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AirData

Frequent Questions


I used to be able to get emissions data from the AirData website, but the site has changed. Where can I find that information now?

At this time, the best sources for emissions data are:

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I used to be able to generate nonattainment area maps on the AirData website, but the site has changed. Where can I get that information now?

At this time, the best source for nonattainment area maps is the EPA Greenbook Website.

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What is an exceptional event?

Exceptional Events are unusual or naturally occurring events that can affect air quality but are not reasonably controllable using techniques that tribal, state or local air agencies may implement in order to attain and maintain the National Ambient Air Quality Standards. For more information, see http://www.epa.gov/ttn/analysis/exevents.htm.

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Does the exclude exceptional events option exclude only EPA regionally-concurred exceptional events or all flagged events?

Choosing the “Exclude exceptional events data” option excludes all flagged exceptional events, regardless of concurrence.  Longer answer – States can flag data that may have been influenced by an exceptional event (e.g. high winds, wildfire).  As a user of AirData, you can choose to exclude these flagged data.  This option is available in the Air Quality Statistics Report and Monitor Values Report.  In the Air Quality Statistics Report, there is not a way to tell which, if any, statistics are affected by including/excluding exceptional events.  However, in the Monitor Values Report, there is a column that indicates whether there were any flagged data ('NONE'), whether flagged data were included ('INCLUDED') or excluded ('EXCLUDED').

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In the CSV files, are the exceptional events data indicated?

In the Air Quality Statistics Report, there is not a way to tell which, if any, statistics are affected by including/excluding exceptional events. However, in the Monitor Values Report, there is a column that indicates whether there were any flagged data ('NONE'), whether flagged data were included ('INCLUDED') or excluded ('EXCLUDED'). This field is in the CSV file also.

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How do the reports handle co-located PM2.5 monitors?

Each site-poc is treated as a separate monitor. To see an example of this, you can use the Concentration Plot tool for PM2.5.

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Does a PM2.5 query pull only data from monitors with a parameter code of 88101 or does it include others such as 88501?

Reports providing annual summary statistics the Air Quality Statistics Report and Monitor Values Report use only PM2.5 data reported as parameter code 88101 (PM2.5 LOCAL CONDITIONS). Reports and visualization tools providing AQI data use both 88101 and 88502 (ACCEPTABLE PM2.5 AQI & SPECIATION MASS). This methodology is consistent with the AQI and how standard AQS reports are generated. The Concentration Plot also pulls both 88101 and 88502, and the data for each parameter are plotted separately.

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Do the AQI calculations include Non-FEM/FRM continuous PM2.5 data?

Yes, PM2.5 data reported as parameter code 88101 (PM2.5 LOCAL CONDITIONS) and 88502 (ACCEPTABLE PM2.5 AQI & SPECIATION MASS) are used in the AQI summaries on AirData.

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If there's more than one monitor in a county, does the tile plot take the max AQI value among all the monitors in the county?

Yes. AQI displays/reports always use the maximum daily AQI value in the geographic region represented.

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Is it possible to query multiple years?

Not at this time. When the raw data query tool is added in the spring of 2012, it will provide that capability.

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Do you plan to make hourly data available through this site?

Yes. Raw data will be available with the new query tool on the Download Data section of the site in the spring of 2012.

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Can you get design values from AirData?

At this time, design values are not available from the AQS Data Mart. We will discuss what it would take to add them and to develop a design value report.

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Do you have plans to include air toxics data?

Yes. Currently, you can access daily and annual summary air toxics data from the NATTS monitoring sites using that layer in the Interactive Map. In the spring of 2012, we plan to add two tools that will provide better access to air toxics data. First, we plan to add a monitor-level annual summary HAP report to the Reports section. Second, we plan to add a raw data query tool to the Download Data section.

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What is the AQS Data Mart?

The AQS Data Mart is a database containing all of the information from the AQS system. The AQS Data Mart was built as a storehouse of air quality information that allows users to make queries of unlimited quantities of data while not affecting the primary AQS database. For more information, see the AQS Data Mart page.

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Do all AQI plots use the most current AQI breakpoints - regardless of what year you request?

Yes. Every AQI summary (report, graph, etc.) from AirData is based on the current AQI breakpoints regardless of year. Keep in mind, the current AQI 100 level for PM2.5 is 40 micrograms per cubic meter. See 40 CFR Part 58, Appendix G for details.

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What is the lag between the data being posted on AQS and it being used in AirData?

One to two days. The AQS Data Mart is updated each week night with data from AQS.

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Are the chemical speciation data parameters available from AirData?

Currently, you can access daily and annual summary chemical speciation data from the CSN monitoring sites using that layer in the Interactive Map. In the spring of 2012, we plan to add the raw data query tool which will provide access to the raw data.

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How do AirData and AirNow differ?

AirData provides monitoring data from AQS which can date back to 1980 depending on the pollutant, so you can do retrospective analyses with a number of pollutants. AirNow reports real-time and forecast air quality data with respect to the Air Quality Index, mostly based on ozone and PM2.5 concentrations. While there is some archive data available on the AirNow website, its primary purpose is to report what’s happening now and what is forecast to happen tomorrow.

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