Examining trends in synoptic-scale variability in wintertime CO2 readings at Mace Head, Ireland
Abstract
Continuous measurements of long-lived greenhouse gases at ground-based monitoring stations exhibit variations at multiple timescales. These include a well-established diurnal cycle and an annual pattern linked to seasonality, which generally exist on top of a long-term quasilinear trend. Other variations, related to localized surface fluxes or regional-scale atmospheric transport patterns, are observable at synoptic frequencies lasting from 1-2 days to several weeks. Extracting these latter components can reveal much about the intensity and geographical extent of anomalous events and provide useful information about long-term trends in trace species evolution, but this requires differentiating the signal into "background" and "non-background" components. Here, we make use of clean sector wind data to extract the Northern Hemisphere background CO2 signal at Mace Head (Ireland) for 1993 to 2020. We then apply a LOESS smoothing algorithm to daily CO2 readings at the site and investigate the timing of synoptic scale excursions from the baseline with regard to the prevalence of certain weather regimes during the winter months. Our goal is to identify relationships between the occurrence and strength of such regimes and the recorded CO2 signal in order to better understand long-term trends in sub-seasonal CO2 variability over Europe.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB066.0017R
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0469 Nitrogen cycling;
- BIOGEOSCIENCES;
- 0490 Trace gases;
- BIOGEOSCIENCES