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Observation and Analysis of Blinking Surface-enhanced Raman Scattering
Published on: January 11, 2018
Particle backscatter, extinction, and lidar ratio profiling with Raman lidar in south and north China
Matthias Tesche1, Albert Ansmann, Detlef Müller
1Leibniz Institute for Tropospheric Research, Permoserstrasse 15, 04318 Leipzig, Germany. tesche@tropos.de
Applied Optics
|September 7, 2007
Summary
Aerosol lidar measurements revealed distinct differences in particle properties between polluted Pearl River Delta haze and cleaner Beijing air. Lower lidar ratios in Beijing suggest cleaner air masses, potentially influenced by Gobi dust.
Area of Science:
- Atmospheric Science
- Aerosol Physics
- Lidar Remote Sensing
Background:
- Aerosol properties significantly impact air quality and climate.
- Understanding aerosol optical properties is crucial for climate modeling.
- Lidar provides valuable data on aerosol vertical profiles.
Purpose of the Study:
- To investigate aerosol optical properties under different pollution conditions.
- To compare lidar ratios in polluted (Pearl River Delta) and cleaner (Beijing) environments.
- To analyze the influence of air mass origin on aerosol characteristics.
Main Methods:
- Aerosol Raman lidar observations were conducted in the Pearl River Delta and Beijing.
- Particle extinction and backscatter coefficients were measured.
- Extinction-to-backscatter ratio (lidar ratio) was calculated.
Main Results:
- Highly polluted haze in the Pearl River Delta showed high extinction coefficients (200-800 Mm-1) and lidar ratios (40-55 sr).
- Cleaner air masses in Beijing exhibited lower extinction (100-300 Mm-1) and lidar ratios (30-45 sr), with some Gobi dust influence.
- Unexpectedly low lidar ratios (~25 sr) were observed for background aerosol, consistent with Mie scattering calculations.
Conclusions:
- Aerosol optical properties vary significantly with pollution levels and air mass origin.
- Lidar ratio is a key indicator differentiating aerosol types and pollution levels.
- Mie scattering calculations support the interpretation of low lidar ratios in clean conditions.
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