Comprehensive analysis of annual 2005/2008 simulation of WRF/CMAQ over southeast of England

Nutthida Kitwiroon, Sean Beevers

Research output: Chapter in Book/Report/Conference proceedingOther chapter contributionpeer-review

Abstract

A comprehensive evaluation was conducted on annual 2005 WRF/CMAQ simulations over the southeast of England to identify the cause of model deficiencies and to determine if the model is suitable for policy applications. The model performance was characterised through operational, dynamic and diagnostic evaluations. For operational evaluations, the model results, downscaled from a horizontal grid resolution of 81km to 3km, were compared against the observations from 120 air quality monitoring sites measuring NO2 and O3 concentrations across the southeast of England. The predicted surface and vertical profiles of temperature, relative humidity and wind components were also evaluated, as was the predicted atmospheric pressure at mean sea level, which was compared with the synoptic scale charts. Demonstration of a number of model diagnostics was made possible through the use of 'Openair' (http://www.openair-project.org/), AMET (http://www.cmascenter.org) and through development of R scripts. These included time series plots, scatter plots, diurnal error plots, Taylor diagrams and statistical measures. The performance of WRF/CMAQ for 2005 showed that the model was able to capture seasonal trends, the magnitude of the observed meteorology, NO2 and O3, and the partitioning of oxidant (NO2+O3). The analysis presented indicates that overall CMAQ represents O3 concentrations well, although WRF over predicts wind speeds during the night and this has an impact on NO2 and O3 concentrations during this time. The dynamic evaluation showed that the model responds to changes in emissions of NOX and HC's and that these agree well with other results in the literature. Further sensitivity analyses between 2005 (typical UK weather) and 2008 (wet year) showed that the model is able to represent air pollution concentrations across a wide range of UK weather conditions. However possible areas for model improvement are also discussed. The diagnostic evaluation showed an indication of underprediction of local sources of the oxidant. Finally, the statistical measures presented here indicate that the WRF/CMAQ model is acceptable for policy applications in the UK.

Original languageEnglish
Title of host publicationHARMO 2010 - Proceedings of the 13th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes
PublisherARIA Technologies
Pages60-64
Number of pages5
ISBN (Electronic)9782868150622
Publication statusPublished - 2010
Event13th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2010 - Paris, France
Duration: 1 Jun 20104 Jun 2010

Conference

Conference13th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2010
Country/TerritoryFrance
CityParis
Period1/06/20104/06/2010

Keywords

  • CMAQ
  • Model evaluation
  • Model performance
  • Photochemical model
  • WRF

Fingerprint

Dive into the research topics of 'Comprehensive analysis of annual 2005/2008 simulation of WRF/CMAQ over southeast of England'. Together they form a unique fingerprint.

Cite this