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- Evgenieva, Tsvetina, et al.
(author)
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Lidar, ceilometer and sun photometer investigation of the aerosol optical characteristics in the troposphere over Sofia, Bulgaria
- 2010
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In: Comptes Rendus de l'Academie Bulgare des Sciences / Proceedings of the Bulgarian Academy of Sciences. - 1310-1331 .- 2367-5535. ; 63:8, s. 1191-1200
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Journal article (peer-reviewed)abstract
- The paper presents the results from planetary boundary layer (PBL) height and aerosol optical depth (AOD) measurements carried out in two different experimental sites in Sofia as well as from three-point measurements of aerosol number concentration.The main aim of the present investigation is to determine optical and microphysical characteristics of the atmospheric aerosol in three points of the valley and their variation during the PBL formation over urban area, park zone and mountain site. Four instruments (lidar, ceilometer, aerosol particle counter and sun photometer) were used in this study.The experimental AOD data obtained at lambda = 500nm gave values in the range from 0.22 to 0.41 in case of cloud-free skies and up to around 0.8 under partly cloudy conditions. Aerosol particle counter data on aerosol-particle concentration variations in the size range 0.3-1 mu m provided supportive information on the evolution of the valley-mountain aerosol in time and height during the mixing layer development. Joint interpretation of sun photometer, aerosol lidar and ceilometer CHM 15k data allow the influence of the main part of the atmospheric aerosol in the planetary boundary layer to be accounted as well as the significant influence of aerosol layers and high clouds on AOD values.
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| 2. |
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| 3. |
- Evgenieva, Tsvetina, et al.
(author)
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Three-point observation in the troposphere over Sofia-Plana Mountain,Bulgaria
- 2011
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In: International Journal of Remote Sensing. - : Informa UK Limited. - 0143-1161 .- 1366-5901. ; 32:24, s. 9343-9363
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Journal article (peer-reviewed)abstract
- Based on a novel combination of approaches and instruments, this article presents campaign-based results from atmospheric boundary layer (ABL) height and aerosol optical depth (AOD) measurements carried out at two different experimental sites in Sofia, as well as from three-point measurements of aerosol number concentrations. Several instruments (lidar (developed by the IE), ceilometer, aerosol particle counter, sun photometer and meteorological sensors) were used in this study. Based on joint interpretation of the instruments' data we assess the influence of the atmospheric aerosol in the planetary boundary layer and the significant influence of aerosol layers and high clouds on AOD values. Measurements of AOD in the city basin gave values in the range 0.22-0.41 for cloud-free skies, and up to around 0.8 under partly cloudy conditions. The information obtained during the two campaigns indicates that aerosol particle concentrations were lower in park areas than along heavy-traffic thoroughfares in the city, but higher than in the mountain area. In conclusion, our study demonstrates the potential of employing a broad array of instruments for the study of boundary layer and aerosol over large, valley-situated and heavily urbanized city areas.
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