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Observation Study on the Optical Properties of Aerosol Particles over Zhangye

Author: XiangTao
Tutor: ZhangWu
School: Lanzhou University
Course: Applied Meteorology
Keywords: Zhangye Aerosol Scattering Absorb Optical thickness
CLC: X513
Type: Master's thesis
Year: 2011
Downloads: 33
Quote: 0
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Abstract

In this paper, from April to June 2008, China - United dust aerosol observation trial data, analyzes Zhangye station location aerosol absorption, scattering and optical thickness and other features. The main conclusions are as follows: 1) the absorption coefficient of aerosols hour average mean (standard deviation) of 11.9Mm-1 (10.2Mm-1), scattering coefficient mean (standard deviation) of 96Mm-1 (115Mm-1) . AOD average of 0.39 (0.32). On the whole, the region scattering and absorption coefficients are compared with observations in eastern China is small, which is the region's level of industrialization and economic development are closely related. 2) changes in the absorption and scattering coefficients more intense. Absorption coefficient is affected by human activities, mainly aerosol emissions and atmospheric dispersion conditions affecting the diurnal variation; while scattering coefficient changes in addition to the above two factors, but also influenced by the sandstorm. In the non-dust scattering coefficient and the absorption coefficient at the diurnal variation showed a clear \And the scattering and absorption coefficients at night than during the day was. 3) non-dust day diurnal variation of aerosol optical thickness relatively flat, the trend in one day is the first rise, then relatively stable. Non-dust day daily average aerosol optical depth is generally less than 0.5, and the dust aerosol optical thickness at more than 0.5, and even more than 1.4) due to the special valley terrain, wind direction in the region significantly in one day conversion, showing obvious valley wind characteristics. East of midnight to 10:00 am southerly oriented, 11:00 to 20:00 in the northwest wind driven. The remaining time is dominated by southerly winds. The maximum wind speed appeared one day in the afternoon 15:00. 5) daily average PM10 concentrations observed during the change is more intense, mainly with dust weather. There are 18-day daily average PM10 concentrations exceed the national ambient air quality standard of two (150μg/m3), accounting for the total number of days observed for 30%, while in the non-dust day daily average PM10 concentrations mostly in 100μg/m3 so. 6) when the observation point in the southeast wind, aerosol absorption and scattering coefficients are often prone to a higher value, but the aerosol optical thickness values ??are often low. Northwest wind, the absorption and scattering coefficients are often prone to a lower value, but the value of the aerosol optical thickness but often appear greater. Although Northwest winds often bring to more dust aerosols, making observation points have a certain scattering coefficient increases. But by the impact of observation points southeast wind aerosol absorption and scattering coefficients significantly higher than the northwest wind affected by the absorption and scattering coefficients. For the optical thickness, the northwest wind affect the optical thickness was significantly higher than the level of impact on the level of the southeast wind. In addition to southeast winds and northwest wind, the southerly winds and southerly to southwesterly winds carry aerosol absorption, scattering coefficient and aerosol optical thickness average is higher. 7) Depending on the source will affect the aerosol into the observation point pollutant emissions from human activities and natural factors mainly due to emissions of dust aerosols. Two kinds of aerosol scattering and absorption efficiency of a clear difference between the quality of aerosol contamination of dust aerosol scattering coefficient close to 2 times, and the mass absorption coefficient of aerosol contamination is an order of magnitude than the dust aerosol . Two kinds of aerosols are often mixed together, so that the region aerosol characteristics of scattering coefficient and absorption coefficient is more complex.

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