Expanded Wavelength CAPS-Based Particle SSA Monitor

Measuring the radiative forcing of aerosols is currently the focus of the Department of Energy Atmospheric Sciences Program. Aerosol particles affect the radiative balance of the earth directly, by scattering and absorbing solar and terrestrial radiation, and indirectly, by acting as cloud condensation nuclei. It is now recognized that the atmospheric loading of aerosols generated through human activities can exert an influence on the earths radiation budget comparable in magnitude with greenhouse gases. However, the uncertainties in the current understanding of aerosol direct and indirect forcing limit the ability to quantify human influences on climate change. We are developing a particle single scattering albedo monitor that combines extinction and scattering measurements in one instrument with rapid time-response, active temperature/relative humidity control, and high sensitivity. Its spectral range will include both the near infrared and ultraviolet regions as well as visible wavelengths. This monitor will employ Aerodynes proprietary Cavity Attenuated Phase Shift spectroscopy technology in order to produce a far simpler, smaller, lower cost alternative to cavity ring down-based systems and more traditional instruments with no loss in sensitivity or accuracy. Commercial Applications and Other Benefits: Successful development and marketing of this monitor will yield a significant level of direct commercial sales from the atmospheric sciences and environmental pollution research and development communities. The comparatively low cost and ease of use of this sensor will allow almost routine measurement of the scattering properties of atmospheric aerosols, something precluded by the cost and complexity of current instrumentation.