Environment and Climate Change Canada's (ECCC’s) air quality model, Global Environmental Multiscale – Model of Atmospheric Chemistry (GEM-MACH v2), was run at high spatial resolution to generate daily forecasts for the Air Quality Health Index (AQHI) at Pan Am sporting venue locations and for surface air quality measurement stations across the Greater Toronto Area. The model was run for a domain covering all of Southern Ontario at a spatial resolution of 2.5-km grid spacing. The model also included updated traffic pollutant emissions, generated before the Games by using a road link-based, traffic flow model. The GEM-MACH model generated daily forecasts on an hourly interval and forecasts were available at 6am local time each morning. Numerous chemical pollutants were predicted including ozone, nitrogen dioxide, carbon monoxide, sulfur dioxide, particulate matter, among others. The air quality forecasts were placed on several data servers for dissemination (ECCC Air Quality Model experimental website, Science and Technology ECPASS website, WISDOM health information website, MSC XM-Tools website, University of Toronto AirSensor website). The data in the archive is for the high resolution GEM-MACH v2 demonstration model and is not the operational air quality forecast disseminated by the Canadian Meteorological Centre. The demonstration forecast archived here has not been corrected using the post-processing UMOS tool, a statistical algorithm based on previous model/observations correlations for a location. A chemical objective analysis was also performed using the 2.5km GEM-MACH v2 model output and the surface observations within the model domain. The analysis is a fusion of the model and observations resulting in an improved model forecast surface map.

The World Meteorological Organization (WMO) Solid Precipitation Inter-Comparison Experiment (SPICE) officially began in the (Northern Hemisphere) Fall of 2012 with the objective of characterizing and providing guidance on the performance of automated systems for the in situ measurement of solid precipitation (Nitu et al., 2012). Environment and Climate Change Canada hosted three intercomparison sites as contributions to SPICE, two of which (Bratt’s Lake and Caribou Creek) are located in Saskatchewan. The Caribou Creek site is located in the southern Boreal forest, approximately 100 km North East of Prince Albert. The Bratt’s Lake site is located in the central prairies, approximately 30 km south of Regina. Each of the sites provides a different perspective for measuring precipitation. The Caribou Creek site exhibits a relatively longer and colder winter season but with lower wind speeds due to less exposure. The Bratt’s Lake site is drier and has a shorter accumulation season but experiences relatively high wind speeds due to exposure which makes accurate measurement of solid precipitation more challenging. Each of the Saskatchewan intercomparison sites measured accumulating precipitation with several gauge and wind shield configurations. Ancillary meteorological measurements of air temperature and wind speed at various heights were also made. This data set (October through April) begins in the fall of 2013 and continues through to the spring of 2017 and includes the two SPICE and two post-SPICE winters. The data consists of the core reference precipitation (WMO Double Fence Automated Reference and single Alter shielded gauges) and meteorological measurements (wind speed and air temperature). The precipitation and meteorology data were collected at a frequency of 1 minute, quality controlled and processed, and aggregated to 30 minute periods. Manual snow surveys were completed monthly (or bi-monthly) during the winter at the Caribou Creek site (with the exception of the 2015/2016 winter season). More information about this data set is included in the metadata.