DF8359EB-C8E6-4FC1-BD1E-767745C886DE eng utf8 dataset dataset EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development - Center for Public Health and Environmental Assessment (CPHEA), EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact 2025-01-08 ISO 19139 Geographic Information - Metadata - Implementation Specification 2007 2 column 391 12000.000000 row 248 12000.000000 area true false -2292000.000000 -1644000.000000 -2292000.000000 1332000.000000 2400000.000000 1332000.000000 2400000.000000 -1644000.000000 center 0 EnviroAtlas - Particulate Matter Concentration (PM2.5) - Days over 35 micrograms per cubic meter in 2017 for the Conterminous United States 2021-12-16 publication 2021-12-16 revision tableDigital This raster GIS dataset includes the number of days in 2017 that the concentration of particulate matter with a diameter of 2.5 micrometers or smaller (PM2.5) predicted by the Community Multiscale Air Quality modeling system (CMAQ) exceeds a threshold value of 35 micrograms per cubic meter. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets). Air quality models are an important tool for providing complete spatial representation of atmospheric concentrations of pollutants across the U.S. The purpose of this data is to provide the information from the air quality model (CMAQ) on the resultant spatial variation in the exposure due to the complex emissions patterns and their transport and transformation. This dataset can be used to assess where human health and ecosystem impacts due to exposure to particulate may be more likely to occur. The overall goal of EnviroAtlas is to employ and develop the best available science to map indicators of ecosystem services production, demand, and drivers for the nation. completed EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development - Center for Public Health and Environmental Assessment (CPHEA), EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas publisher asNeeded Alabama Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas United States Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming place EPA Place Names 2015-01-31 publication Air Ecosystem Environment Exposure Modeling theme EPA GIS Keyword Thesaurus 2007-11-02 publication 020:072 theme Federal Program Inventory 2013-09-16 publication Air Ecosystem Services EnviroAtlas Environment Environmental Atlas Exposure Modeling theme User 2021-12-15 publication None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated. EPA Public Domain License licenseUnrestricted https://edg.epa.gov/EPA_Data_License.html unclassified https://project-open-data.github.io/schema/#accessLevel Additional information regarding security restrictions on handling the resource or metadata. grid eng utf8 Microsoft Windows 10 Version 10.0 (Build 18363) ; Esri ArcGIS 12.9.0.32739 true -128.4049 -64.237763 22.607417 51.93219 2017-01-01T00:00:00 2017-12-31T00:00:00 The CMAQ modeling system relies on first principles to the extent possible and the best available science underlies the modeling algorithms. Still, the chemistry and physics of the atmosphere are very complicated and there are uncertainties in the model representations that result in uncertainties in the predicted concentrations and deposition fluxes. There are also uncertainties in the model inputs including the emissions, meteorology, and land use. Emissions are the best available as part of the National Emissions Inventory (NEI), yet emission estimates are believed to be an important source of uncertainty. The data have been summarized based on HUCs but actual atmospheric concentrations will vary within the HUC. The number of days per year that the 24-hour average concentration of particulate matter with a diameter of 2.5 micrometers or smaller (PM2.5) exceeds 35 micrograms per cubic meter. physicalMeasurement 1 1 Band_1 131 0 Unified Code of Units of Measure d false false false false false File Geodatabase Raster Dataset https://edg.epa.gov/data/PUBLIC/ORD/ENVIROATLAS download download https://enviroatlas.epa.gov/arcgis/rest/services ESRI:ArcGIS offlineAccess https://www.epa.gov/enviroatlas/enviroatlas-data information information https://www.epa.gov/enviroatlas information information dataset Tests for integrity have not been performed. EPA National Geospatial Data Policy Features have been reviewed by U.S. EPA EnviroAtlas Project Managers for public release. true Features represented have not been tested for completeness EPA National Geospatial Data Policy Features have been reviewed by U.S. EPA EnviroAtlas Project Managers for public release. true 2017 WRF (Weather Research Forecast model) v4.1.1 runs completed 2020-04-29T00:00:00 2017 MCIP (Meteorology-Chemistry Input Processor) v5.0 runs completed 2020-04-30T00:00:00 2017 Environmental Policy Integrated Climate (EPIC) model fertilizer application amount and timing produced (http://www.cmascenter.org). 2020-07-27T00:00:00 2017 CMAQ (Community Multiscale Air Quality) v5.3.2 model run completed. 2021-05-18T00:00:00 2017 CMAQ model post-processed to number of days with 24 hour PM2.5 greater than threshold 2021-05-20T00:00:00 Use ArcGIS Pro Extract By Mask with NHDPlusV2_WBDSnapshot_EnviroAtlas_CONUS (EnviroAtlas 12-digit HUCs) as the mask to remove areas outside of the Conterminous United States and over the Great Lakes. Removing areas where the data is less reliable. 2021-12-09T00:00:00 asNeeded 2025-07-30