ ......................... 6

- 44 Figure 6.6.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 45xxxiii IMPROVE REPORT V Figure 6.6.2. 10 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Mou nt Zirkel, Colorado (MOZI1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year o f data.

................................ ......... 6

- 45 Figure 6.6.3. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 46 Figure 6.6.4. Average winter coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Snoqualmie Pass, Washington (SNPA1). Regression results, including Theil slope (m, μg m - 3 yr 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

............................. 6

- 46 Figure 6.6.5. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 47 Figure 6.6.6. 90 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Yosemite, California (YOSE1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 47 Figure 6.6.7. 90 th percentile coars e mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Snoqualmie Pass, Washington (SNPA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend (t, % yr - 1 ) are included. The intercept corresponds t o the initial year of data.

................................ ................................ ....................... 6

- 48 Figure 6.6.8. Long

- term (1989

– 2008) trends (% yr - 1 ) in average summer coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 48 Figure 6.6.9. Short

- term (2000

– 2008) trends (% yr - 1 ) in 90 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 49 Figure 6.6.10. 90 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Monture, Montana (MONT1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t , % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 49 Figure 6.6.11. Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 50 Figu re 6.6.12. Average winter coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Hoover, California (HOOV1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The t rend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 50 Figure 6.6.13. Short

- term (2000

– 2008) trends (% yr - 1 ) in 50 th percentile coarse mass (CM = PM 10 - PM 2.5 ) concentrations.

................................ ................................ ................................ .... 6

- 51 Figure 6.6.14. Short

- term (2000

– 2008) trends (% yr - 1 ) in average summer coarse mass (CM = PM 10 - PM 2.5 ) concentrations

................................ ................................ ................................ ..... 6

- 51 Figure 6.6.15. Average summer coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Indian Gardens, Arizona (INGA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ),xxxiv IMPROVE REPORT V intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 52 Figure 6.6.16. Average summer coarse mass (CM = PM 10 - PM 2.5 ) concentrations (μg m - 3 ) for Olympic, Washington (OLYM1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......... 6

- 52 Figure 6.7.1. Long

- term (1989

– 2008) trends (% yr - 1 ) in 10 th percentile PM 10 gravimetric mass concentrations.

................................ ................................ ................................ ........................... 6

- 53 Figure 6.7.2. Long

- term (1989

– 2008) trends (% yr - 1 ) in average winter PM 10 gravimetri c mass concentrations.

................................ ................................ ................................ ........................... 6

- 54 Figure 6.7.3. Average winter PM 10 gravimetric mass concentrations (μg m - 3 ) for Snoqualmie Pass, Washington (SNPA1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (s), and trend ( t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ......................... 6

- 54 Figure 6.7.4. Long

- term (1989

– 2008) trends (% yr - 1 ) in 90 th percentile PM 10 gravimetric mass concentrations.

................................ ................................ ................................ ........................... 6

- 55 Figure 6.7.5. Long

- term (1989

– 2008) trends (% yr - 1 ) in average summer PM 10 gravimetric mass concentrations.

................................ ................................ ................................ .................. 6

- 55 Figure 6.7.6. Short

- term (2000

– 2008) trends (% yr - 1 ) in 10 th percentile PM 10 gravimetric mass concentrations.

................................ ................................ ................................ ........................... 6

- 56 Figure 6.7.7. Short

- term (2000

– 2008) trends (% yr - 1 ) in average winter PM 10 gravimetric mass concentrations.

................................ ................................ ................................ ........................... 6

- 57 Figure 6.7.8. Average winter PM 10 gravimetric mass concentrations (μg m - 3 ) for Bondville, Illinois (BOND1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept ( b, μg m 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 57 Figure 6.7.9. Short

- term (2000

– 2008) trends (% yr - 1 ) in 90 th percentile PM 10 gravimetri c mass concentrations.

................................ ................................ ................................ ........................... 6

- 58 Figure 6.7.10. Short

- term (2000

– 2008) trends (% yr - 1 ) in average fall PM 10 gravimetric mass concentrations.

................................ ................................ ................................ ........................... 6

- 58 Figure 6.7.11. Average fall PM 10 gravimetric mass concentrations (μg m - 3 ) for Gila, New Mexico (GICL1). Regression results, including Theil slope (m, μg m - 3 yr - 1 ), intercept (b, μg m - 3 ), significance (p), and trend (t, % yr - 1 ) are included. The trend line is plotted as a solid line. The intercept corresponds to the initial year of data.

................................ ................................ ........ 6

- 59 Figure 6.7.12. Split

- image of visibility conditions in Linville Gorge, NC (LIVO) for 50 th percentile speciated aerosol levels in 2000 (left

- side) and 2008 (right

- side). Images were generated using WinHaze 2.9.9.

................................ ................................ ................................ 6

- 60 Figure 7.1. Schematic showing urban sources of aerosol concentrations and their impact on surrounding rural concentrations. An arbitrary concentration scale is on the y

- axis and distance isxxxv IMPROVE REPORT V on the x

- axis. The concentrations levels depicted in orange repres ent levels above a rural background, depicted as blue.

................................ ................................ ................................ ...... 7

- 2 Figure 7.2.1. Interpolated annual mean ammonium sulfate (AS) concentrations (μg m - 3 ) for the rural IMPROVE network for 2005

– 2008. IMPROVE site locations are shown as black circles.

................................ ................................ ................................ ................................ .......... 7

- 5 Figure 7.2.2 . Interpolated annual mean ammonium sulfate (AS) concentrations (μg m - 3 ) for the rural IMPROVE and urban CSN networks for 2005

– 2008. IMPROVE site locations are shown as black circles, CSN sites are shown as black triangles, and urban IMPROVE sites are show n as magenta diamonds.

................................ ................................ ................................ ....... 7

- 5 Figure 7.2.3. Interpolated ratios of urban (CSN) to rural (IMPROVE) annual mean ammonium sulfate (AS) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ ................................ ... 7

- 6 Figure 7.2.4. Interpolated differences (μg m - 3 ) in urban (CSN) to rural (IMPROVE) annual mean ammonium sulfate (AS) concentrations for 2005

– 2008. IMPROVE sites are shown as circ les, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ .. 7

- 7 Figure 7.3.1. Interpolated annual mean ammonium nitrate (AN) concentrations (μg m - 3 ) for the rural IMPROVE netw ork for 2005

– 2008. IMPROVE site locations are shown as black circles.

................................ ................................ ................................ ................................ .......... 7

- 8 Figure 7.3.2. Interpolated annual mean ammonium nitrate (AN) concentrations (μg m - 3 ) for the rural IMPROVE and urban CSN networks for 2005

– 2008. IMPROVE site locations are shown as b lack circles, CSN sites are shown as black triangles, and urban IMPROVE sites are shown as magenta diamonds.

................................ ................................ ................................ ....... 7

- 8 Figure 7.3.3. Interpolated ratios of urban (CSN) to rural (IMPROVE) annual mean ammonium nitrate (AN) concentrations for 2005

– 2008. IMPROVE sit es are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ ................................ ... 7

- 9 Figure 7.3.4. Interpolated differences (μg m - 3 ) in urban (CSN) to rural (IMPROVE) annual

me an ammonium nitrate (AN) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ 7

- 10 Figure 7.4.1. Interpolat ed annual mean particulate organic matter (POM) concentrations (μg

m - 3 ) for the rural IMPROVE network for 2005

– 2008. IMPROVE site locations are shown as black circles.

................................ ................................ ................................ .............................. 7

- 11 Figure 7.4.2. Interpolated annual mean particulate organic matter (POM) concentrations (μg

m - 3 ) for the rural IMPROVE and urban CSN networks for 2005

– 2008. IMPROVE site locations are shown as black circles, CSN sites are shown as black triangles, and urban IMPROVE sites are shown as magenta diamonds.

................................ ................................ ............................... 7

- 12 Figure 7.4.3. Interpo lated ratios of urban (CSN) to rural (IMPROVE) annual mean particulate organic matter (POM) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSNxxxvi IMPROVE REPORT V sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ ....................... 7

- 13 Figure 7.4.4. Interpolated differences (μg m - 3 ) in urban (CSN) to rural (IMPROVE) annual mean particulate organic matter (POM) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IM PROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................ 7

- 14 Figure 7.5.1. Interpolated annual mean light absorbing carbon (LAC) concentrations (μg m - 3 ) for the rural IMPROVE network for 2005

– 2008 . IMPROVE site locations are shown as black circles.

................................ ................................ ................................ ................................ ........ 7

- 15 Figure 7.5.2. Interpolated annual mean light absorbing carbon (LAC) concentrations (μg m - 3 ) for the rural IMPROVE and urban CSN networks for 2005

– 2008. IMPROVE site locations are shown as black circ les, CSN sites are shown as black triangles, and urban IMPROVE sites are shown as magenta diamonds.

................................ ................................ ................................ ..... 7

- 15 Figure 7.5.3. Interpolated ratios of urban (CSN) to rural (IMPROVE) annual mean light absorbing carbon (LAC) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ .............. 7

- 16 Figure 7.5.4. Interpolated differences (μg m - 3 ) in urban (CSN) to rural (IMPROVE) annua l mean light absorbing carbon (LAC) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ....................... 7

- 17 Figure 7.6.1. Interpolated annual mean PM 2.5 gravimetric fine mass (FM) concentrations (μg

m - 3 ) for the rural IMPROVE network for 2005

– 2008. IMPROVE site locations are shown as black circles.

................................ ................................ ................................ .............................. 7

- 18 Figure 7.6.2. Interpolated annual mean PM 2.5 gravimetric fine mass (FM) concentrations (μg

m - 3 ) for the rural IMPROVE and urban CSN networks for 2005

– 2008. IMPROVE site locations are shown as black circles, CSN sites are shown as black triangles, and urban IMPROVE sites are shown as magenta diamonds.

................................ ................................ ............................... 7

- 18 Figure 7.6.3. Interpo lated ratios of urban (CSN) to rural (IMPROVE) annual mean PM 2.5 gravimetric fine mass (FM) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IMPROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................................ .............. 7

- 19 Figure 7.6.4. Interpolated differences (μg m - 3 ) in urban (CSN) to rural (IMPROVE) annual mean PM 2.5 gravimetric fine mass (FM) concentrations for 2005

– 2008. IMPROVE sites are shown as circles, CSN sites with an IM PROVE monitor within 150 km are depicted as squares, and CSN sites not used in the analyses are shown as triangles.

................................ ................ 7

- 20 Figure 7.7.1(a). Comparisons of 2005

– 2008 annual mean IMPROVE rural concentration (interpolated) on the x

- axis and CSN urban concentrat ion (data) on the y

- axis for ammonium sulfate (AS, yellow), ammonium nitrate (AN, red), particulate organic matter (POM, green), and light absorbing carbon (LAC, black). Concentrations are in μg m - 3

. ................................ ......... 7

- 21 Figure 7.7.1(b). Same as part (a) but with a logari thmic scale.

................................ ............. 7

- 21xxxvii IMPROVE REPORT V Figure 8.1. Location of the twelve urban sites with collocated IMPROVE and CSN carbon measurements and the time period the samplers were operating.

................................ ................ 8

- 6 Figure 8.2. Comparison of CSN TC and IMPROVE TC c oncentrations from collocated monitors for 2005

– 2006 data. The data are color coded based on the CSN sampler. The regression line is for the Met One data.

................................ ................................ ....................... 8

- 7 Figure 8.3. Comparison of CSN EC and IMPROVE EC concentrations from collocated monitors for 20 05

– 2006 data. The data are color coded based on the CSN sampler. The regression line is for the Met One data.

................................ ................................ ....................... 8

- 8 Figure 8.4. The CSN and IMPROVE TC, OC, and EC concentrations for all collocated IMPROVE and CSN Met One samplers that collected data in 200 5 and 2006. The lighter data points are for the reported CSN carbon concentrations and the darker data points are for the adjusted CSN carbon concentrations.

................................ ................................ ........................ 8

- 12 Figure 8.5. Stacked bar charts showing average concentrations of each species for all and each season for IMPROVE, CSN suburban, and CSN center city.

................................ ........... 8

- 16 Figure 8.6. Temporal plot of PM 2.5 − PM 2.5avg and the percent difference between reconstructed and gravimetric mass for Brigantine National Wildlife Refuge. The red line is a sinusoidal cur ve fit to the percent difference between reconstructed and gravimetric mass.

.... 8

- 18 Figure 8.7. Average percent seasonal variability (b 2 ) and percent difference (b 1 ), as represented by equation 8.13, between reconstructed and gravimetric mass for the IMPROV E and CSN monitoring networks. Green represents a positive value while red represents a negative bias.

................................ ................................ ................................ ................................ ............ 8

- 19 Figure 8.8. Average fractional increase in sulfate and nitrate mass, a 1 , due to retained water for the IMPROVE and CSN monitoring networks.

................................ ................................ ... 8

- 25

F igure 8.9. Average fraction of nitrate volatilized from a Teflon filter, (1

– a 2 /a 1 ), for the IMPROVE and CSN monitoring networks.

................................ ................................ ............... 8

- 25 Figure 8.10. Average Roc factor, a 3 , for the IMPROVE and CSN monitoring networks.

... 8

- 25 Figure 8.11. The estimated aver age difference between gravimetric and assumed forms of the various aerosol species contributing to PM 2.5 for IMPROVE. The differences are estimated as 1.375*SO 4 (a 1 – 1), 1.29*NO 3 (a 2 – 1), OC*(a 3 – 1.8), and Other*(a 4 – 1) for sulfates, nitrates, organic s, and Other, respectively.

................................ ................................ .............................. 8

- 26 Figure 8.12. The estimated average difference between gravimetric and assumed forms of the various aerosol species contributing to PM 2.5 for CSN center city. The differences are estimated as 1.375*SO 4 (a 1 – 1), 1.29*NO 3 (a 2 – 1), OC*(a 3 – 1.8), and Other*(a 4 – 1) for sulfates, nitrates, organics, and Other, respectively.

................................ ................................ .............................. 8

- 26 Figure 8.13. The estimated average difference between gravimetric and assumed forms of the various aerosol species contributing to PM 2.5 for CSN sub urban. The differences are estimated as 1.375*SO 4 (a 1 – 1), 1.29*NO 3 (a 2 – 1), OC*(a 3 – 1.8), and Other*(a 4 – 1) for sulfates, nitrates, organics, and Other, respectively.

................................ ................................ .............................. 8

- 26 Figure 8.14. Average difference between gravimetric and estimated true PM 2.5 mass concentration for the IMPROVE and CSN datasets (see equation 8.16).

................................ . 8

- 28xxxviii IMPROVE REPORT V Figure 8.15. Average difference between reconstructed and estimated true PM 2.5 concentrations for the IMPROVE and CSN datasets (see equation 8.17).

................................ 8

- 29 Figure 8.16. Seasonal and spatial variability in difference between gravimetric and true mass concentration (PM 2.5 – TPM 2.5 ) for the CSN monitoring network. Green color refers to positive and red to negative numbers.

................................ ................................ ................................ ..... 8

- 30 Figure 8.17. Seasonal and spatial variability in differ ence between gravimetric and true mass concentration (PM 2.5 – TPM 2.5 ) for the IMPROVE monitoring network. Green color refers to positive and red to negative numbers.

................................ ................................ ........................ 8

- 31 Figure 8.18. Seasonal and spatial variability in difference between true and reconst ructed mass concentration (TPM 2.5 – RPM 2.5 ) for the CSN monitoring network. Green color refers to positive and red to negative numbers.

................................ ................................ ........................ 8

- 32 Figure 8.19. Seasonal and spatial variability in difference between true and reconstructed mass concentration (TPM 2.5 – RPM 2.5 ) for the IMPROVE monitoring network. Green color refers to positive and red to negative numbers.

................................ ................................ ......... 8

- 33 Figure 9.2.1. Depiction of the conceptual uniform rate of progress (URG) glide path (EPA, 1999).

................................ ................................ ................................ ................................ ........... 9

- 3 Figur e 9.2.2. Depiction of realistic uniform rate of progress (URG) glide path (Husar, 2003).

................................ ................................ ................................ ................................ ...................... 9

- 3 Figure 9.3.1. Fraction of dv uniform rate of progress (URP) from the baseline (2000

– 2004) to period 1 (2005

– 2009) for the 20% worst visibility days at 107 of the 1 10 IMPROVE regional haze tracking sites. Brown circles indicate degradation in the worst 20% visibility days, while blue circles represent improvement in worst 20% visibility days. The two darkest shades of blue indicate progress that is at or better than the 2009 point value on the slope of the nominal URP line

. ................................ ................................ ................................ ................................ ............... 9

- 7 Figure 9.3.2. Absolute change in dv from the baseline (2000

– 2004) to period 1 (2005

– 2009) for the 20% worst visibility days at 107 of the 110 IMPROVE regional haze tracking sites. Brown circle s indicate degradation in the worst 20% visibility days, while blue circles represent improvement in worst 20% visibility days.

................................ ................................ ................. 9

- 8 Figure 9.3.3. Absolute change in dv from the baseline (2000

– 2004) to period 1 (2005

– 2009) for the 20% best visibility days at 107 of the 110 IMPROVE regional haze tracking sites. Brown circles indicate degradation in the best 20% visibility days, while blue circles represent improvement in best 20% visibility days.

................................ ................................ .................... 9

- 9 Figure 9.3.4. Absolute change in annual mean dv from the b aseline (2000

– 2004) to period 1 (2005

– 2009) at 107 of the 110 IMPROVE regional haze tracking sites. Brown circles indicate degradation in annual mean dv, while blue circles represent improvement in annual mean dv.

. 9

- 9 Figure 9.3.5. Fraction of hypothetical ammonium sulfate uniform rate of progress (URP) for the 20% worst visibility days at 107 of the 110 IMPROVE regional haze tracking sites from the baseline (2000

– 2004) to period 1 (2005

– 2009). Brown circles indicate degradation in the worst 20% visibility days due to ammonium sulfate extinction, while blue circles represent improvement in worst 20% visibility days due to ammonium sulfate extinction. Only the two darkest blue colored circles indicate progress that is at or better than the hypothetical ammo nium sulfate extinction 2009 point value on the slope of the nominal URP line

. ............................... 9

- 11xxxix IMPROVE REPORT V Figure 9.3.6. Fraction of hypothetical ammonium nitrate uniform rate of progress (URP) for the 20% worst visibility days at 107 of the 110 IMPROVE regional haze tracking si tes from the baseline (2000

– 2004) to period 1 (2005

– 2009). Brown circles indicate degradation in the worst 20% visibility days due to ammonium nitrate extinction, while blue circles represent improvement in worst 20% visibility days due to ammonium nitrat e extinction. Only the two darkest blue colored circles indicate progress that is at or better than the hypothetical ammonium sulfate extinction 2009 point value on the slope of the nominal URP line

. ............................... 9

- 12 Figure 9.3.7. Change in annual mean ammonium nitra te extinction (b ext_AN , Mm - 1 ) at 107 of the 110 IMPROVE regional haze tracking sites from the baseline (2000

- 2004) to period 1 (2005

- 2009). Brown circles indicate an increase of the annual mean b ext_AN , while blue circles represent decreases in annual mean b ext_AN
. ................................ ................................ .............................. 9

- 13 Figure 9.3.8. Change in annual mean ammonium sulfate extinction (b ext_AS , Mm - 1 ) at 107 of the 110 IMPROVE regional haze tracking sites from the baseline (2000

– 2004) to period 1 (2005

– 2009). Brown circles indicate an increase of the annual me an b ext_AS , while blue circles represent decreases in annual mean b ext_AS
. ................................ ................................ ............... 9

- 13 Figure 9.4.1.1a. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate organic mass (POM) for the baseline (2000

– 2004) , period 1 (2005

– 2009), and 2064 natural conditions estimates for the worst 20% visibility days at Boundary Waters Canoe Area Wilderness, MN. Values of b ext for other species, including elemental carbon (EC), soil, coarse mass and sea salt are listed in th e table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

............ 9

- 15 Figure 9.4.1.1b. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate organ ic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the best 20% visibility days at Boundary Waters Canoe Area Wilderness, MN. Values of b ext for other species, including elemental carbon (EC), soil, coarse mass and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

.............................. 9

- 15 Figure 9.4.1.2a. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO 4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext) and sea salt (seasalt_bext) for 2001 Boundary Waters Canoe Area (BOWA1). Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 16 Figure 9.4.1.2b. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext) and sea salt (seasalt_bext) for 2005 Boundary Waters Canoe Area (BOWA1). Wo rst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 16 Figure 9.4.2.1a. Deciview and light extinction coefficients (b ext , Mm - 1 ) for amm onium sulfate, ammonium nitrate, and particulate organic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the worst 20% visibility days at Great Smoky Mountains NP, TN and Joyce Kilmer

- Slickrock WA, N C. Values of b ext for otherxl IMPROVE REPORT V species, including elemental carbon (EC), soil, coarse mass and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 18 Figure 9.4.2.1b. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate organic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the best 20% visibility days at Great Smoky Mountains NP, TN and Joyce Kilmer

- Slickrock WA, NC. Values of b ext for other species, including elemental carbon (EC), soil, coarse mass and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colost ate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 18 Figure 9.4.2.2a. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental ca rbon (EC_bext), soil (soil_bext) and sea salt (seasalt_bext) for 2001 Great Smoky Mountains NP, TN (GRSM1) and Joyce Kilmer

- Slickrock WA, NC. Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B ” (from http://views.cira.colostate.edu/web/Composition/ ).

... 9

- 19 Figure 9.4.2.2b. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_ bext), elemental carbon (EC_bext), soil (soil_bext) and sea salt (seasalt_bext) for 2008 at Great Smoky Mountains NP, TN (GRSM1) and Joyce Kilmer

Slickrock WA, NC. Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% da ys are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 19 Figure 9.4.3.1a. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate organic mass (POM) for the baseline (200 0

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the worst 20% visibility days at Mesa Verde NP, CO. Values of b ext for other species, including elemental carbon (EC), soil, coarse mass, and sea salt are listed in the table below th e graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 21 Figure 9.4.3.1b. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate organic mass (POM) fo r the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the best 20% visibility days at Mesa Verde NP, CO. Values of b ext for other species, including elemental carbon (EC), soil, coarse mass, and sea salt are listed in the table below the graph. (Data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 21 Figure 9.4.3.2a. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea salt (seasalt_bext) for 2004 Mesa Verde NP, CO. Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 24 Figure 9.4.3.3b. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_b ext), ammonium nitrate (ammNO3f_bext), particulate organic matterxli IMPROVE REPORT V (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea salt (seasalt_bext) for 2008 Mesa Verde NP, CO. Worst 20% days are marked with a “W” above the bar f or that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 24 Figure 9.4.4.1a. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate o rganic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the worst 20% visibility days at Hell’s Canyon WA, OR/ID. Values of b ext for other species, including elemental carbon (EC), soil,
coarse mass, and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 26 Figure 9.4.4.1b. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium n itrate, and particulate organic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the best 20% visibility days at Hell’s Canyon WA, OR/ID. Values of b ext for other species, including elemental carbon ( EC), soil, coarse mass, and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 26 Figure 9.4.4.2a. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium su lfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea salt (seasalt_bext) for 2004 Hells Canyon, ID (HECA1). Worst 20% days are marked wit h a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 27 Figure 9.4.4.2b. Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammo nium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea salt (seasalt_bext) for 2006 Hells Canyon, ID (HECA1). Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 27 Figure 9.4.5.2a. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammonium nitrate, and particulate orga nic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the worst 20% visibility days at Agua Tibia Wilderness , CA. Values of b ext for other species, including elemental carbon (EC), soil,

coarse ma ss, and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 31 Figure 9.4.5.2b. Deciview and light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate, ammoni um nitrate, and particulate organic mass (POM) for the baseline (2000

– 2004), period 1 (2005

– 2009), and 2064 natural conditions estimates for the best 20% visibility days at Agua Tibia Wilderness , CA. Values of b ext for other species, including element al carbon (EC), soil, coarse mass, and sea salt are listed in the table below the graph (data and graphs obtained at http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 31 Figure 9.4.5.3a. Class I Area

– - Daily light extinction coefficients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea saltxlii IMPROVE REPORT V (seasalt_bext) for 2002 at Agua Tibia Wilderness , CA (AGTI1). Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 32 Figure 9.4.5.3b. Class I Area

– - Daily light extinction coeffi cients (b ext , Mm - 1 ) for ammonium sulfate (ammSO4f_bext), ammonium nitrate (ammNO3f_bext), particulate organic matter (OMCf_bext), coarse mass (CM_bext), elemental carbon (EC_bext), soil (soil_bext), and sea salt (seasalt_bext) for 2008 at Agua Tibia Wilder ness , CA (AGTI1). Worst 20% days are marked with a “W” above the bar for that day, and similarly, best 20% days are marked with a “B” (from http://views.cira.colostate.edu/web/Composition/ ).

................................ ................................ ... 9

- 32 Figure 10.1. Schematic of the particle generation, mixing, and sampling system used to make reference materials. A solution is atomized and the resulting particles are dried and mixed with clean, dry air in the mixing chamber. The suspended particles are drawn through an IMPROVE PM 2.5 sampler and collected on 25 mm Teflon® filters. Relative humidity (RH) is measured in three locations to ensure that particles are anhydrous.

................................ .............................. 10

- 2 Figure 10.2. Photograph of the aerosol generation system.

................................ .................. 10

- 2 Figure 10.3. Sulfur (S) mass measurements from ion chromatography (IC) compared to gravimetric analysis for ammonium sulfate and potassium sulfate reference materials. The linear regressions (with 95 th percentile confidence levels for the slope and intercept) for each reference material are given on the figure and show the good agreement between sulfur from IC and gravimetric analysis.

................................ ................................ ................................ .................. 10

- 4 Figure 11.1. Study trailer show ing aerosol sampling equipment. The CASTNET, Met tower, IMPROVE, URG, and passive samplers are shown from left to right.

................................ ..... 11

- 2 Figure 11.2. URG sampler with the NH 3 backup denuder at top and filter pack, NH 3 primary denuder, HNO 3 denuder, and PM 2.5 cyclone at bottom. Note the top of the sampler is the outlet and the bottom of the sampler is the inlet.

................................ ................................ ................. 11

- 3 Figure 11.3. IMPROVE sampler filter cassette with additional screen and spacer for NH 3 collection. The sampler includes 1) cassette filter holder, 2) Tefl on spacer, 3) Teflon

- coated support grid, and 4) top of cartridge assembly.

................................ ................................ ......... 11

- 4 Figure 11.4. IMPROVE sampler channel B with sample cassette installed.

........................ 11

- 4 Figure 11.5. CASTNET filter pack ready for deployment (left) and a disassembled filter pack (right)

. ................................ ................................ ................................ ................................ ........ 11

- 5 Figure 11.6. Regular (left) and modified (right) CASTNET filter packs in the sample holder.

................................ ................................ ................................ ................................ .................... 11

- 5 Figure 11.7. Passive samplers deployed in the field. The Ogawa sampler is on the left, and the Radiello sampler is on the right.

................................ ................................ ................................ 11

- 6 Figure 11.8. Compa risons of sulfate ion (SO 4 2

- ) concentrations from the regular IMPROVE (RegIMP), modified IMPROVE (ModIMP), and URG samplers during fall 2008. Mean sulfate ion concentrations (μg m - 3 ) for each sampler are reported.

................................ ....................... 11

- 7 Figure 11.9. Comparisons of nitrate i on (NO 3 - ) concentrations from the regular IMPROVE (RegIMP), modified IMPROVE (ModIMP), and URG samplers during fall 2008. Mean nitrate ion concentrations (μg m - 3 ) for each sampler are reported.

................................ ....................... 11

- 8xliii IMPROVE REPORT V Figure 11.10. Comparisons of ammonium ion (NH 4 + ) concentr ations from the regular IMPROVE (Regular IMP), modified IMPROVE (Modified IMP), and URG samplers during fall 2008. Mean ammonium ion concentrations (μg m - 3 ) for each sampler are reported.

................ 11

- 9 Figure 11.11. Comparisons of ammonia (NH 3 ) concentrations from the modified IMPROVE (Modified IMP) and URG samplers during fall 2008. Mean ammonia concentrations (μg m - 3 ) for each sampler are reported.

................................ ................................ ................................ ....... 11

- 10 Figure 11.12. Comparisons of NH x (NH 3 + NH 4 + ) concentrations from the modified IMPROVE (Mod IMP) and URG sample rs during fall 2008. Mean NH x concentrations (μg m - 3 ) for each sampler are reported.

................................ ................................ ................................ .. 11

- 11 Figure 11.13. Comparisons of NH x (NH 3 + NH 4 + ) concentrations from the modified IMPROVE (IMP) and URG samplers during spring 2010. Mean NH x concentrations (μg m - 3 ) fo r each sampler are reported.

................................ ................................ ................................ ....... 11

- 12 Figure 11.14. Comparisons of sulfate ion (SO 4 2

- ) concentrations from the modified CASTNET (Mod CASTNET), regular CASTNET (Reg CASTNET), and URG samplers during fall 2008. Mean sulfate ion concentrations (μg m - 3 ) for each sampler are reported.

............................... 11

- 13 Figure 11.15. Comparisons of nitrate ion (NO 3 - ) concentrations from the modified CASTNET (Mod CASTNET), regular CASTNET (Reg CASTNET), and URG samplers during fall 2008. Mean nitrate ion concentrations (μg m - 3 ) for each sampler are reported.

................................ 11

- 14 Figure 11.16. Comparisons of nitric acid (HNO 3 ) concentrations from the modified CASTNET (Mod CASTNET), regular CASTNET (Reg CASTNET), and URG samplers during fall 2008. Mean nitric acid concentrations (μg m - 3 ) for each sampler are repo rted.

................ 11

- 15 Figure 11.17. Comparisons of total oxidized nitrogen concentrations (NO 3 - + HNO 3 ) from the modified CASTNET (Mod CASTNET), regular CASTNET (Reg CASTNET), and URG samplers during fall 2008. Total oxidized nitrogen concentrations (μg m - 3 ) for eac h sampler are reported.

................................ ................................ ................................ ................................ ... 11

- 16 Figure 11.18. Comparisons of ammonium ion (NH 4 + ) concentrations from the modified CASTNET (Mod CASTNET), regular CASTNET (Reg CASTNET), and URG samplers during fall 2008. Ammonium concentrations (μg m - 3 ) for each sampler are r eported.

....................... 11

- 17 Figure 11.19. Comparisons of ammonia (NH 3 ) concentrations from the modified CASTNET (Mod CASTNET), and URG samplers during fall 2008. Ammonia concentrations (μg m - 3 ) for each sampler are reported.

................................ ................................ ................................ ....... 11

- 18 Figure 11.20. Comparisons of total reduced inorganic nitrogen (NH x = NH 3 + NH 4 + ) concentrations from the modified CASTNET (Mod CASTNET) and URG samplers for 2008. NH x (μg m - 3 ) for each sampler are reported.

................................ ................................ ........... 11

- 19 Figure 11.21. Comparison of weekly ammonia (NH 3 ) concentrations (μg m - 3 ) from URG and CASTNET samplers and 2

- week concentrations from the Radiello and Ogawa passive samplers during 2008.

................................ ................................ ................................ ............................. 11

- 20xliv IMPROVE REPORT V LIST OF TABLES Table S.2.2. Comparisons between collocated IMPROVE and CSN sites for all data from 2005 through 2008. Species include organic carbon (OC), light absorbing carbon (LAC), ammonium sulfate (AS), ammonium nitrate (AN), soil, sea salt, PM 2.5 gravimetric fine mass (FM), and PM 2.5 reconstructed fine mass (RCFM). “OC unadj ” and “LAC unadj ” refer to comparisons between unadjusted CSN carbon data and IMPROVE carbon data; “OC adj ” and “LAC adj ” refer tocomparisons between adjusted CSN carbon and IMPROVE carbon data.

...... S

- 7 Table 1.1. Currently operating and discontinued IMPROVE particulate monitoring sites. The sites are grouped by region, as displayed in Figure 1.2.

................................ .............................. 1

- 5 Table 1.2. Class I areas and the represen tative monitoring site

. . ................................ .......... 1

- 11

Table 1.4. Transmissometer receiver and transmitter locations.

................................ ........... 1

- 21 Table 1.5. IMPROVE nephelometer network site locations.

................................ ................ 1

- 23 Table 1.6. Updated flow rate

- related validation flag definitions and application criteria.

.... 1

- 34

T able 1.7. Major networkwide changes in sampling, analysis, and data reporting affecting samples collected January 2005 and later.

................................ ................................ ................. 1

- 35 Table 1.8. Chemical Speciation Network (CSN) site location, setting and region.

.............. 1

- 38 Table 1.9. Comparisons between collo cated IMPROVE and CSN sites for all data from 2005 through 2008. Species include organic carbon (OC), light absorbing carbon (LAC), ammonium sulfate (AS), ammonium nitrate (AN), soil, sea salt, PM 2.5 gravimetric fine mass (FM), and PM 2.5 reconstructed fine mass (RCFM). “OC unadj ” and “LAC unadj ” refer to comparisons between unadjusted CSN carbon data and IMPROVE carbon data; “OC adj ” and “LAC adj ” refer tocomparisons between adjusted CSN carbon and IMPROVE carbon data

. . ............................ 1

- 44 Table 2.1. Form of molecular species assumed in this report.

................................ ................ 2

- 3 Table 2.1.3. The negative multiplicative artifact (M) and the monthly positive additive organic artifact (A month ) used to adjust the CSN carbon concentrations for comparisons with IMPROVE. The units for the positive artifacts are  g m - 3 and M is unitless. Adjustments are listed as a function of sampler (columns).

................................ ................................ ................................ .... 2

- 6 Table 6.1. Results from long

- term (1989

– 2008) trend analyses for sulfate ion, total carbon (organic c arbon + light absorbing carbon), fine soil, gravimetric fine mass, coarse mass, and PM 10 . The minimum and maximum slope (μg m - 3 yr - 1 ) and trend (% yr - 1 ) are provided, along with the site corresponding to the maximum and minimum.

................................ ....................... 6

- 7

Table 6.2. Results from short

- term (2000

– 2008) trend analyses for sulfate ion, nitrate ion, total carbon (organic carbon + light absorbing carbon), fine soil, gravimetric fine mass, coarse mass, and PM 10 . The minimum and maximum slope (μg m - 3 yr - 1 ) and trend (% yr - 1 ) are provide d, along with the site corresponding to the maximum and minimum.

................................ ........... 6

- 11 Table 8.1. Design specifications of the IMPROVE and CSN samplers.

............................... 8

- 3 Table 8.2. The multiplicative artifact (1 + bOC) and the monthly positive organic artifact (a) used to relate the CSN and IMPROVE carbon concentrations. The units for the positive artifacts

are  g/m3 and 1 + bOC is unitless.

................................ ................................ ............................ 8

- 10xlv IMPROVE REPORT V Table 8.3. Summary of the percent seasonal variability and average difference of reconstructed versus gravimetric m ass.

................................ ................................ ..................... 8

- 19 Table 8.4a. Results of OLS regression analysis using equation 8.15 for the IMPROVE monitoring data.

................................ ................................ ................................ ......................... 8

- 21 Table 8.4b. Results of OLS regression analysis using equation 8.15 for the CSN/suburban monitoring data.

................................ ................................ ................................ ......................... 8

- 22

Table 8.4c. Results of OLS r egression analysis using equation 8.15 for the CSN/urban monitoring data.

................................ ................................ ................................ ......................... 8

- 22 Table 9.4.2. 2018 Reasonable progress goals compared to baseline visibility and uniform rate of progress, from the Tennessee and North Carolina regional haze state implementation plans.

....

................................ ................................ ................................ ................................ .................... 9

- 20 Table 9.4.3.1. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the worst 20% visibility days from WRAP regional analyses for Mesa Verde NP, CO (MEVE1) (from http://vista.cira.c olostate.edu/tss/Results/HazePlanning.aspx ).

...................... 9

- 22 Table 9.4.3.2. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the best 20% visibility days from WRAP regional analyses for Mesa Verde NP, CO (MEVE1) (from http://vi sta.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

...................... 9

- 23 Table 9.4.4.1. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the worst 20% visibility days from WRAP regional analyses for Hell’s Canyon Wilderness Area, OR/ID (HECA1) (from http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 28 Table 9.4.4.2. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the best 20% visibility days from WRAP regional analyses for H ell’s Canyon Wilderness Area, OR/ID (HECA1) (from http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

................................ ................. 9

- 29 Table 9.4.5.1. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the worst 20% visibility days fro m WRAP regional analyses for Agua Tibia Wilderness, CA (AGTI1) (from http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

....

................................ ................................ ................................ ................................ .................... 9

- 33 Table 9.4.5.2. Monitored, estimated, and projected 2018 visibility conditions and emissions changes for the best 20% visibility days from WRAP regional analyses for Agua Tibia Wilderness, CA (AGTI1) (from http://vista.cira.colostate.edu/tss/Results/HazePlanning.aspx ).

....

................................ ................................ ................................ ................................ .................... 9

- 34