English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Southern Africa is a significant source region of atmospheric pollution, yetlong-term data on pollutant concentrations and properties from this regionare rather limited. A recently established atmospheric measurement stationin South Africa, Welgegund, is strategically situated to capture regionalbackground concentrations, as well as emissions from the major sourceregions in the interior of South Africa. We measured non-refractivesubmicron aerosols (NR-PM<sub>1</sub>) and black carbon over a one year period inWelgegund, and investigated the seasonal and diurnal patterns of aerosolconcentration levels, chemical composition, acidity and oxidation level.Based on air mass back trajectories, four distinct source regions weredetermined for NR-PM<sub>1</sub>. Supporting data utilised in our analysisincluded particle number size distributions, aerosol absorption, trace gasconcentrations, meteorological variables and the flux of carbon dioxide.  The dominant submicron aerosol constituent during the dry season was organicaerosol, reflecting high contribution from savannah fires and othercombustion sources. Organic aerosol concentrations were lower during the wetseason, presumably due to wet deposition as well as reduced emissions fromcombustion sources. Sulfate concentrations were usually high and exceededorganic aerosol concentrations when air-masses were transported over regionscontaining major point sources. Sulfate and nitrate concentrations peakedwhen air masses passed over the industrial Highveld(iHV) area. In contrast, concentrations were much lower when air massespassed over the cleaner background (BG) areas. Air masses associated withthe anti-cyclonic recirculation (ACBIC) source region contained largely agedOA.  Positive Matrix Factorization (PMF) analysis of aerosol mass spectra wasused to characterise the organic aerosol (OA) properties. The factorsidentified were oxidized organic aerosols (OOA) and biomass burning organicaerosols (BBOA) in the dry season and low-volatile (LV-OOA) andsemi-volatile (SV-OOA) organic aerosols in the wet season. The resultshighlight the importance of primary BBOA in the dry season, whichrepresented 33% of the total OA. Aerosol acidity and its potential impacton the evolution of OOA are also discussed

Chemical composition, main sources and temporal variability of PM&lt;sub&gt;1&lt;/sub&gt; aerosols in southern African grassland

Chemical composition, main sources and temporal variability of PM<sub>1</sub> aerosols in southern African grassland