Particulate matter (PM) can affect climate, air quality, human health, acid deposition and visibility, and contain a significant fraction of organic (OC) and elemental carbon (EC). Southern Africa is an important source region for OC and EC, however, little OC and EC data have been published for this region. This paper presents a multi-year, multi-site (an urban-industrial site in the Vaal Triangle, UI-VT; an industrially influenced site at Amerfoort, iI-AF; and two regional background sites at Skukuza and Louis Trichardt, RR-SK and RR-LT) PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5) OC and EC dataset for South Africa. The median OC (9.3) and EC (3.2 μg.m−3) concentrations at UI-VT were 1.3 to 2.5 and 2.7 to 4.4 times higher, if compared to the other sites. OC/EC ratios indicated that sources in close proximity to UI-VT were likely the main contributors, while sources that are more distant contributed fractionally more at the other sites. Household combustion for space heating and regional open biomass burning contributed to elevated levels during the cold and dry months at UI-VT. Regional open biomass burning also lead to higher OC and EC concentrations during the dry season at the industrially influenced site (iI-AF) and one of the regional background sites (RR-SK). From the seasonal concentration patterns, it seemed as if household combustion for space heating also contributed at these two sites during the cold months, but this could not be proven, even if only samples with limited influence of open biomass burning were considered. Such biomass burning influences were semi-quantified by considering MODIS fire pixels occurring within the air mass fetch region for each sample. For the remaining regional background site (RR-LT) the results suggesed that only regional open biomass burning contributed to elevated levels of OC and EC in the dry season and that household combustion for space heating did not contribute significantly.

中文翻译：

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南非北部内陆地区有机碳和元素碳的时间和来源评估

颗粒物 (PM) 会影响气候、空气质量、人类健康、酸沉降和能见度，并且含有大量有机 (OC) 和元素碳 (EC)。南部非洲是 OC 和 EC 的重要来源地区，但该地区的 OC 和 EC 数据很少。本文介绍了一个多年、多站点（位于 UI-VT 的瓦尔三角区的城市工业站点；位于 I-AF 的阿默福特的受工业影响站点；以及位于斯库库扎和路易斯特里查特的两个区域背景站点，RR- SK 和 RR-LT) PM，空气动力学直径 ≤ 2.5 μm (PM2.5) 南非的 OC 和 EC 数据集。如果与其他站点相比，UI-VT 的中值 OC (9.3) 和 EC (3.2 μg.m-3) 浓度分别高出 1.3 到 2.5 和 2.7 到 4.4 倍。OC/EC 比率表明，靠近 UI-VT 的源可能是主要贡献者，而更远的源在其他站点的贡献略多。在 UI-VT 寒冷干燥的月份，用于空间供暖和区域开放生物质燃烧的家庭燃烧导致水平升高。在受工业影响的地点 (iI-AF) 和区域背景地点之一 (RR-SK) 的旱季，区域露天生物质燃烧也会导致较高的 OC 和 EC 浓度。从季节性集中模式来看，在寒冷的月份，这两个地点似乎也有用于取暖的家庭燃烧，但这无法得到证实，即使只考虑了开放生物质燃烧影响有限的样本。通过考虑每个样本的气团提取区域内发生的 MODIS 火灾像素，可以对这种生物质燃烧影响进行半量化。对于剩余的区域背景站点 (RR-LT)，结果表明，只有区域露天生物质燃烧导致旱季 OC 和 EC 水平升高，而用于取暖的家庭燃烧没有显着贡献。