The writing and production of this volume recognize its potential role as a textbook for courses in “Environmental Mineralogy”, a field that calls on both core mineralogical skills and interdisciplinary understanding across chemical, biological and geological fields. It is an area ideally suited the development of advanced teaching that redefines the boundaries of mineralogy, one of the oldest of the sciences. In that context, this volume fulfils a need defined in the Socrates/Erasmus Programme of the European Union. Sponsorship from the EU in the development of a coordinated European curriculum in mineralogy has been important in bringing this project to fruition, and thus in creating materials for European courses in environmental mineralogy, specifically as an Intensive Programme (lP) which falls at the border between Erasmus CDI and CDA levels.
Aerosol particles in the troposphere: A mineralogical introduction
Published:January 01, 2000
The atmosphere of the Earth is a colloidal system that contains liquid and solid aerosol particles beside gas-phase components. Aerosol particles are ubiquitous and play an important role in the physics and chemistry of the atmosphere, especially in the lower 10–15-km layer, the troposphere. Above a turbulent layer that extends from the surface to an altitude of 1–2 km, the troposphere is filled with a homogeneous particle population that constitutes the background aerosol (Junge, 1963).
There is great scientific interest in atmospheric aerosols, stemming from a recognition of their significance in affecting our weather and climate. Aerosol particles change Earth’s heat balance both directly and indirectly. They scatter and absorb solar radiation, thereby modifying the planetary albedo; this is called the direct effect. Aerosol particles may act as cloud condensation nuclei (CCN), thereby modifying the physical and radiative properties of clouds; this is known as the indirect effect (Fig. 1). The term radiative forcing refers to changes in the planetary radiation budget, caused by anthropogenic or external influences; it is measured in watts per square meter (Wm−2), and a positive value means net warming, whereas a negative value indicates net cooling of an air column above the Earth’s surface (IPCC, 1996).
In addition to being agents of climate change, aerosol particles affect our environment in various ways. For example, high concentrations of particles can cause serious visibility degradation; some particle types are notable for their contribution to atmospheric acidity, whereas other types are important because of their health effects.