284d232c-1067-453f-9e4a-3f16de42b1b4 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 2025-07-23 ISO 19139 Geographic Information - Metadata - Implementation Specification 2007 102039 Esri 8.1.2 EnviroAtlas - Atmospheric Nitrogen and Sulfur Deposition by 12-digit HUC for the Conterminous United States (2017) U.S. Environmental Protection Agency (US EPA) originator U.S. EPA Office of Research and Development (ORD) - Center for Public Health and Environmental Assessment (CPHEA) Research Triangle Park, NC publisher tableDigital This EnviroAtlas dataset includes annual nitrogen and sulfur deposition within each 12-digit HUC subwatershed for the year 2017. Values are provided for total oxidized nitrogen (HNO3, NO, NO2, N2O5, NH3, HONO, PAN, organic nitrogen, and particulate NO3), oxidized nitrogen wet deposition, oxidized nitrogen dry deposition, total reduced nitrogen (NH3 and particulate NH4), reduced nitrogen dry deposition, reduced nitrogen wet deposition, total dry nitrogen deposition, total wet nitrogen deposition, total nitrogen deposition (wet+dry), total sulfur (SO2 + particulate SO4) dry deposition, total sulfur wet deposition, and total sulfur deposition. The dataset is based on output from the Community Multiscale Air Quality modeling system (CMAQ) run using the bidirectional flux option for the 12-km grid size for the US, Canada, and Mexico. The CMAQ output has been post-processed to adjust the wet deposition for errors in the location and amount of precipitation and for regional biases in the TNO3 (HNO3 + NO3), NHx (NH4 + NH3), and sulfate wet deposition. Model predicted values of dry deposition were not adjusted. 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 translating between nitrogen and sulfur emissions and ecological exposure. 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 as input to watershed models as part of Total Maximum Daily Loads (TMDL) calculations and to biogeochemical models as part of critical loads analyses. 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 12-digit HUCs Ecosystem Services EnviroAtlas Environment Environmental Atlas theme User 2022-01-11 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 textTable eng utf8 Microsoft Windows 10 Version 10.0 (Build 19042) ; Esri ArcGIS 12.9.0.32739 true -128.007244 -65.25485 22.868654 51.64959 2017-01-01T00:00:00 2017-12-31T00:00:00 This dataset can be joined to the EnviroAtlas feature class NHDPlusV2_WBDSnapshot_EnviroAtlas_CONUS using the field 'HUC_12.' File Geodatabase Table https://enviroatlas.epa.gov/download/CONUS_metrics_FGDB.zip download download https://enviroatlas.epa.gov/download/CONUS_metrics_CSV.zip download download https://www.epa.gov/enviroatlas/enviroatlas-data information information https://www.epa.gov/enviroatlas information information https://enviroatlas-epa.hub.arcgis.com/search?tags=EA-AMAD 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 Weather Research Forecast model, version 4.1.1 Weather Research Forecast model, version 4.1.1 2017 500m Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type 2017 500m Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type 2017-01-01 publication 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 data processed using CMAQ CALC_TMETRIC post-processor to create a gridded file containing annual total deposition values 2021-05-20T00:00:00 Resampled GeoTIFF rasters from 12km to 30m so they will align better with 12-digit HUC boundaries and produce more accurate zonal statistics. 2021-10-19T00:00:00 Used ArcGIS Zonal Statistics as Table with statistics type = Mean to reallocate 2017 gridded data to 12-digit HUCs. 2021-11-02T00:00:00 EPA's Air Quality Time Series (EQUATES) 2017 modeling platform EPA's Air Quality Time Series (EQUATES) 2017 modeling platform asNeeded 2025-07-30