A5038664784- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Atmospheric and Environmental Gas Dynamics
- Vehicle emissions and performance
- Catalytic Processes in Materials Science
- Climate variability and models
- Air Quality Monitoring and Forecasting
- Tropical and Extratropical Cyclones Research
- Wind and Air Flow Studies
- Gas Sensing Nanomaterials and Sensors
- Ocean Waves and Remote Sensing
- Analytical Chemistry and Sensors
- Meteorological Phenomena and Simulations
- Advanced Chemical Sensor Technologies
- Mercury impact and mitigation studies
- Industrial Gas Emission Control
- Hydrocarbon exploration and reservoir analysis
- Advanced Combustion Engine Technologies
- Geochemistry and Geologic Mapping
- Environmental Policies and Emissions
- Coal Properties and Utilization
- Wind Energy Research and Development
- Radioactivity and Radon Measurements
- Maritime Transport Emissions and Efficiency
The University of Melbourne
2014-2023
Environmental Protection Authority
2020
University of Bristol
2007-2017
University of Manchester
2011-2013
National Centre for Atmospheric Science
2011-2013
Imperial College London
2005-2007
University of Cambridge
2001-2005
Abstract. A photochemical trajectory model has been used to simulate the chemical evolution of air masses arriving at TORCH field campaign site in southern UK during late July and August 2003, a period which included widespread prolonged pollution episode. The incorporates speciated emissions 124 non-methane anthropogenic VOC three representative biogenic VOC, coupled with comprehensive description chemistry their degradation. representation gas/aerosol absorptive partitioning ca. 2000...
Abstract. Recently reported model-measurement discrepancies for the concentrations of HOx radical species (OH and HO2) in locations characterized by high emission rates isoprene have indicated possible deficiencies representation OH recycling formation mechanisms currently employed numerical models; particularly at low levels NOx. Using version 3.1 Master Chemical Mechanism (MCM v3.1) as a base mechanism, sensitivity system to number detailed mechanistic changes is examined wide range NOx...
The second NASA Earth Venture Mission, Geostationary Carbon Cycle Observatory (GeoCarb), will provide measurements of atmospheric carbon dioxide (CO2), methane (CH4), monoxide (CO), and solar-induced fluorescence (SIF) from Orbit (GEO). GeoCarb mission deliver daily maps column concentrations CO2, CH4, CO over the observed landmasses in Americas at a spatial resolution roughly 10 x km. Persistent CO, SIF contribute significantly to resolving emissions illuminating biotic processes urban...
Carbonyl oxides ("Criegee intermediates"), formed in the ozonolysis of alkenes, are key species tropospheric oxidation organic molecules and their decomposition provides a non-photolytic source OH atmosphere (Johnson Marston, Chem. Soc. Rev., 2008, 37, 699, Harrison et al., Sci. Total Environ., 2006, 360, 5, Gäb Nature, 1985, 316, 535, ). Recently it was shown that small Criegee intermediates, C.I.'s, react far more rapidly with SO2 than typically represented models, (Welz, Science, 2012,...
Abstract. We have made a number of developments to the Weather, Research and Forecasting model coupled with Chemistry (WRF-Chem), aim improving prediction trace atmospheric gas-phase chemical aerosol composition, interactions between air quality weather. A reduced form Common Reactive Intermediates mechanism (CRIv2-R5) has been added, using Kinetic Pre-Processor (KPP) interface, enable more explicit simulation VOC degradation. N2O5 heterogeneous chemistry added existing sectional MOSAIC...
The impact of including a more detailed VOC oxidation scheme (CRI v2-R5) with multi-generational approach for simulating tropospheric acetone is investigated using 3-D global model, STOCHEM-CRI. CRI v2-R5 mechanism contains photochemical production from monoterpenes which account 64% (46.8 Tg/yr) the sources in Both photolysis and by OH troposphere contributes equally (42%, each) dry deposition 16% atmospheric sinks acetone. life-time burden are found to be 18 days 3.5 Tg, respectively,...
Abstract. Following on from the companion study (Johnson et al., 2006), a photochemical trajectory model (PTM) has been used to simulate chemical composition of organic aerosol for selected events during 2003 TORCH (Tropospheric Organic Chemistry Experiment) field campaign. The PTM incorporates speciated emissions 124 non-methane anthropogenic volatile compounds (VOC) and three representative biogenic VOC, highly-detailed representation atmospheric degradation these emission primary (POA)...
Increasing the complexity of chemistry scheme in global transport model STOCHEM to STOCHEM-CRI (Utembe et al., 2010) leads an increase NOx as well ozone resulting higher NO3 production over forested regions and impacted by anthropogenic emission. Peak is located continents near emission sources. formed main reaction NO2 with O3, significant losses are due photolysis reactions NO VOCs. Isoprene important biogenic VOC, possibility HOx recycling via isoprene other mechanisms such RO2 HO2 has...
Abstract. We investigate the ability of column-integrated trace gas measurements from a geostationary satellite to constrain surface fluxes at regional scale. The proposed GEOCARB instrument measures CO2, CO and CH4 maximum resolution 3 km east–west × 2.7 north–south. Precisions are ppm for 10 ppb 18 CH4. Sampling frequency is flexible. Here we sample region location Shanghai every 2 daylight hours 6 days in June. test observing system by calculating posterior uncertainty covariance fluxes....
Abstract. Chemical modelling studies have been conducted over north-western Europe in summer conditions, showing that night-time dinitrogen pentoxide (N2O5) heterogeneous reactive uptake is important regionally modulating particulate nitrate and has a~modest influence on oxidative chemistry. Results from Weather Research Forecasting model with Chemistry (WRF-Chem) simulations, run a detailed volatile organic compound (VOC) gas-phase chemistry scheme the Model for Simulating Aerosol...
Abstract We document the implementation of Common Representative Intermediates Mechanism version 2, reduction 5 into United Kingdom Chemistry and Aerosol model (UKCA) 10.9. The mechanism is merged with stratospheric chemistry already used by StratTrop mechanism, as in UKCA UK Earth System Model, to create a new CRI‐Strat mechanism. simulates more comprehensive treatment non‐methane volatile organic compounds (NMVOCs) provides traceability Master Chemical Mechanism. In total, 233 species...
Abstract. Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH) using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing CH3I ionisation scheme. RHs studied <1, 11, 21, 27, 30 % and (0.07±0.01) (0.41±0.07) determined <1 RH respectively, showing strong water dependence. It has been possible estimate ratio rate coefficient for reaction Criegee...
Abstract. This paper describes a numerical experiment to test the ability of proposed geoCARB satellite estimate emissions trace gases (CO2, CH4 and CO) in polluted urban environment Shanghai. The meteorology over Shanghai is simulated with Weather Research Forecasting (WRF) model for 9-day period August 2010. includes water ice clouds. chemistry version WRF (WRF-Chem V3.6.1) used predict chemical composition, mass density number aerosol species. Spectra bands measured by are calculated,...
The global 3-D chemistry-transport model, STOCHEM-CRI (Utembe et al., 2010), has been used to simulate the distribution of organic hydroperoxides (ROOH) for both present day and pre-industrial scenarios. Globally, formation ROOH is solely from reaction between RO2 HO2, being more significant under NOx-limited conditions; here self cross reactions HO2 radicals dominate over their with NO. predominant loss processes are OH (95%) by photolysis (4.4%) a minor (<1%) deposition, in scenario....