Now showing items 1-12 of 12

    • An air quality assessment in the industrialised western Bushveld Igneous Complex, South Africa 

      Venter, Andrew D.; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Pienaar, Jacobus J.; Tiitta, Petri; Laakso, Lauri (ASSAf, 2012)
      South Africa has the largest industrialised economy in Africa, with significant mining and metallurgical activities. A large fraction of the South African mineral assets is concentrated in the Bushveld Igneous Complex ...
    • Assessment of atmospheric trace metals in the western Bushveld Igneous Complex, South Africa 

      Van Zyl, Pieter G.; Beukes, Johan P.; Du Toit, Grizelda; Hendriks, Johan; Pienaar, Jacobus J.; Laakso, Lauri (ASSAf, 2014)
      Trace metal species emitted into the atmosphere from natural and anthropogenic sources can cause various health-related and environmental problems. Limited data exist for atmospheric trace metal concentrations in South ...
    • Automated continuous air monitoring 

      Beukes, Johan Paul; Venter, Andrew Derick; Josipovic, Miroslav; Van Zyl, Pieter Gideon; Jaars, Kerneels; Dunn, Marcell; Laakso, Lauri (Elsevier, 2015)
      Anthropogenic and anthropogenically induced emissions (such as emissions due to land use change) of various gaseous and particulate atmospheric species have substantially increased since the onset of the industrial ...
    • Characterising particulate organic nitrogen at a savannah-grassland region in South Africa 

      Booyens, Wanda; Van Zyl, Pieter G.; Beukes, Johan P.; Vakkari, Ville; Josipovic, Miroslav; Laakso, Lauri (MDPI, 2019)
      Although atmospheric organic N compounds are considered to be important, especially in new particle formation and their contribution to brown carbon, these species are not that well understood. This can be partially ...
    • A comparison of surface NO2 mixing ratios and total column observations at a South African site 

      Josipovic, Micky; Burger, Roelof P.; Thompson, Anne M.; Beukes, Johan P.; Van Zyl, Pieter G.; Venter, Andrew D.; Jaars, Kerneels; Laakso, Lauri (SASAS, 2014)
      The total column density nitrogen dioxide (NO2) retrievals collated by a ground-based sun-tracking spectrometer (Pandora/GSFC) and the satellite-borne (Aura) Ozone Monitoring Instrument (OMI) were compared to the volume ...
    • The effect of rainfall amount and timing on annual transpiration in grazed savanna grassland 

      Räsänen, Matti; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Siebert, Stefan J.; Laakso, Lauri (EGU, 2020)
      The role of precipitation (P) variability on evapotranspiration (ET) and its two components transpiration (T) and evaporation (E) rates from savannas continues to draw significant research interest given its relevance to ...
    • Free tropospheric aerosols over South Africa 

      Elina, Giannakaki; Laakso, Lauri; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Tiitta, Petri; Chiloane, Kgaugelo; Piketh, Stuart (EDP Sciences, 2016)
      Raman lidar data of one year was been analyzed to obtain information relating aerosol layers in the free troposphere over South Africa, Elandsfontein. In total, 375 layers were observed above the boundary layer during the ...
    • Modelling new particle formation events in the South African savannah 

      Gierens, Rosa T.; Laakso, Lauri; Beukes, Johan P.; Van Zyl, Pieter G.; Pienaar, Jacobus J. (ASSAf, 2014)
      Africa is one of the less studied continents with respect to atmospheric aerosols. Savannahs are complex dynamic systems sensitive to climate and land-use changes, but the interaction of these systems with the atmosphere ...
    • Ozone concentrations and their potential impacts on Vegetation in Southern Africa 

      Laakso, Lauri; Beukes, Johan Paul; Van Zyl, Pieter Gideon; Pienaar, Jacobus J.; Josipovic, Miroslav; Venter, Andrew; Jaars, Kerneels (Elsevier, 2013)
      The tropospheric ozone concentrations over southern Africa are relatively high due to large precursor emissions from biomass burning, vegetation and anthropogenic sources and the intensity of solar radiation. In this study, ...
    • Root-zone soil moisture variability across African savannas: from pulsed rainfall to land-cover switches 

      Räsänen, Matti; Vakkari, Ville; Laakso, Lauri; Beukes, J. Paul; Van Zyl, Pieter G.; Josipovic, Miroslav (Wiley, 2020)
      The main source of soil moisture variability in savanna ecosystems is pulsed rainfall. Rainfall pulsing impacts water‐stress durations, soil moisture switching between wet‐to‐dry and dry‐to‐wet states, and soil moisture ...
    • Six-year observations of aerosol optical properties at a southern African grassland savannah site 

      Venter, Marcell; Beukes, Johan Paul; Van Zyl, Pieter Gideon; Vakkari, Ville; Josipovic, Miroslav; Laakso, Lauri (Elsevier, 2020)
      Atmospheric aerosols have a significant effect on earth's radiative budget, particularly on regional scales. This paper presents a ~6 year, in situ, ground level aerosol scattering and absorption dataset, measured at a ...
    • Size-resolved characterisation of organic compounds in atmospheric aerosols collected at Welgegund, South Africa 

      Booyens, Wanda; Van Zyl, Pieter G.; Beukes, Johan P.; Josipovic, Miroslav; Venter, Andrew D.; Jaars, Kerneels; Pienaar, Jacobus J.; Laakso, Lauri (Springer, 2015)
      The organic fraction of atmospheric aerosols is 20 to 90 % of which only a small percentage has been chemically characterised. Two-dimensional gas chromatography with a time-of-flight mass spectrometer (GCxGC-TOFMS) is a ...