Prospero J M
University of Miami, Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway, Miami, FL 33149, USA.
Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3396-403. doi: 10.1073/pnas.96.7.3396.
Soil dust is a major constituent of airborne particles in the global atmosphere. Dust plumes frequently cover huge areas of the earth; they are one of the most prominent and commonly visible features in satellite imagery. Dust is believed to play a role in many biogeochemical processes, but the importance of dust in these processes is not well understood because of the dearth of information about the global distribution of dust and its physical, chemical, and mineralogical properties. This paper describes some features of the large-scale distribution of dust and identifies some of the geological characteristics of important source areas. The transport of dust from North Africa is presented as an example of possible long-range dust effects, and the impact of African dust on environmental processes in the western North Atlantic and the southeastern United States is assessed. Dust transported over long distances usually has a mass median diameter <10 microm. Small wind-borne soil particles show signs of extensive weathering; consequently, the physical and chemical properties of the particles will greatly depend on the weathering history in the source region and on the subsequent modifications that occur during transit in the atmosphere (typically a period of a week or more). To fully understand the role of dust in the environment and in human health, mineralogists will have to work closely with scientists in other disciplines to characterize the properties of mineral particles as an ensemble and as individual particles especially with regard to surface characteristics.
土壤尘埃是全球大气中空气传播颗粒的主要成分。尘埃羽流经常覆盖地球的大片区域；它们是卫星图像中最显著且最常见的特征之一。尘埃被认为在许多生物地球化学过程中发挥作用，但由于缺乏关于尘埃全球分布及其物理、化学和矿物学性质的信息，尘埃在这些过程中的重要性尚未得到充分理解。本文描述了尘埃大规模分布的一些特征，并确定了重要源区的一些地质特征。以来自北非的尘埃传输为例，介绍了可能的远距离尘埃影响，并评估了非洲尘埃对北大西洋西部和美国东南部环境过程的影响。远距离传输的尘埃通常质量中值直径小于10微米。小型风载土壤颗粒显示出广泛风化的迹象；因此，颗粒的物理和化学性质将极大地取决于源区的风化历史以及在大气中传输期间（通常为一周或更长时间）发生的后续变化。为了充分了解尘埃在环境和人类健康中的作用，矿物学家将不得不与其他学科的科学家密切合作，以表征矿物颗粒作为一个整体以及单个颗粒的性质，特别是关于表面特征。
