Data Access

Data access

Data from the IMPROVE network are processed at AQRC and then sent quarterly to CIRA—the Cooperative Institute for Research in the Atmosphere—at Colorado State University in Fort Collins.

CIRA staff compile and format the data, then upload it to their FED website at

This extensive site serves as a portal for the general public and research community to access tools, resources and a vast network of data related to air quality, including ground-based measurements from dozens of monitoring networks, air quality monitoring results and NASA satellite data.

To access IMPROVE data on the FED website, follow the steps below.

Go to:

To download data, click on the Database Query Wizard, near the bottom of the FED homepage. You will see the heart of the Query Wizard, with a series of tabs, as follows:

  • Reports - Choose "Raw Data" to gain access to the IMPROVE data
  • Datasets - Choose "IMPROVE Aerosol" to get the data submitted by UC Davis. 
  • Sites - Select one or many sites, as you wish
  • Parameters - Here you will see both raw data and derived parameters. Choose the data that you would like to download.
  • Dates - Choose as you wish.
  • Aggregations - This tab allows you to filter by flags. As a simple approach, use the default (non-aggregated) and then filter once you have the data in hand.
  • Fields - Here you can choose to receive uncertainties, MDLs, etc. It is usually helpful to download the parameter occurrence code (POC). Primary data have POC=1 and collocated data have POC=2, so you will be able to distinguish between them.
  • Options - This tab allows you to choose your output. There are many choices, so here are a few tips:

    Output Medium – "Browser" will display the data on your screen, which is fine if you just want to glance at the data. But to make the data available for analysis choose "Excel" or "Text File," which will provide data that can be imported by other applications, including Excel.

    File Options – Choose to generate one file or multiple files.

    Column Format – Comma delimited works well. Use the default values for Row Format, Headers & Titles, String Quotes, Missing Values and Display Results.

    Content Options – If you have already reviewed the metadata and just want a clean data file, choose Data Only.

    Date Format – Choose what you like

When you have made all your choices, click "Submit" and a new window will appear at the bottom of the screen with a hyperlink to your data file. Click on the hyperlink and you'll get yet another new window containing a file that you can save to your hard drive, import into other applications, or whatever you like.