Browsing Research Output by Author "630c8e64-9548-4ecd-aef3-47c6e1e31cdf"
Now showing items 1-15 of 15
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100 Years of atmospheric and marine observations at the Finnish Utö Island in the Baltic Sea
Laakso, Lauri; Mikkonen, Santtu; Drebs, Achim; Karjalainen, Anu; Pirinen, Pentti (EGU, 2018)The Utö Atmospheric and Marine Research Station introduced in this paper is located on Utö Island (59°46.84′N, 21°22.13′E) at the outer edge of the Archipelago Sea, by the Baltic Sea towards the Baltic Proper. Meteorological ... -
Assessment of polar organic aerosols at a regional background site in southern Africa
Booyens, Wanda; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Laakso, Lauri (Springer, 2019)A recent paper reported GCxGC-TOFMS analysis used for the first time in southern Africa to tentatively characterise and semi-quantify ~1000 organic compounds in aerosols at Welgegund – a regional background atmospheric ... -
Atmospheric trace metals measured at a regional background site (Welgegund) in South Africa
Venter, Andrew D.; Van Zyl, Pieter G.; Beukes, Johan P.; Josipovic, Micky; Hendriks, Johan; Laakso, Lauri (EGU, 2017)Atmospheric trace metals can cause a variety of health-related and environmental problems. Only a few studies on atmospheric trace metal concentrations have been conducted in South Africa. Therefore the aim of this study ... -
Carbon balance of a grazed savanna grassland ecosystem in South Africa
Räsänen, Matti; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Venter, Andrew D.; Jaars, Kerneels; Siebert, Stefan J.; Laakso, Lauri (EGU, 2017)Tropical savannas and grasslands are estimated to contribute significantly to the total primary production of all terrestrial vegetation. Large parts of African savannas and grasslands are used for agriculture and cattle ... -
The composition of ambient and fresh biomass burning aerosols at a savannah site, South Africa
Aurela, Minna; Beukes, Johan P.; Van Zyl, Pieter; Laakso, Lauri; Vakkari, Ville (ASSAf, 2016)Atmospheric aerosols play a key role in climate change, and have adverse effects on human health. Given South Africa’s status as a rapidly-developing country with increasing urbanisation and industrial growth, information ... -
Global analysis of continental boundary layer new particle formation based on long-term measurements
Nieminen, Tuomo; Beukes, Johan Paul; Laakso, Lauri; Kerminen, Veli-Matti; Petäjä, Tuukka (EGU, 2018)Atmospheric new particle formation (NPF) is an important phenomenon in terms of global particle number concentrations. Here we investigated the frequency of NPF, formation rates of 10 nm particles, and growth rates in ... -
Measurements of biogenic volatile organic compounds at a grazed savannah grassland agricultural landscape in South Africa
Jaars, Kerneels; Van Zyl, Pieter G.; Beukes, Johan P.; Josipovic, Micky; Venter, Andrew D.; Knoetze, Leandra; Cilliers, Dirk P.; Siebert, Stefan J.; Laakso, Lauri (EGU, 2016)Biogenic volatile organic compounds (BVOCs) play an important role in the chemistry of the troposphere, especially in the formation of tropospheric ozone (O3) and secondary organic aerosols (SOA). Ecosystems produce and ... -
Measuring turbulent CO2 fluxes with a closed-path gas analyzer in a marine environment
Honkanen, Martti; Laakso, Lauri; Tuovinen, Juha-Pekka; Laurila, Tuomas; Makela, Timo (EGU, 2018)In this study, we introduce new observations of sea–air fluxes of carbon dioxide using the eddy covariance method. The measurements took place at the Utö Atmospheric and Marine Research Station on the island of Utö in the ... -
OMI satellite and ground-based Pandora observations and their application to surface NO2 estimations at terrestrial and marine sites
Kollonige, Debra E.; Thompson, Anne M.; Josipovic, Miroslav; Beukes, Johan P.; Burger, Roelof; Van Zyl, Pieter G.; Laakso, Lauri (Wiley, 2018)The Pandora spectrometer that uses direct-Sun measurements to derive total column amounts of gases provides an approach for (1) validation of satellite instruments and (2) monitoring of total column (TC) ozone (O3) and ... -
Rapid changes in biomass burning aerosols by atmospheric oxidation
Vakkari, Ville; Beukes, Johan Paul; Tiitta, Petri; Van Zyl, Pieter G.; Josipovic, Miroslav; Venter, Andrew D.; Jaars, Kerneels; Laakso, Lauri (Wiley, 2014)Primary and secondary aerosol particles originating from biomass burning contribute significantly to the atmospheric aerosol budget and thereby to both direct and indirect radiative forcing. Based on detailed measurements ... -
Size-resolved characteristics of inorganic ionic species in atmospheric aerosols at a regional background site on the South African Highveld
Venter, Andrew D.; Van Zyl, Pieter G.; Beukes, Johan P.; Swartz, Jan-Stefan; Josipovic, Miroslav; Laakso, Lauri (Springer, 2018)Aerosols consist of organic and inorganic species, and the composition and concentration of these species depends on their sources, chemical transformation and sinks. In this study an assessment of major inorganic ions ... -
Size-resolved characteristics of inorganic ionic species in atmospheric aerosols at a regional background site on the South African Highveld North-West University’s research published in Journal of Atmospheric Chemistry. (Research brief)
Venter, Andrew D.; Van Zyl, Pieter G.; Beukes, Johan P.; Swartz, Jan-Stefan; Josipovic, Miroslav; Laakso, Lauri (NACA, 2018) -
Spatial, temporal and source contribution assessments of black carbon over the northern interior of South Africa
Chiloane, Kgaugelo Euphinia; Beukes, Johan Paul; Van Zyl, Pieter Gideon; Maritz, Petra; Josipovic, Miroslav; Venter, Andrew Derick; Jaars, Kerneels; Tiitta, Petri; Laakso, Lauri (EGU, 2017)After carbon dioxide (CO2), aerosol black carbon (BC) is considered to be the second most important contributor to global warming. This paper presents equivalent black carbon (eBC) (derived from an optical absorption method) ... -
Submicrometer aerosols and excess CO as tracers for biomass burning air mass transport over southern Africa
Mafusire, Getrude; Beukes, Johan Paul; Josipovic, Miroslav; Van Zyl, Pieter Gideon; Laakso, Lauri (Wiley, 2016)This paper links surface measurements of biomass burning aerosols and trace gases with trajectory analysis to determine transport pathways for air masses with high and low concentrations. We interpret the long-term ... -
Summary of research paper published in Journal of Atmospheric Chemistry titled: Assessment of polar organic aerosols at a regional background site in southern Africa
Booyens, Wanda; Beukes, Johan P.; Van Zyl, Pieter G.; Josipovic, Miroslav; Laakso, Lauri (National Association for Clean Air, 2019)A recent paper reported GCxGC-TOFMS analysis used for the first time in southern Africa to tentatively characterise and semiquantify ~1 000 organic compounds in aerosols at Welgegund – a regional background atmospheric ...