Bill’s group currently comprises two Postdoctoral Research Fellows (Dr Mike Newland and Dr Leigh Crilley), alongside a number of PhD students (see above) and MSc / project students. We contribute to the Air Pollution and Atmospheric Chemistry theme of the Environmental Health Sciences group at Birmingham.
Our work is supported by funding from RCUK (16 funded grants, 12 as lead PI, totalling >£3m), EU sources, the DFG, the Royal Society, the Royal Society of Chemistry and the Nuffield Foundation.
Atmospheric Chemistry :
Measurement and interpretation of ozone production in the atmospheric boundary layer
Sources and sinks for atmospheric oxidants: Impacts upon urban air quality and tropospheric composition
The atmospheric chemistry of halogen species, in particular iodine chemistry in the marine boundary layer
Measurement of Ozone Production Rates
Ozone is a critical air pollutant, harmful to human health, crops and vegetation, an important atmospheric reactant (precursor to the key radical oxidant OH), and a significant greenhouse gas. Understanding atmospheric ozone levels is therefore a key goal for atmospheric chemists, underpinning effective air quality policy measures. As ozone is a secondary pollutant, formed in the atmosphere from the complex processing of NOx and VOCs, predicting ozone levels is still a challenge for atmospheric models. We are developing an alternative approach to this problem, to directly measure the local chemical ozone production rate, as a complementary approach to model (and other observational) tools, and have made preliminary measurements in the UK and India (see news article). This work is funded by NERC and the Royal Society.
Alkene Ozonolysis: Radical Production and Criegee Chemistry
The gas-phase reaction between ozone and alkenes produces a range of products, including radical species such as OH, which are known to contribute to atmospheric processing, and newly detected species – stabilised criegee intermediates or SCIs – which may also drive atmospheric oxidation, for example converting SO2 to sulphate aerosol, affecting air quality and climate. In a series of projects, funded by NERC and the EU, we have investigated the radical and SCI production from the ozonolysis of a range of alkenes of biogenic and anthropogenic origin, and are now exploring their role as atmospheric oxidants for SO2 and NOx. We use the European Photoreactor (EUPHORE) large simulation chamber facility in Valencia, Spain, as our primary experimental tool, and interpret the data obtained using the MCM atmospheric model. This work is performed in collaboration with Andrew Rickard & Mat Evans (York), Luc Vereecken (MPI Mainz) and Marie Camredon (Paris / LISA).
Point Measurements of Iodine and Bromine in the Marine Boundary Layer
Iodine compounds released from the ocean cause a range of chemical effects in the marine atmosphere - they can influence atmospheric oxidant levels, participate in catalytic ozone destruction cycles, and potentially lead to the formation of new atmospheric particles, which may influence cloud formation and hence weather and climate. These natural processes are known to be important in certain coastal regions, but their significance over the open ocean, and hence overall global impact, is uncertain. We have developed a new instrument to measure halogen atoms, using the technique of Resonance Fluorescence, and applied this to measure iodine levels in the North Atlantic, in collaboration with Dwayne Heard (Leeds), and to perform simulation chamber studies of iodine chemistry in collaboration with Cornelius Zetzsch (Bayreuth) and Uli Platt (Heidelberg).
Over 50 international peer-reviewed journal articles (h-index = 23 [Web of Science]) and 8 chapters / contributions to edited works.
L.R. Crilley, W.J. Bloss et al. (2015) Sources and Contributions of Wood Smoke During Winter in London: Assessing Local and Regional Influences. Atmos. Chem. Phys., in press, 2015
M.J. Newland, A.R. Rickard, M.S. Alam, L. Vereecken, A. Muñoz, M. Ródenas & W.J. Bloss (2015) Kinetics of stabilised Criegee intermediates derived from alkene ozonolysis: reactions with SO2, H2O and decomposition under boundary layer conditions. Phys. Chem. Chem. Phys., 17, 4076-4088.
J. Zhong, X.-M. Cai & W. J. Bloss (2014) Modelling segregation effects of heterogeneous emissions on ozone levels in idealised urban street canyons: using photochemical box models. Environ. Polln., 188, 132-143
M.S. Alam, A. R. Rickard, M. Camredon, K. P. Wyche, T. Carr, K. E. Hornsby, P. S. Monks & W. J. Bloss (2013) Radical Product Yields from the Ozonolysis of Short Chain Alkenes under Atmospheric Boundary Layer Conditions. J. Phys. Chem. A, 117, 12468-12483
B. Ouyang, M. W. McLeod, R. L. Jones & W. J. Bloss (2013) NO3 radical production from the reaction between the Criegee intermediate CH2OO and NO2, Phys. Chem. Chem. Phys. 15, 17070-17075
R. Sommariva, W.J. Bloss & R. von Glasow (2012) Uncertainties in Gas-Phase Iodine Chemistry, Atmos. Environ. 57, 219-232.
M. S. Alam, M. Camredon, A. R. Rickard, T. Carr, K. P. Wyche, K. Hornsby, P. S. Monks and W. J. Bloss (2011) Total Radical Yields from Tropospheric Ethene Ozonolysis, Phys. Chem. Chem. Phys., 13, 11002-11015.
W.J. Bloss, M. Camredon, J. D. Lee, D. E. Heard, J. M. C. Plane, A. Saiz-Lopez, S. J.-B. Bauguitte, R. A. Salmon, and A. E. Jones (2010) Coupling of HOx, NOx and halogen chemistry in the Antarctic boundary layer, Atmos. Chem. Phys., 10, 10187-10209.
A. K. Mollner, L. Feng, M. K. Sprague, M. Okumura, D. B. Milligan, W. J. Bloss, S. P. Sander, P. T. Martien, R. A. Harley, A. B. McCoy and W.P. Carter (2010) Rate of gas phase association of hydroxyl radical and nitrogen dioxide, Science, 330, 646-649.
M. Camredon, J. F. Hamilton, M. S. Alam, K. P. Wyche, T. Carr, I. R. White, P. S. Monks, A. R. Rickard, and W. J. Bloss (2010) Distribution of gaseous and particulate organic composition during dark α-pinene ozonolysis, Atmos. Chem. Phys. 10, 2893-2917.
C.S.E. Bale, T. Ingham, R. Commane, D.E. Heard and W.J. Bloss (2008) Novel Measurements of atmospheric iodine species by resonance fluorescence, J. Atmos. Chem. 60, 51-70.