Exceptional Events Analysis and Visualization Tools

The following tools can help with data screening and determining regulatory significance in support of exceptional events demonstration submissions.

Identify days potentially impacted by exceptional events

• Multi-year Tile Plot 
  Plots daily AQI values across multiple years. Each tile represents one day of the year and is color-coded based on the highest daily AQI value, helping identify days potentially impacted by exceptional events.

  

• Single-year Tile Plot
  Plots daily AQI values for a single year. Each tile represents one day of the year and is color-coded based on the highest daily AQI value, helping identify days potentially impacted by exceptional events.

  

• Concentration Map
  Maps daily concentrations over several days which can help identify areas potentially impacted by exceptional events.

  

• AirNowTech Navigator (requires account on AirNowTech)
  AirNowTech is a password-protected website for air quality data management, analysis, and decision support. It allows users to:
  • Access monitoring site data, information, and polling status
  • Analyze current and past air quality events and episodes
  • Submit and analyze air quality forecasts
     

Assess potential regulatory significance

• Exceptional Events Design Value Tool 
  This tool allows state, local, and tribal air monitoring agencies to determine the regulatory significance (i.e. whether excluding concentrations affected by exceptional events will affect attainment of the NAAQS) of ozone and PM_2.5 concentrations impacted by exceptional events by calculating the impact of excluding these concentrations on the design value, the statistic used to determine whether an ambient air quality monitoring site is meeting the NAAQS.
• Air Quality Statistics Report

Determine exceptional event tier category for your site(s) 

• PM_2.5 Tiering Tool 
  This tool displays daily PM_2.5 concentrations, along with tier levels based on the methodology described in the PM_2.5 Wildland Fire Exceptional Events Tiering Document.

Here are additional online resources and tools related to exceptional events data analysis.