Research

Current Research:

BC particleInvestigating the distribution and effects of carbonaceous absorbing aerosols over mainland China

BACKGROUND:

Black carbon (BC) and "brown" organic carbon (BrC) particles are emitted to the atmosphere by incomplete combustion. These carbonaceous aerosols efficiently absorb solar radiation, with complicated impacts on climate. Recent studies suggest that BC and BrC may exert a positive feedback on aerosol and atmospheric pollution accumulation. My work involves examining the chemical and meteorological factors that affect atmospheric pollution in China, with a particular focus on carbonaceous absorbing aerosols.

OBJECTIVES

  • Use in situ data to understand the distribution and trends of BC and BrC in China.
  • Improve the ability of models to simulate BC and BrC concentrations over China.
  • Determine the implications for regional climate forcing.
  • Determine the importance of absorbing aerosols in the formation of extreme air pollution events.

HMSHydroxymethanesulfonate in particulate matter

BACKGROUND:

Hydroxymethanesulfonate (HMS) is formed by the aqueous phase reaction of formaldehyde and sulfite or bisulfite. While HMS chemistry is well understood and was included in many early atmospheric chemistry models, this chemical pathway has been mostly overlooked since the late 1980s. Importantly, HMS can be confused for sulfate in measurements. This may have led to the misidentification of HMS as sulfate in measurements of PM2.5 chemical composition. This implies that, where HMS comprises a significant portion of particulate sulfur, reductions of formaldehyde may also be an effective tool at reducing particulate air pollution.

OBJECTIVES

  • Understand the significance of HMS in particulate matter during extreme haze in China.
  • Determine the importance of HMS globally.
  • Determine the effectiveness of reducing formaldehyde versus reducing sulfur dioxide for PM2.5 concentrations.