RHR Archived Data

This page contains RHR Datasets delivered in previous years. The files do not contain updates that were implemented in subsequent years.

Regional Haze Rule Summary data through 1988 – 2021(January 2023)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
CSV file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
CSV file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. (zipped file)

Means for Impairment Metric:
CSV file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

Daily Impairment Values Including Patched Values:
CSV file with the daily IMPROVE species mass concentrations, calculated aerosol mass, light extinction values, and impairment parameters. Also included are the patched values where applicable. (zipped file)

2021 Summary plots for the 20% haziest and 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2020(February 2022)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
CSV file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Means for Impairment Metric:
CSV file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

2020 Summary plots for the 20% haziest and 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2019(December 2020)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
CSV file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Means for Impairment Metric:
CSV file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

2019 Summary plot for the 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2018(updated April 2020)

The 2018 Data were originally posted in 2019. The data posted in December 2019 are available, but the updated data are unchanged for most sites (see changes to the dataset described here).

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
CSV file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Means for Impairment Metric:
CSV file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

2018 Summary plots for the 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2017(posted December 2018)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
6.5 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
268 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. (zipped file 85 MB)

Means for Impairment Metric:
7.5 MB csv file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

Daily Impairment Values Including Patched Values:
413 MB csv file with the daily IMPROVE species mass concentrations, calculated aerosol mass, light extinction values, and impairment parameters. Also included are the patched values where applicable. (zipped file 122 MB)

2017 Summary plots for the 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2016(posted April 2018)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
6.2 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
255 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. (zipped file 81 MB)

Means for Impairment Metric:
7.1 MB csv file with the means of the 20% least impaired days (G10), middle 20% impairment days (G50) and 20% most impaired days (G90).

Daily Impairment Values Including Patched Values:
389 MB csv file with the daily IMPROVE species mass concentrations, calculated aerosol mass, light extinction values, and impairment parameters. Also included are the patched values where applicable. (zipped file 115 MB)

2016 Summary plots for the 20% most impaired days.

Regional Haze Rule Summary data through 1988 – 2015(posted December 2016)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
5.7 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
240 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. (zipped file 70 MB)

2015 Summary plots for the mean, 20% haziest, and 20% clearest days.

Regional Haze Rule Summary data through 1988 – 2014(posted November 2015)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
5 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
230 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. (zipped file 60 MB)

Regional Haze Rule Summary data through 1988 – 2013(posted July 2014)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
5 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Regional Haze Rule Summary data through 1988 – 2008 (posted November 2008)

Using the Second IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
3 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
150 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable.

Using the Original (Old) IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
3 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
115 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable.

Regional Haze Rule Summary data through 1988 – 2004 (posted March 2006)

Using the Second IMPROVE Algorithm:

NOTE: Data aggregations, calculated variables and patched values in the daily values data sets were generated using the procedures from the Guidance for Tracking Progress Under the Regional Haze Rule.

Baseline Haze Metrics for Best and Worst 20% Visibility Days:
226 KB xls file with the means of the best 20% visibility days (G10), worst 20% visibility days (G90), and all visibility days (G100)for the 5 year Regional Haze Rule baseline period (2000-2004). The baseline values were calculated following the RHR guidance documents using the new IMPROVE algorithm both with and without the State supplied substituted data.

Means for Best, Middle, and Worst 20% Visibility Days:
3 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
100 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable.

Using the Original (Old) IMPROVE Algorithm:

Means for Best, Middle, and Worst 20% Visibility Days:
3 MB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90).

Daily Values Including Patched Values:
73 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. NOTE: The following summary data used calculation procedures and/or data that has since been revised. These data are maintained for historical reason and should not be used for new analyses.

Summary data through 2003: (Updated 2/05)

Means for Best, Middle, and Worst 20% Visibility Days:
900 KB csv file with the means of the best 20% visibility days (G10), middle 20% visibility days (G50) and worst 20% visibility days (G90). These data aggregations were generated using the procedures from the Guidance for Tracking Progress Under the Regional Haze Rule.

Daily Values Including Patched Values:
28 MB csv file with the daily IMPROVE species mass concentrations and calculated aerosol mass and light extinction values. Also included are the patched values where applicable. Calculated variables and patched values were generated using the procedures from the Guidance for Tracking Progress Under the Regional Haze Rule.

Header Description:
18 KB excel file with descriptions of headers for the above two files. This includes parameter names as presented in the ASCII files and related parameter names in VIEWS, units, and calculation algorithms.

Summary data through 2002: (Updated 2/04)

Summary Data using Regional Haze Guidance Document (interim 2002) procedures

These data are used to generate some of the graphics presented in the Spatial Patterns, Composition, Trends, and Back Trajectories pages of the Annual Summary. The files here have data for the aerosol site (ASITE) and tracking progress site (TPSITE). Cases where the ASITE is different from the TPSITE are those where a Class I area designated as TPSITE uses aerosol data from a nearby Class I area designated as ASITE while using fRH from the TPSITE to calculate visibility metrics such as aerosol extinction and dv. Due to a possible bias in the pre 6/1996 nitrate data (see IMPROVE QA issues) the summary data are also reported with a constant particle NO3 value in metrics requiring particle NO3. These NO3 adjusted data are recommended for trend analysis prior to 2000, while the unadjusted data are recommended for use from 2000 on, or the period of Regional Haze Rule implementation.

Trends (5 Yr Rolling Avg) – Average Aerosol Components for 20% best, worst and middle visibility days (Update 4/03):
Five year rolling annual average concentrations of the total fine (PM2.5) and coarse (PM2.5-PM10) mass and major fine aerosol types for the 20% best (Group 10), worst (Group 90) and middle (Group 50) visibility days. The fractional contribution of the aerosol types to the reconstructed fine aerosol mass is also provided. These data are for all IMPROVE sites with data from 1988 – 2001. These data were used to construct the long term aerosol trends.

Data calculated using constant particle NO3 values can be obtained here. Datasets formatted for data processing can be found here and here (const. NO3).

These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (5 Yr Rolling Avg) – Average Light Extinction for 20% best, worst and middle visibility days (Update 4/03):
Five year rolling annual averages of reconstructed light extinction and the light scattering of the major aerosol types for the 20% best (Group 10), worst (Group 90) and middle (Group 50) visibility days. The fractional contribution of aerosol type light scattering to reconstructed extinction is also provided. These data are for all IMPROVE sites with data from 1988 – 2001. These data were used to construct the long term reconstructed light extinction trends.

Data calculated using constant particle NO3 values can be obtained here. Datasets formatted for data processing can be found here and here (const. NO3).

These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (1 Yr) – Average Aerosol Components for 20% best, worst and middle visibility days (Update 4/03):
Annual average concentrations of the total fine (PM2.5) and coarse (PM2.5-PM10) mass and major fine aerosol types for the 20% best (Group 10), worst (Group 90) and middle (Group 50) visibility days. The fractional contribution of the aerosol types to the reconstructed fine aerosol mass is also provided. These data are for all IMPROVE sites with data from 1988 – 2001. These data were used to construct the long term aerosol trends.

Data calculated using constant particle NO3 values can be obtained here. Datasets formatted for data processing can be found here and here (const. NO3).

These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (1 Yr) – Average Light Extinction for 20% best, worst and middle visibility days (Update 4/03):
Annual averages of reconstructed light extinction and the light scattering of the major aerosol types for the 20% best (Group 10), worst (Group 90) and middle (Group 50) visibility days. The fractional contribution of aerosol type light scattering to reconstructed extinction is also provided. These data are for all IMPROVE sites with data from 1988 – 2001. These data were used to construct the long term reconstructed light extinction trends.

Data calculated using constant particle NO3 values can be obtained here.

Datasets formatted for data processing can be found here and here (const. NO3). These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Summary Data using Regional Haze Guidance Document (draft September 2001) procedures
Trends (5 Yr Rolling Avg) – Average Aerosol Components for 20% best, worst and middle visibility days (Update 3/02):
Five year rolling annual average concentrations of the total fine (PM2.5) and coarse (PM2.5-PM10) mass and major fine aerosol types for the 20% best, worst and middle visibility days. The fractional contribution of the aerosol types to the reconstructed fine aerosol mass is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term aerosol trends.

A fixed length ASCII file can be obtained here. These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (5 Yr Rolling Avg) – Average Light Extinction for 20% best, worst and middle visibility days (Update 3/02):
Five year rolling annual averages of reconstructed light extinction and the light scattering of the major aerosol types for the 20% best, worst and middle visibility days. The fractional contribution of aerosol type light scattering to reconstructed extinction is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term reconstructed light extinction trends.

A fixed length ASCII file can be obtained here. These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (1 Yr) – Average Aerosol Components for 20% best, worst and middle visibility days (Update 3/02):
Annual average concentrations of the total fine (PM2.5) and coarse (PM2.5-PM10) mass and major fine aerosol types for the 20% best, worst and middle visibility days. The fractional contribution of the aerosol types to the reconstructed fine aerosol mass is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term aerosol trends.

A fixed length ASCII file can be obtained here. These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

Trends (1 Yr) – Average Light Extinction for 20% best, worst and middle visibility days (Update 3/02):
Annual averages of reconstructed light extinction and the light scattering of the major aerosol types for the 20% best, worst and middle visibility days. The fractional contribution of aerosol type light scattering to reconstructed extinction is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term reconstructed light extinction trends.

A fixed length ASCII file can be obtained here. These trends were generated using the procedures from the Draft Guidance for Tracking Progress Under the Regional Haze Rule.

20% Worst Visibility Days (Update 3/02):
Daily aerosol composite components and their contribution to light extinction for the 20% worst visibility days for each year from 1989 – 1999.

20% Best Visibility Days (Update 3/02):
Daily aerosol composite components and their contribution to light extinction for the 20% best visibility days for each year from 1989 – 1999.

Summary Data from

2000 IMPROVE Report
Annual and Seasonal Fine Mass Composition:
Annual and seasonal concentrations of the fine mass and major aerosol types aggregated over three years March 1996 – February 1999. The fractional contribution of each aerosol type to fine mass is also provided.

Annual and Seasonal Light Extinction Budget:
Annual and seasonal reconstructed light extinction and absolute and relative contribution from the major aerosol types during the three year period March 1996 – February 1999.

Monthly Fine Mass Composition:
Monthly summary data of reconstructed fine mass (PM2.5) and major fine aerosol species, (ammonium sulfate, ammonium nitrate, organics, light absorbing carbon, and fine soil. The data are aggregated over the 3 year period from March 1996 to February 1999. These data were used to create seasonal bar charts of the fine mass composition.

Monthly Light Extinction Budget:
Monthly summary data of reconstructed aerosol extinction and species specific extinction for the fine aerosol species, ammonium sulfate, ammonium nitrate, organics, light absorbing carbon, and fine soil combined with coarse mass. The data are aggregated over the 3 year period from March 1996 to February 1999. These data were used to create seasonal light extinction budget bar charts.

Light Extinction Diurnal Cycles:
Hourly light extinction data from IMPROVE transmissometer sites for each season of the year. In addition, the hourly F(rh), RH and temperature are provided. The aggregation was performed over each sites entire time series. These data were used to create bext diurnal cycles.

Annual Fine Mass Group 10, 50, 90:
Annual Group 10, 50, 90 average concentrations of the total fine (PM2.5) and coarse (PM2.5-PM10) mass and major fine aerosol types. The fractional contribution of the aerosol types to the reconstructed fine aerosol mass is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term trends aerosol trends. A fixed length ASCII file can be obtained here.

Annual Light Extinction Group 10, 50, 90:
Annual Group 10, 50, 90 averages of reconstructed light extinction and the light scattering of the major aerosol types. The fractional contribution of aerosol type light scattering to reconstructed extinction is also provided. These data are for all IMPROVE sites with data from 1988 – 1998. These data were used to construct the long term trends aerosol trends. A fixed length ASCII file can be obtained here.