Articles | Volume 7, issue 6
Geosci. Model Dev., 7, 2557–2579, 2014

Special issue: The community version of the Weather Research and Forecasting...

Geosci. Model Dev., 7, 2557–2579, 2014

Development and technical paper 08 Nov 2014

Development and technical paper | 08 Nov 2014

Gaseous chemistry and aerosol mechanism developments for version 3.5.1 of the online regional model, WRF-Chem

S. Archer-Nicholls1, D. Lowe1, S. Utembe2, J. Allan1,3, R. A. Zaveri4, J. D. Fast4, Ø. Hodnebrog5,*, H. Denier van der Gon6, and G. McFiggans1 S. Archer-Nicholls et al.
  • 1Centre for Atmospheric Sciences, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester, UK
  • 2School of Earth Sciences, University of Melbourne, Victoria, Australia
  • 3National Centre of Atmospheric Science, University of Manchester, Manchester, UK
  • 4Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington, USA
  • 5Department of Geosciences, University of Oslo, Norway
  • 6Department of Climate, Air, and Sustainability, TNO, Utrecht, the Netherlands
  • *now at: Centre for International climate and Environmental Research-Oslo (CICERO), Oslo, Norway

Abstract. We have made a number of developments to the Weather, Research and Forecasting model coupled with Chemistry (WRF-Chem), with the aim of improving model prediction of trace atmospheric gas-phase chemical and aerosol composition, and of interactions between air quality and weather. A reduced form of the Common Reactive Intermediates gas-phase chemical mechanism (CRIv2-R5) has been added, using the Kinetic Pre-Processor (KPP) interface, to enable more explicit simulation of VOC degradation. N2O5 heterogeneous chemistry has been added to the existing sectional MOSAIC aerosol module, and coupled to both the CRIv2-R5 and existing CBM-Z gas-phase schemes. Modifications have also been made to the sea-spray aerosol emission representation, allowing the inclusion of primary organic material in sea-spray aerosol. We have worked on the European domain, with a particular focus on making the model suitable for the study of nighttime chemistry and oxidation by the nitrate radical in the UK atmosphere. Driven by appropriate emissions, wind fields and chemical boundary conditions, implementation of the different developments are illustrated, using a modified version of WRF-Chem 3.4.1, in order to demonstrate the impact that these changes have in the Northwest European domain. These developments are publicly available in WRF-Chem from version 3.5.1 onwards.