AppalAIR

NOAA-ESRL Aerosol Measurements

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Raw Data

PLEASE REFER TO THE DATA USAGE POLICY BEFORE DOWNLOADING DATA.

Hourly, Daily and Monthly - Averaged Raw Data from 2009 to present is available on the NOAA-ESRL FTP Server.

The file-naming convention is as follows:

  • "a_" - Aerosol Data including Number Concentration, Scattering and Absorption.
  • "la_" - Aerosol Absorption Data Only.

After the underscore, you are given 3 options:

  • "_H" - Hourly Averaged data.
  • "_D" - Daily Averaged Data.
  • "_M" - Monthly Averaged Data.

The next 2 characters represent the 2-digit year. 

For Example: "a_H14.app" refers to the file containing hourly-averaged aerosol data for the 2014 year. Each file is a comma-delimited file and the date format is "YMD" (Year, Month, Day). 

 The format for the data in each file can be found on the NOAA-ESRL website .

See graphs on the NOAA website for the various Appalachian State University data streams. 

Processed - Quality Assured Data

Quality-assured data is made available in January for the previous year. For example, the data from 2014 is made available in January 2015. 

Please review the EBAS Data format .pdf file attached at the bottom of this page for questions regarding file format. 

Access the quality-assured data. 

The files containing fixed-width fields are easily opened in a common text editor such as Notepad. 

Instrument Model Information

  • Particle Soot Absorption Photometer (PSAP) - Radian Research #0046
  • Continuous Light Absorption Photometer (CLAP) - NOAA - #10.016
  • Condensation Nuclei Counter (CNC) - TSI 3760
  • Reference Nephelometer - TSI 3563
  • Wet Nephelometer  - TSI 3563

Ancillary Information

  1. Aerosol number density (particles/cm3) are measured by the TSI 3760
  2. Aerosol light absorption at 467nm, 530nm, and 660nm are measured by PSAP and at near-identical wavelengths by CLAP. Values are corrected to 450,550, and 700nm to align with scattering wavelengths of nephelometers
  3. Aerosol volume scattering and hemispheric backscattering coeffcients at 450nm, 550nm, and 700nm are measured at low relative humidities (RH>40%) by reference nephelometer
  4. Scattering , backscattering, and absorption at 450nm, 550nm, and 700nm are used to calculate aerosol intensive properties at low RH, including single-scattering albedo, hemispheric backscatter fraction, and scattering and absorption Angstrom exponents. The scattering and absorption data (items 2 and 3) can be requested for sub-1 micron aerosol size cut (PM1) or sub-10 micron aerosol size cut (PM10). Aerosol number density is only available for PM10.

Learn more about EBAS data format: