The characterisation of mineral dust at emission sources is essential for quantifying the wider-scale environmental impacts dust has, as well as improving its incorporation in modelling. Methods of sampling sediments at these source areas for the purposes of dust characterisation are varied and can produce different representations of emitted dust. This study systematically compared dust characterisations from three established approaches for estimating dust emission potential, namely: Big Spring Number Eight (BSNE) traps, a Portable In-situ Wind Erosion Laboratory (PI-SWERL) wind tunnel, and bulk surface sampling, at a known Namib Desert dust source. Individual particle analysis by auto-SEM (QEMSCAN) allowed comparison of size, shape, mineralogy and elemental composition at micrometre-scale for samples from the three approaches. BSNE samples consisted of a lower proportion of fine sediment (<20 µm particle diameter) than PI-SWERL-derived samples, with this performance possibly influenced by atmospheric humidity. In comparison, PI-SWERL characterised the dust with relatively fewer particles between 63 and 100 µm, a fraction that was more evident in both the BSNE-derived and surface sediments. The reduced representation of this coarser fraction resulted in appreciable differences in particle shape and mineralogic characteristics compared to BSNE and surface-derived samples. The different representations by the three methods return variable dust characteristics at source across fundamental properties of particle size, shape and mineralogy. Awareness of the different representations of dust caused by sampling technique remains essential for the appropriate physical and geochemical characterisation of aeolian dust and highlights how standardised techniques are important for meaningful comparisons, while methods to achieve accurate characterisation remain a priority for the discipline.

排放源中矿物粉尘的表征对于量化粉尘对更广泛的环境影响以及改善其在建模中的结合至关重要。为了表征粉尘，在这些源头区域对沉积物进行采样的方法多种多样，并且可以产生不同形式的排放粉尘。这项研究系统地比较了三种用于估算粉尘排放潜力的既定方法的粉尘特征，即：八号大弹簧捕集阱（BSNE），便携式原位风蚀实验室（PI-SWERL）风洞和散装表面采样。已知的纳米布沙漠尘埃源。通过自动SEM（QEMSCAN）进行的单个颗粒分析，可以比较三种方法中的样品的微米级尺寸，形状，矿物学和元素组成。BSNE样品的细颗粒沉积物（<20 µm粒径）的比例低于PI-SWERL样品，该性能可能受大气湿度的影响。相比之下，PI-SWERL对粉尘的特征是在63到100 µm之间的颗粒相对较少，这在BSNE来源的沉积物和表面沉积物中都更为明显。与BSNE和表面衍生的样品相比，该较粗级分的减少的表示导致了颗粒形状和矿物学特征的明显差异。三种方法的不同表示形式会在粒径，形状和矿物学的基本属性上从源头返回可变的粉尘特性。