VRNPS

The purpose of this campaign is to measure vertically resolved concentrations of nucleation precursor gases to understand how and why nucleation occurs above the surface layer at ARM’s Southern Great Plains (SGP) atmospheric observatory. We propose two key objectives to achieve this broad goal: (1) measure nucleation precursors and particles at various altitudes (0-1000 m) at SGP using the tethered balloon system (TBS) and (2) determine how vertically distributed nucleation precursors contribute to new-particle formation rates above the surface layer and how precursor concentrations can be explained by meteorological conditions and atmospheric turbulence measured by ARM SGP value-added products.

A newly developed set of reactive condensation particle counters (RCPCs) will be deployed at the ground site (guest instrument facility [GIF]) and on the TBS. The RCPCS can measure the concentrations of nucleation precursor compounds, specifically sulfuric acid and combined effective basic gases. In addition, a chemical ionization mass spectrometer (CIMS) and scanning mobility particle sizer (SMPS) will be deployed at the SGP GIF to measure ground-level concentrations of nucleation precursors and freshly nucleated particles. Our vertically resolved nucleation precursor measurements will be combined with local observations of meteorology, cloud conditions, and atmospheric turbulence to understand how emissions from ground-level sources are transported and nucleate above the surface layer.

Timeline