Lidar measurements of Raman scattering at ultraviolet wavelength from mineral dust over East Asia

Opt Express. 2011 Jan 17;19(2):1569-81. doi: 10.1364/OE.19.001569.

Abstract

We developed a novel measurement channel that utilizes Raman scattering from silicon dioxide (SiO2) quartz at an ultraviolet wavelength (361 nm). The excitation of the Raman signals is done at the primary wavelength of 355 nm emitted from a lidar instrument. In combination with Raman signals from scattering from nitrogen molecules, we may infer the mineral-quartz-related backscatter coefficient. This technique thus allows us to identify in a comparably direct way the mineral quartz content in mixed pollution plumes that consist, e.g., of a mix of desert dust and urban pollution. We tested the channel for the complex situation of East Asian pollution. We find good agreement of the inferred mineral-quartz-related backscatter coefficient to results obtained with another mineral quartz channel which was operated at 546 nm (primary emission wavelength at 532 nm), the functionality of which has already been shown for a lidar system in Tsukuba (Japan). The advantage of the novel channel is that it provides a better signal-to-noise ratio because of the shorter measurement wavelength.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis*
  • Asia, Eastern
  • Dust / analysis*
  • Environmental Monitoring / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Lasers*
  • Minerals / analysis*
  • Radar*
  • Spectrum Analysis, Raman / instrumentation*
  • Ultraviolet Rays

Substances

  • Air Pollutants
  • Dust
  • Minerals