Raw Baseline Concentrations and Environmental Controls on Background CO2 and CH4 for Sites Across Canada
Abstract
Concentrations of gases in the lower atmosphere are controlled by spatially and temporally heterogeneous factors such as air temperature, biological activity and degree of industrial development. Seeing as how baseline concentrations are often required for studies of environmental change, we need a better understanding of the spatiotemporal controls on baseline atmospheric gas concentrations. In this study we collected >2.5M CO2 and CH4 concentration measurements across Canada over the course of two years and multiple seasons, by driving laser-based spectrometers in excess of 100,000 linear km. Geo-located concentration data were acquired at a frequency of 1 Hz and from an approximate height of 1.5 m. A signal processing algorithm was used to remove short-term plume features that were related to local industrial activity, so as to derive background concentrations that were more generally representative of natural landscape variation. We assessed relationships between background concentrations and environmental factors for each province, as well as areas with and without a high degree of oil and gas production. We also compared concentration signatures between winter and summer for some provinces, and were additionally able to provide a full season-by-season comparison for the province of Saskatchewan. Results suggest that temperature is the primary spatiotemporal control on CO2 and CH4 background concentrations, suggesting that the biosphere is the dominant regulator of concentrations near the ground surface. Local wind speeds and atmospheric pooling were comparatively less useful predictors of landscape CO2 and CH4 variation. These results will facilitate improved CO2 and CH4 baseline data estimates for environmental studies of many types in non-urban environments.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A31I0170F
- Keywords:
-
- 0322 Constituent sources and sinks;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0345 Pollution: urban and regional;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0478 Pollution: urban;
- regional and global;
- BIOGEOSCIENCES