Atmospheric aerosol extinction coefficient measuring method based on cavity ring-down spectroscopy technology

Abstract

The invention discloses an atmospheric aerosol extinction coefficient measuring method based on a cavity ring-down spectroscopy technology. The cavity ring-down spectroscopy technology is a novel spectrum detection technology, is designed based on the multi-reflection characteristics of a high-reflection mirror, has the advantages of ultra-high sensitivity and low detection limit and provides a novel measuring method for aerosol extinction measurement. A cavity mirror has a very high reflection rate of 99.9-99.9999% and a slow light intensity damping rate, realizes an equivalent optical path of several kilometers or even several tens of kilometers in a cavity and greatly improves the sensitivity and detection limit. The atmospheric aerosol extinction coefficient measuring method based on acavity ring-down spectroscopy technology has sensitivity of 0.2 Mm<-1> more higher than the extinction coefficient detection sensitivity of the traditional extinction coefficient detection method.

Description

technical field [0001] The invention relates to a method for measuring the extinction coefficient of atmospheric aerosol, in particular to a method for measuring the extinction coefficient of atmospheric aerosol based on cavity ring-down spectroscopy technology. Background technique [0002] Atmospheric aerosols refer to liquid or solid particles suspended in the atmosphere, usually with a particle diameter (aerodynamic diameter) between 0.003-100 μm. Atmospheric aerosols can affect the Earth's atmospheric energy budget by scattering and absorbing solar radiation, thereby affecting climate change. This effect is called the direct radiation effect of aerosols. The direct radiative effect of aerosols depends on the optical properties of aerosols, mainly including the scattering and absorption of light by aerosols. The extinction of aerosol is the result of the combined effect of aerosol scattering and absorption characteristics, and the extinction coefficient is the sum of th...

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Problems solved by technology

Although lidar has high spatial resolution, this method is usually only applicable to a certain type of aerosol, and the error is relatively large for aerosols with fast time scale changes, and when the concentration of aerosols in the atmosphere is low , the detection sensitivity is low, and the technology is also greatly affected by weather and atmosphere

The integral turbidity meter is portable and the cost is moderate, but when measuring in a high relative humidity environment, the system error is obviously too large. Even after being corrected by the traditional correction factor, the measurement result is usually low due to the large truncation error

For the black carbon meter, although it has the advantages of simple measurement method and low price, because the measurement method is affected by the type and characteristics of the filter membrane, the scattering or absorbing aerosol collected on the filter membrane will interact with the filter membrane and change The absorptive nature of aerosols can lead to an overestimation of the absorption coefficient

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