Abstract

Short-lived pollutants in the troposphere, including carbon monoxide, volatile organic compounds, oxides of nitrogen, and particulate matter, have many impacts on air-quality, human health and climate, acting from regional to global scales. Exposure to fine particulate matter is linked with serious cardio-pulmonary health outcomes, causing an estimated 5.5 million premature deaths per year globally. Aerosol particles can be directly emitted from many anthropogenic and natural sources, or formed in the atmosphere through complex multiphase chemistry. Tropospheric aerosol also affects the radiative budget, both directly through scattering and absorbing radiation, and indirectly through influencing cloud properties. To fully simulate these processes, it is necessary to conduct online 3D simulations, whereby the chemical and aerosol model components are integrated at the same time as the physical components, enabling representation of feedbacks. Due to the spatial heterogeneity of short-lived species, and the complex interactions with clouds and other multiphase processes, it can be beneficial to compliment global simulations with nested high-resolution regional models.

This talk presents three applications to use and develop the regional, ‘online’, Weather Research and Forecasting model with Chemistry (WRF-Chem, https://ruc.noaa.gov/wrf/wrf-chem/) to tackle various scientific problems in different environments. The first looks at night-time chemistry over UK, in particular the NO3 radical, it’s dependency on N2O5 heterogeneous chemistry, and its importance for the nighttime oxidation budget. The second focuses on the radiative effects of biomass burning emissions in Brazil, using high-resolution nested domains to investigate aerosol-radiation-cloud interactions. Finally, we applied WRF -Chem to investigate the impacts of residential combustion emissions on air quality and health in China, and the local radiative effects of this high black-carbon source. Lessons learnt from these studies and future directions will be further discussed.