The distribution of aerosol load in the atmosphere due to two forest fires near Sofia (the capital city of Bulgaria) was studied using two aerosol lidars which operated at 510.6 nm and 1064 nm. Experimental data is presented as 2D-heatmaps of the evolution of attenuated backscatter coefficient profiles and mean profile of the aerosol backscatter coefficient, calculated for each lidar observation. Backscatter related Angstrom exponent was used as a criterion in particle size estimation of detected smoke layers. Calculated minimal values at altitudes where the aerosol layer was observed corresponded to predominant fraction of coarse aerosol. Dust-transport forecast maps and calculations of backward trajectories were employed to make conclusions about aerosol’s origin. They confirmed the local transport of smoke aerosol over the city and lidar station. DREAM forecast maps predicted neither cloud cover, nor Saharan load in the air above Sofia on the days of measurements. The results of lidar observations are discussed in conjunction with meteorological situation, aiming to better explain the reason for the observed aerosol stratification. The data of regular radio sounding of the atmosphere showed a characteristic behavior with small differences of the values between the air temperature and dew-point temperature profiles at aerosol smoke layer altitude. So the resulting stratification revealed the existence of atmospheric layers with aerosol trapping properties.
[1]
Michael Fromm,et al.
Transport of forest fire smoke above the tropopause by supercell convection
,
2003
.
[2]
Tatsuro Tsukamoto,et al.
Characterization of Asian dust and Siberian smoke with multi‐wavelength Raman lidar over Tokyo, Japan in spring 2003
,
2004
.
[3]
Realtime Prediction System of Forest-Fire Smoke using Satellite Data and the PUFF Model: A Case Study for May 2003
,
2005
.
[4]
F. G. Fernald.
Analysis of atmospheric lidar observations: some comments.
,
1984,
Applied optics.
[5]
J. Klett.
Stable analytical inversion solution for processing lidar returns.
,
1981,
Applied optics.
[6]
Massimo Del Guasta.
Daily cycles in urban aerosols observed in Florence (Italy) by means of an automatic 532-1064nm LIDAR
,
2002
.