Narrow Results

Accurate quantifications of aerosol components are crucial to predict global atmospheric transport models. Recently developed International Monitoring System (IMS) network represents an opportunity to enhance comprehensive systematic aerosol observations on a global scale because it provides a global infrastructure. As such, a local pilot study utilizing several state-of-the-art instruments has been conducted at the peak of the Rattlesnake Mountain, Washington, USA, during three month periods (June-August) in 2003 to explore this opportunity. In this study, routine aerosol samples were collected using a 3-stage Cascade Impactor Beam Analyzer (0.07 to 2.5 µm) with time resolution about 6 hours on long Teflon strips while radionuclide aerosols were collected using Radionuclide aerosol sampler/analyzer (RASA) developed at Pacific Northwest National Laboratory. The elemental composition and hydrogen concentration were measured using proton induced x-ray emission (PIXE) and proton elastic scattering analysis (PESA), respectively. In addition, short and long-lived radionuclides that exist in nature were measured with same time resolution (6 hours) using RASA. In this method, high-resolution gamma-ray spectra were analyzed for radionuclide concentration. Combination of trace radioactive and non-radioactive element analysis in aerosols makes this investigation unique.

The New Zealand capability in Ion Beam Analysis of air particulate samples has been upgraded in recent years. The main equipment change has been the introduction of the ability to analyse samples taken using the Streaker (PIXE International Corporation) sampling system. This is an automated sampler which allows for great flexibility in monitoring programmes by collecting particulates for up to about 70 sampling periods which can range in collection times from seconds to many hours. The IBA analysis for hydrogen on standard filters and for PIXE multi-elemental analysis of the Streaker filters has also been studied with a view to optimising analytical methods.