Total Column Mixing Ratios of Carbon Dioxide, Methane and Carbon Monoxide from Toronto (UTSG)

The resulting scaled profile is then integrated to yield a total column-average dry-air mole fraction (more details in doi: 10.14291/tccon.ggg2014.documentation.R0/1221662). Quality filtering and post-processing methods are described by Mostafavi Pak et al., 2023 (doi: 10.5194/amt-16-1239-2023). In post-processing, an airmass dependent bias correction is applied, followed by an additive bias correction to bring all the EM27 instruments into agreement with a standard reference instrument, and finally a scaling factor is applied to correct to the WMO scale based on comparisons to AirCore measurements.

Because of their geographic proximity, the retrievals for the four Toronto sites, excluding the remote northern site at CARE (see doi for sites below), used common prior profiles based on model data interpolated to 43.63N, 79.38W. This was done to minimize the impacts of using different priors when analyzing gradients across the city of Toronto, but the CARE site is too far from the other sites for this to be reasonably applied.

Sites and data availability: University of Toronto St. George (UTSG; 43.661 N, 79.399 W) doi: 10.5683/SP3/WMQFDC. Environment and Climate Change Canada, Downsview (DOW; 43.781 N, 79.468 W) doi: 10.18164/f34f7044-0317-4774-a528-c60e84973f91.

University of Toronto Scarborough (UTSC; 43.784 N, 79.188 W) doi: 10.5683/SP3/80TERS. University of Toronto Mississauga (UTM; 43.549 N, 79.662 W) doi: 10.18164/f34f7044-0317-4774-a528-c60e84973f91. Centre for Atmospheric Research Experiments (CARE; 44.231 N, 79.783 W) doi: 10.18164/f34f7044-0317-4774-a528-c60e84973f91.