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- Evgenieva, Tsvetina, et al.
(författare)
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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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Ingår i: 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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Tidskriftsartikel (refereegranskat)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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- Ibrahim, Muhammad Asim, 1980-, et al.
(författare)
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Mitigating the emissions released from spontaneous fires at biomass storages : A footstep towards sustainability
- 2015
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Ingår i: 23rd European Biomass Conference and Exhibition, Vienna, Austria, 1-4 June 2015. - 9788889407516 ; , s. 1550-1557
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Konferensbidrag (refereegranskat)abstract
- Fires at the material storages sites of manucipal and industrial sectors are a major environmental risk and have increased significantly. Toxic emissions released from such open fires have severe environmental and health consequences. Considering that it is not possible to install any unit operation to control the emissions released from such open fires, the possibilities to employ natural vegetation to act as a sink for aerosol particles released from open fires was investigated. A series of tests was conducted in a controlled wind tunnel environment. Smoke was generated in a smoke-aerosol generator and measurements of smoke concentrations upwind and downwind of “green filter packs” (vegetation filters) were made. Measurements involved laser-based particle counters, two-stage Nuclepore filter systems, and Solid Phase Microextraction (SPME) techniques followed by Gas Chromatography-Mass Spectrometry (GC-MS). The main objective of the work was to illustrate ways to design experiments that can assist in the study of vegetation as “pollution screens”. Our observations and findings imply that several refinements to the experimental design will be needed, including with respect to methods for assessing the distribution of particle number and mass as a function of particle size.
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