Dataset includes reduced nitrogen (NHx) concentrations that were collected at Duke Forest, NC and Gainesville, FL using a CSN MetOne SuperSASS and IMPROVE PM sampler from May - October 2017. Using an acid impregnated filter in the CSN and IMPROVE samplers, NHx concentrations were compared to URG annular denuder measurements. Results are summarized in a report: Improving characterization of reduced nitrogen at IMPROVE and CSN monitoring sites (https://www.epa.gov/system/files/documents/2021-11/nhx_summary-report_final.pdf). Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

Publicly available data sets provided in the links were subsetted for the APNEP region and plotted for the report.

Publicly available data sets provided in the links were subsetted for the APNEP region and plotted for the report.

Data in Figure 1 are from publicly available databases including county-level ammonia (NH3) emissions from the US EPA National Emissions Inventory (https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data), ambient ammonium (NH4+) aerosol concentrations from the US EPA Clean Air Status and Trends Network (https://java.epa.gov/castnet/clearsession.do), and ambient NH3 concentrations from the National Atmospheric Deposition Program Ammonia Monitoring Network (AMoN) (http://nadp.slh.wisc.edu/data/AMoN/) Satellite observations of NH3 from the Infrared Atmospheric Sounding Instrument (IASI V2.2R) shown in Figure 2 are also publicly available (https://en.aeris-data.fr/metadata/?dc9dcce0-9324-451b-8d79-2d6df3094068). Diurnal profiles of ambient NH3 at different sites across the U.S. are summarized in Figure 3. Data from sites operated by EPA Office of Research and Development are attached as a spreadsheet with accompanying data dictionary. Greg Beachley (Beachley.gregory) is the contact for data from the Charleston, SC; Beltsville, MD and Bondville, IL sites. Katherine Benedict (Katherine.Benedict@colostate.edu) is the contact for data from the RMNP; Fort Collins, CO and Greeley, CO sites. This dataset is associated with the following publication: Puchalski, M., J. Walker, G. Beachley, M. Zondlo, K. Benedict, R. Grant, B. Schichtel, C. Rogers, A. Leytem, J. Rice, K. Morris, J. Schauer, and R. Wang. Need for Improved Monitoring of Spatial and Temporal Trends of Reduced Nitrogen. ENVIRONMENTAL MANAGEMENT. Springer-Verlag, New York, NY, USA, 0, (2019).

Data in Figure 1 are from publicly available databases including county-level ammonia (NH3) emissions from the US EPA National Emissions Inventory (https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-data), ambient ammonium (NH4+) aerosol concentrations from the US EPA Clean Air Status and Trends Network (https://java.epa.gov/castnet/clearsession.do), and ambient NH3 concentrations from the National Atmospheric Deposition Program Ammonia Monitoring Network (AMoN) (http://nadp.slh.wisc.edu/data/AMoN/) Satellite observations of NH3 from the Infrared Atmospheric Sounding Instrument (IASI V2.2R) shown in Figure 2 are also publicly available (https://en.aeris-data.fr/metadata/?dc9dcce0-9324-451b-8d79-2d6df3094068). Diurnal profiles of ambient NH3 at different sites across the U.S. are summarized in Figure 3. Data from sites operated by EPA Office of Research and Development are attached as a spreadsheet with accompanying data dictionary. Greg Beachley (Beachley.gregory) is the contact for data from the Charleston, SC; Beltsville, MD and Bondville, IL sites. Katherine Benedict (Katherine.Benedict@colostate.edu) is the contact for data from the RMNP; Fort Collins, CO and Greeley, CO sites. This dataset is associated with the following publication: Puchalski, M., J. Walker, G. Beachley, M. Zondlo, K. Benedict, R. Grant, B. Schichtel, C. Rogers, A. Leytem, J. Rice, K. Morris, J. Schauer, and R. Wang. Need for Improved Monitoring of Spatial and Temporal Trends of Reduced Nitrogen. ENVIRONMENTAL MANAGEMENT. Springer-Verlag, New York, NY, USA, 0, (2019).

Data presented in this manuscript are publicly available per the links provided. These include the US EPA National Emissions Inventory, US EPA Clean Air Status and Trends Network, National Atmospheric Deposition Ammonia Monitoring Network and National Atmospheric Deposition Program Total Deposition Maps. This dataset is associated with the following publication: Beachley, G., C. Rogers, T. Lavery, J. Walker, and M. Puchalski. Long-term trends in reactive N deposition in the U.S.. ENVIRONMENTAL MANAGEMENT. Springer-Verlag, New York, NY, USA, 0, (2019).

Data presented in this manuscript are publicly available per the links provided. These include the US EPA National Emissions Inventory, US EPA Clean Air Status and Trends Network, National Atmospheric Deposition Ammonia Monitoring Network and National Atmospheric Deposition Program Total Deposition Maps. This dataset is associated with the following publication: Beachley, G., C. Rogers, T. Lavery, J. Walker, and M. Puchalski. Long-term trends in reactive N deposition in the U.S.. ENVIRONMENTAL MANAGEMENT. Springer-Verlag, New York, NY, USA, 0, (2019).

This dataset contains statistical model (NH3_STAT) data. Global ammonia (NH3) emissions into the atmosphere are projected to increase in the coming years with the increased use of synthetic nitrogen fertilizers and cultivation of nitrogen-fixing crops. A statistical model (NH3_STAT) is developed for characterizing atmospheric NH3 emissions from agricultural soil sources, and compared to the performance of other global and regional NH3 models (e.g., EDGAR, MASAGE, MIX and U.S. EPA). The statistical model was developed by expressing a multiple linear regression equation between NH3 emission and the physicochemical variables. The model was evaluated for 2012 NH3 emissions. The results indicate that, in comparison to other data sets, the model provides a lower global NH3 estimate by 57%, (NH3_STAT: 13.9 Tg N yr-1; EDGAR: 33.0 Tg N yr-1). We also performed a region-based analysis (U.S., India, and China) using the NH3_STAT model. For the U.S., our model produces an estimate that is 143% higher in comparison to EPA. Meanwhile, the NH3_STAT model estimate for India shows NH3 emissions between -0.8 and 1.4 times lower when compared to other data sets. A lower estimate is also seen for China, where the model estimates NH3 emissions 0.4-5 times lower than other datasets. The difference in the global estimates is attributed to the lower estimates in major agricultural countries like China and India. The statistical model captures the spatial distribution of global NH3 emissions by utilizing a simplified approach compared to other readily available datasets. Moreover, the NH3_STAT model provides an opportunity to predict future NH3 emissions in a changing world.

Public data used for data harmonization. This dataset is associated with the following publication: Uhran, B., L. Windham-Myers, N. Bliss, A. Nahlik, E. Sundquist, and C. Stagg. Improved Wetland Soil Organic Carbon Stocks of the Conterminous U.S. Through Data Harmonization. Frontiers in Soil Science. Frontiers, Lausanne, SWITZERLAND, 1: 706701, (2021).