The aim of drilling ice cores is to obtain paleoatmospheric information of wide significance. However, the concentrations of chemicals found in the- ice are determined both by the atmospheric concentrations, and by depositional and post-depositional processes. Other papers in this volume discuss the depositional processes, ami the processes that subsequently alter the concentrations in near-surface (up to a metre or so depth) snow. However, there arc a number of documented cases where further changes occur below the surf act snow. Additionally, there is the possibility that chemical changes can occur, at least to more complex species, over tlx: long timescales that arc relevant for ice. Diffusion is bound to take place to some extent, affecting the apparent rate of temporal change inferred from ice core profiles. Discussion of all the factors requires an understanding of the way in which impurities are held in the ice This paper discusses all these items, conccntrating on processes in solid ice. and in firm below the top metre or two.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- Location, Movement and Reactions of Impurities in Solid Ice
Eric W. Wolff
- Springer Berlin Heidelberg