Marked long-term decline in ambient CO mixing ratio in SE England, 1997–2014: evidence of policy success in improving air quality

Abstract : Atmospheric CO at Egham in SE England has shown a marked and progressive decline since 1997, following adoption of strict controls on emissions. The Egham site is uniquely positioned to allow both assessment and comparison of ‘clean Atlantic background’ air and CO-enriched air downwind from the London conurbation. The decline is strongest (approximately 50 ppb per year) in the 1997–2003 period but continues post 2003. A ‘local CO increment’ can be identified as the residual after subtraction of contemporary background Atlantic CO mixing ratios from measured values at Egham. This increment, which is primarily from regional sources (during anticyclonic or northerly winds) or from the European continent (with easterly air mass origins), has significant seasonality, but overall has declined steadily since 1997. On many days of the year CO measured at Egham is now not far above Atlantic background levels measured at Mace Head (Ireland). The results are consistent with MOPITT satellite observations and ‘bottom-up’ inventory results. Comparison with urban and regional background CO mixing ratios in Hong Kong demonstrates the importance of regional, as opposed to local reduction of CO emission. The Egham record implies that controls on emissions subsequent to legislation have been extremely successful in the UK.
Complete list of metadatas

Cited literature [28 references]  Display  Hide  Download

https://hal.sorbonne-universite.fr/hal-01321421
Contributor : Gilles d'Eggis <>
Submitted on : Wednesday, May 25, 2016 - 3:49:16 PM
Last modification on : Wednesday, July 10, 2019 - 7:04:03 PM
Long-term archiving on : Friday, August 26, 2016 - 10:57:59 AM

File

srep25661.pdf
Publication funded by an institution

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Citation

D. Lowry, M. E. Lanoisellé, R. E. Fisher, M. Martin, C. M. R. Fowler, et al.. Marked long-term decline in ambient CO mixing ratio in SE England, 1997–2014: evidence of policy success in improving air quality. Scientific Reports, Nature Publishing Group, 2016, 6, pp.25661. ⟨10.1038/srep25661⟩. ⟨hal-01321421⟩

Share

Metrics

Record views

1329

Files downloads

177