Aerosol data measured by polarization lidar over Hefei in spring of 2005～2008 are analysed again. The observational results on Mar. 2nd, 2008 are used for case study and 137 samples of aerosol layers are investigated statistically. The results show that 70% of the average heights for these layers is ranged from 2 to 4 km, and the value of depolarization ratio for them, which is lager than 0.1, takes up to 85%, and these aerosol layers are sourced from the dust particles, which are transported in long range from the dust regions. These results can used to interpret why the aerosol concentration in free troposphere over Hefei in spring is higher than other seasons.

In order to investigate the tropospheric aerosol optical properties over Hefei, a combined Raman elastic-backscatter lidar was developed for vertical profiling aerosol extinction, backscatter and lidar ratio. The lidar and data processing were introduced, and some measurements were presented. The temporal and vertical variations of the aerosol backscatter coefficient in the troposphere were observed using the lidar during the passage of the cold front, an amount of particles could be taken to Hefei with the cold air mass, the vertical distribution of the aerosol in the lower troposphere varied extremely, and the height of the top of mixing layer could be lifted up to about 3 km above ground level. The comparisons between aerosol optical properties retrieved using Fernald method and Raman method showed that extinction, backscatter and lidar ratio profiles in the lifted aerosol layer cloud be measured using the lidar.

The polarization micro-pulse lidar (PMPL) is with such anvangtages as small size, low cost, high movability, and stable performance. After the introduction of the princile, structure and specification, a PMPL 24-hour-continued-measurement sample at Guangzhou on Nov. 23, 2009 is shown, which reveals a pollutant process and its variation.

The geometric factors of two receiver channels in differential absorption lidar are not exactly the same, and result in certain bias in near range for retrieval pollutant density. Based on the analysis of formation of channal geometric factor, the ratio of channel geometric factors is proposed for correction, and the method of measuring the ratio of channel geometric factors is introduced. Experimental results show that this correction method is reliable and practical.

Based on updated daily surface solar radiation and associated meteorological elements data from 13 observational stations over East China, the long term trend of surface total solar radiation was analyzed, and the influence of cloud, aerosol and water vapor on total solar radiation were explored. The total solar radiation decreased from 1961～2008 at a rate of 2.05 W·m-2·(10yr)-1; it decreased obviously from 1961 to 1989, and increased from 1990 to 1995, but decreased again since 1995, after 2000 fluctuated in the average line and slightly increased. The change of aerosol, cloud and water vapor contribute much to the variation of total radiation, from 1961 to 1989, the results imply that the atmospheric aerosols burden enhancement is the major reason for global radiation reduction, while cloud cover’s contribution is relatively larger from 1990 to 2008, and the influence on total solar radiation of the low cloud is greater than that of the total cloud.

The errors of atmospheric aerosol optical thickness obtained from Sun-photometer measurements, due to uncertainties of calibration coefficients, are analyzed. The precise formulae of errors analysis are deduced. The numerical experiments are carried out to investigate the absolute errors of aerosol optical thickness, caused by uncertainty of calibration coefficients. The simulative results indicate that calibration errors of less than +2% are suitable for aerosol optical thickness measurements.

Atmospheric wind field is an important side in researching the process of aerosol transportation and compounding, and the diversification of aerosol space-time distribution. It is also an essential parameter of the synoptic analysis and weather forecast. The structure and theory of sounding system of wind field—wind profiler radar was introduced. From analyzing the data in plum rain season, the evolving of wind field in one synoptic process was observed. And from the statistics of wind field in 2009, Hefei, it can be concluded the following points. In the boundary layer (under 2 km), the wind velocity was below 5 m/s, and the wind direction was complex and had some diversity in different seasons. In the troposphere, the wind velocity was generally between 5 m/s and 25 m/s, and the predominant wind direction was west wind. The maximum wind velocity had exceeded 60 m/s.

Atmospheric physic and optical properties in Science Island, Hefei were continuously measured and statistically analyzed from January 29 to 31, in 2008. The characteristic parameters, such as temperature, relative humidity, wind velocity, turbulence refractive index constant, size distribution of aerosol particles, total number concentration, scattering coefficient and absorption coefficient were measured synchronously. Some of statistical results had distinct difference with results of routine measurement in winter. The variation of aerosol in the case was discussed.

It is important to measure and estimate turbulent flux in surface layer for study air-land interaction. The data of radiation flux and CO2 concentration in fine weather from 10 January 2007 to 14 October 2010, in Hefei have been analysed statistically. The characteristics of season variation and diurnal of albedo and net radiation flux have been obtained. The experiment of surface energy budget shows that there are about 40% energy closure gaps in daytime. The data from 2007-2010 show that CO2 concentration in winter,spring,autumn and summer is 735 mg·m-3, 704.4 mg·m-3, 701.8 mg·m-3, and 692.6 mg·m-3 respectively. The turbulent fluxes estimated by dissipation methods and measured by eddy correlation have been compared.

Yuexi County, located in the Dabie Mountain area, is a typical mountain. The ozone analyzer EC9810, multi-channel optical particle counter OPC-06 and instrument of carbon black are used to measure the atmospheric parameters from May 22 to June 10, 2009. The ozone and aerosol size distribution and their daily variation are obtained. Those data are compared with the ones measured at Hefei. The comparison indicates: (1) ozone level in Hefei is significantly higher than that at Changpu Town in Yuexi County; (2) aerosol types are different between Hefei and Changpu; (3) aerosol absorption coefficient is significantly higher in Hefei than that in the mountain, and aerosol absorption wavelength index is smaller in Hefei than that in Changpu.