Airborne minerals and related aerosol particles: Effects on climate and the environment

Aerosol particles are ubiquitous in the troposphere and exert an important influence on global climate and the environment. They affect climate through scattering, transmission, and absorption of radiation as well as by acting as nuclei for cloud formation. A significant fraction of the aerosol particle burden consists of minerals, and most of the remainder— whether natural or anthropogenic—consists of materials that can be studied by the same methods as are used for fine-grained minerals. Our emphasis is on the study and character of the individual particles. Sulfate particles are the main cooling agents among aerosols; we found that in the remote oceanic atmosphere a significant fraction is aggregated with soot, a material that can diminish the cooling effect of sulfate. Our results suggest oxidization of SO2 may have occurred on soot surfaces, implying that even in the remote marine troposphere soot provided nuclei for heterogeneous sulfate formation. Sea salt is the dominant aerosol species (by mass) above the oceans. In addition to being important light scatterers and contributors to cloud condensation nuclei, sea-salt particles also provide large surface areas for heterogeneous atmospheric reactions. Minerals comprise the dominant mass fraction of the atmospheric aerosol burden. As all geologists know, they are a highly heterogeneous mixture. However, among atmospheric scientists they are commonly treated as a fairly uniform group, and one whose interaction with radiation is widely assumed to be unpredictable. Given their abundances, large total surface areas, and reactivities, their role in influencing climate will require increased attention as climate models are refined.

Klima und Landschaftsumgestaltung – Palynologische Hinweise zur Komplexität prähistorischer Mensch-Umwelt-Beziehungen

Pollen analytical studies of four radiocarbon dated sediment records from Switzerland suggest distinct phases of forest clearances and intensified land use from 1450–1250 BC, 650–450 BC, 50 BC–100 AD, and around 700 AD. These land use expansions coincided with periods of warm climate as recorded by Alpine dendroclimatic and Greenland oxygen isotope records. Our results suggest that harvest yields increased synchronously over wide areas of central and southern Europe during periods of warm and dry climate. Positive long-term trends in pollen values of Cerealia and Plantago lanceolata indicate that technical innovations during the Bronze and Iron Ages (e.g. metal ploughs, scythes, hay production, fertilizing methods) gradually increased agricultural productivity. However, our data imply that human societies were not able to compensate rapidly for harvest failures when the climate deteriorated. Agriculture in marginal areas was abandoned, and spontaneous reforestations took place on unoccupied land both north and south of the Alps.

Ueber Aristophanes Wolken.

Reprinted from Jahrbücher für classische philologie, 1861, hft. 10.

Klima-Atlas von Deutschland,

Mode of access: Internet.

Klima-Tabeller for Norge.

pt. 1. Luftens temperatur.--pt. 2. Lufttryk.--pt. 3. Luftens fugtighed.--pt. 4. Vind.

Das Klima von Frankfurt am Main; eine Zusammenstellung der wichtigsten meteorologischen Verhältnisse von Frankfurt a.M.

Mode of access: Internet.

Aristophanes' Wolken ; eine komödie, griechisch und deutsch.

Edited by F. A. Wolf. cf. Paris. Bibliothèque national. Catalogue général.