Highly Time- and Size-Resolved Measurements of Trace Elements during ClearfLo

The identification and quantification of particle sources has long proven challenging due to the complex composition ofambient aerosol. Measurements of trace elements provide unique source-specific information; e.g. barium and copper areemitted by traffic sources, while vanadium and nickel are linked to heavy oil combustion. Here we present highly time- andsize-resolved measurements of trace elements as part of the ClearfLo (Clean Air for London) 2012 field campaign, amultinational collaborative effort to investigate boundary layer pollution in and around London, UK.