EQUATES Evaluation Data -- 01/01/2002 - 12/31/2019 12km CONUS

<h2>Data Summary</h2><p>CMAQv5.3.2 air quality and deposition estimates from the EPA’s Air Quality Time Series (EQUATES; <a href=www.epa.gov/cmaq/equates>www.epa.gov/cmaq</a>) project paired in space and time to measurement data for 01/01/2002 - 12/31/2019. </p>
<p>Measurements of ozone (O3), particulate matter with an effective aerodynamic diameter less than 2.5 µm (PM2.5), PM2.5 constituents (SO42-, NO3-, NH4+, OC, EC), and nitrogen oxides (NOX) and other gases are acquired from the USEPA's Air Quality System (AQS; https://www.epa.gov/aqs), which hosts data from networks maintained by various federal, state, and tribal agencies, including the Clean Air Status and Trends Network (CASTNET), the Interagency Monitoring of Protected Visual Environments (IMPROVE), the Chemical Speciation Network (CSN) and the National Air Pollution Surveillance Program (NAPS) in Canada. Weekly total deposition data are acquired from the National Atmospheric Deposition Program (NADP) National Trends Network (NTN). </p>
<p>Observational data from the different networks are reformatted and then paired in space and time with model values using the Atmospheric Model Evaluation Tool (AMET; Appel et al., 2011) version 1.4 (<a href=https://github.com/USEPA/AMET/tree/1.4>https://github.com/USEPA/AMET/tree/1.4</a>). Hourly O3 values are aggregated to Maximum Daily 8-hr averages (MDA8 O3), the metric used for determining attainment of EPA’s National Ambient Air Quality Standard for ozone. </p>
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<p>There are 7 .csv files provided for every month/year combination in the EQUATES timeseries. These are referred to as ‘sitecompare’ files.
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Files names (and approximate size per file); brief description:</p>
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<ul> <li>AQS_Daily_CMAQv532_12US1_{YEAR}.csv, (~30-50 MB); daily average PM2.5 and constituents from EPA’s AQS (including data from CSN and IMPROVE networks)</li>
<li>AQS_Daily_O3_CMAQv532_12US1_{YEAR}.csv, (~3-5 MB); MDA8 O3 and other daily ozone metrics from EPA’s AQS (including data from CASTNET)</li>
<li>AQS_Hourly_CMAQv532_12US1_{YEAR}.csv, (~500-900 MB); hourly PM2.5, ozone, NOX, other gaseous pollutants, and meteorological variables from EPA’s AQS (including data from CASTNET)</li>
<li>CASTNET_Daily_CMAQv532_12US1_{YEAR}.csv, (~400-500 KB); MDA8 O3 and other daily ozone metrics from CASTNET</li>
<li>NADP_CMAQv532_12US1_{YEAR}.csv, (~450-550 KB); weekly total precipitation, wet deposition, and wet concentration from NADP/NTN</li>
<li>NAPS_CMAQv532_12US1_{YEAR}.csv, (~40-50 MB); hourly PM2.5, ozone, NOX, other gaseous pollutant from NAPS (Canadian sites)</li>
<li>NAPS_Daily_CMAQv532_12US1_{YEAR}.csv, (~ 1MB or less); MDA8 O3 and other daily ozone metrics from NAPS (Canadian sites)</li></ul>

<p>See <a href=https://github.com/USEPA/CMAQ/blob/5.3.2/DOCS/Users_Guide/CMAQ_UG_ch08_analysis_tools.md#82-aggregating-and-transforming-model-species>Section 8.2 of the CMAQv5.3.2 User’s Guide</a> for information on how model output is matched to observational data using the combine, sitecmp, and sitecmp_dailyo3 Fortran utilities in the <a href=https://github.com/USEPA/CMAQ/blob/5.3.2/DOCS/Users_Guide/CMAQ_UG_ch08_analysis_tools.md>CMAQ GitHub code repository</a>.