Annual and five-year (5YA) average wet deposition maps for the non-sea-salt sulfate ion are available. The file formats include geodatabase files (*.gdb) compatible with geospatial software (e.g. ESRI ArcGIS) and KMZ files compatible with virtual globe software (e.g. Google Earth™). Maps can also be viewed online via Open Maps and the ArcGIS online viewer. Annual deposition from each site was screened for completeness using the following criteria: (1) precipitation amounts were recorded for >90% of the year and >60% of each quarter, and (2) sulfate concentrations were reported for >70% of the precipitation measured over the year and for >60% of each quarter. Five-year average wet deposition values are averaged annual deposition values with a completeness criterion >60% for the five-year period. Units for wet deposition fluxes are in kg of xSO4 per hectare per year (kg ha-1 y-1). Sources of measurement data and spatial interpolation method are described here: https://doi.org/10.18164/e8896575-1fb8-4e53-8acd-8579c3c055c2. Recommended citation: Environment and Climate Change Canada, [year published]. xSO4 Wet Deposition Maps. Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada. [URL/DOI], accessed [date]. Recommended acknowledgement: The author(s) acknowledge Environment and Climate Change Canada for the provision of Canada-U.S. wet deposition kriging maps accessed from the Government of Canada Open Government Portal at open.canada.ca, and the data providers referenced therein.

Annual and five-year (5YA) average wet deposition maps for the nitrate ion are available. The file formats include geodatabase files (*.gdb) compatible with geospatial software (e.g. ESRI ArcGIS) and KMZ files compatible with virtual globe software (e.g. Google Earth™). Maps can also be viewed online via Open Maps and the ArcGIS online viewer. Annual deposition from each site was screened for completeness using the following criteria: (1) precipitation amounts were recorded for >90% of the year and >60% of each quarter, and (2) nitrate concentrations were reported for >70% of the precipitation measured over the year and for >60% of each quarter. Five-year average wet deposition values are averaged annual deposition values with a completeness criterion >60% for the five-year period. Units for wet deposition fluxes are in kg of NO3 per hectare per year (kg ha-1 y-1). Sources of measurement data and spatial interpolation method are described here: https://doi.org/10.18164/e8896575-1fb8-4e53-8acd-8579c3c055c2. Recommended citation: Environment and Climate Change Canada, [year published]. NO3 Wet Deposition Maps. Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada. [URL/DOI], accessed [date]. Recommended acknowledgement: The author(s) acknowledge Environment and Climate Change Canada for the provision of Canada-U.S. wet deposition kriging maps accessed from the Government of Canada Open Government Portal at open.canada.ca, and the data providers referenced therein.

Patterns of wet deposition of the nitrate (NO3), non-sea-salt sulfate (xSO4) and ammonium (NH4) ions across areas of Canada and the United States are based on measurements of precipitation depth and ion concentrations in precipitation samples. xSO4 refers to the wet deposition of sulfate with the sea-salt sulfate contribution removed at coastal sites. These measurements were collected and quality controlled by their respective networks: in Canada, the federal Canadian Air and Precipitation Monitoring Network (CAPMoN) and provincial or territorial networks in Alberta, New Brunswick, the Northwest Territories, Nova Scotia, Ontario and Quebec. In the United States, wet deposition measurements were made by two coordinated networks: the National Atmospheric Deposition Program (NADP) / National Trends Network (NTN) and the NADP/Atmospheric Integrated Research Monitoring Network (AIRMoN). Only data from sites that were designated as regionally representative were used in the mapping. Wet deposition amounts were interpolated by ordinary kriging using ArcMap Geostatistical Analyst. The map is limited to the contiguous U.S. and southeastern or southern Canada because outside that region, the interpolation error exceeds 30% due to the larger distances between stations. Links to annual and five-year average maps are available in the associated resources.

Annual and five-year (5YA) average wet deposition maps for the ammonium ion are available. The file formats include geodatabase files (*.gdb) compatible with geospatial software (e.g. ESRI ArcGIS) and KMZ files compatible with virtual globe software (e.g. Google Earth™). Maps can also be viewed online via Open Maps and the ArcGIS online viewer. Annual deposition from each site was screened for completeness using the following criteria: (1) precipitation amounts were recorded for >90% of the year and >60% of each quarter, and (2) ammonium concentrations were reported for >70% of the precipitation measured over the year and for >60% of each quarter. Five-year average wet deposition values are averaged annual deposition values with a completeness criterion >60% for the five-year period. Units for wet deposition fluxes are in kg of NH4 per hectare per year (kg ha-1 y-1). Sources of measurement data and spatial interpolation method are described here: https://doi.org/10.18164/e8896575-1fb8-4e53-8acd-8579c3c055c2. Recommended citation: Environment and Climate Change Canada, [year published]. NH4 Wet Deposition Maps. Air Quality Research Division, Environment and Climate Change Canada, Toronto, Ontario, Canada. [URL/DOI], accessed [date]. Recommended acknowledgement: The author(s) acknowledge Environment and Climate Change Canada for the provision of Canada-U.S. wet deposition kriging maps accessed from the Government of Canada Open Government Portal at open.canada.ca, and the data providers referenced therein.

Air Monitoring Networks and Studies produce data that represent a wide variety of observations and measurements. Multiple data types (also called collections) can be produced by a single network and data collections can have contributions from multiple networks. The data are organised as follows: 1. Atmospheric Gases, 2. Atmospheric Particles, 3. Atmospheric Precipitation Chemistry, 4. Combined Atmospheric Gases and Particles 5. Special Studies of Atmospheric Gases, Particles and Precipitation Chemistry Networks and Studies contributing to the Canadian National Atmospheric Chemistry Database and Analysis system (NAtChem) are from Canadian federal and provincial networks (past and present) and also include U.S. historical networks (these data are not available elsewhere). Information about these contributing networks, for each of these collection and product groups, can be found in each network's description documentation.

Air emissions from oil sands development can come from a number of sources including industrial smokestacks, tailings ponds, transportation, and dust from mining operations. Air quality monitoring under the Joint Canada-Alberta Implementation Plan for the Oil Sands is designed to determine the contribution of emissions from oil sands activities to local and regional air quality and atmospheric deposition both now and in the future. Deposition data include: - Passive Sampling of PACs deployed for two month periods across a network of 17 sites - Active sampling of PACs at three sites to inform the amount of dry deposition - Particulate metals (24 hour integrated samples following the one in six day National Air Pollution Surveillance (NAPS) cycle)

Air emissions from oil sands development can come from a number of sources including industrial smokestacks, tailings ponds, transportation, and dust from mining operations. Air quality monitoring under the Joint Canada-Alberta Implementation Plan for the Oil Sands is designed to determine the contribution of emissions from oil sands activities to local and regional air quality and atmospheric deposition both now and in the future. Ambient air quality data include: - Filter Pack (24-hour integrated concentrations of particle-bound SO2-4, NO-3, Cl-, NH+4, Ca2+, Mg2+, Na+, K+ and gaseous SO2 and HNO3 collected daily by the Canadian Air and Precipitation Monitoring Network) - Total Gaseous Mercury (hourly mixing ratios measured by the Canadian Air and Precipitation Monitoring Network and Prairie and Northern Region) - Atmospheric speciated mercury (Hg) (2-hour average concentrations of gaseous elemental Hg (GEM), reactive gaseous Hg (RGM), and Hg on PM2.5 (total particulate Hg - TPM) - Comprehensive set of measurements collected from an aircraft (various time resolutions) covering an area of 140,000 km2 over the oil sands region - Comprehensive set of measurements collected from the Fort McKay Oski-ôtin monitoring site - Ozone (hourly mixing ratios measured by the Canadian Air and Precipitation Monitoring Network) - Ozone Vertical Profiles (ozone mixing ratios as a function of height) measured by the Canadian Ozone Sonde Network - Aerosol Optical Depth (measure of the degree to which the presence of aerosols in the atmosphere prevents the transmission of light, from the ground to the top of the atmosphere) measured as part of the AErosol RObotic CANadian (AEROCAN) network - Satellite overpass data have a relatively high spatial resolution over the Oil Sands region to produce images and geo-referenced data of nitrogen dioxide (NO2) and sulphur dioxide (SO2) “vertical column density” (which correlates with surface concentration)