Schneebeli Martin
Structure-chemistry interaction during snow metamorphism
Project Number: 200020_125179
| Project Type: |
Research_Project |
| Project Duration: |
05/01/2009 - 04/30/2012 |
| Funding Source: |
SNSF , |
| Project Leader: |
Dr. Martin Schneebeli
Institut für Schnee- und Lawinenforschung, SLF
WSL
Flüelastrasse 11
7260 Davos Dorf
Phone: +41 (0) 81 417 01 11 ; +41 (0) 81 417 01 11
FAX: +41 (0) 81 417 01 10
e-Mail: schneebeli(at)slf.ch
http://www.slf.ch/ |
Research Areas:
| |
|---|
| Cryosphere (Processes) |
| Arctic |
| Antarctic |
| High Altitude |
Disciplines:
| |
|---|
| other areas of earth sciences |
Keywords:
snow physics, snow chemistry, grain boundaries, atmospheric chemistry, snow metamorphism, snow, grain-boundaries, microstructure, chemical processes, nitrous acid
Abstract:
Snow covers a significant fraction of the land mass on Earth. Trace gases exchange between the snowpack and the air mass above it, and they are processed within it. Understanding the partitioning behaviour of trace species in snow helps assessing the impact of the chemical processes in snow on atmospheric composition, on the local environment, and on the relation between atmospheric composition and the composition of ice core archives used to reconstruct past climates. Snow is a highly dynamic medium that undergoes continuous metamorphism dominated by always present and changing temperature gradients, i.e., locally ice is always either growing or evaporating. The structure of snow, its metamorphism and the dynamics of trace gas exchange are a strongly interlinked system with different feedback loops. Trace gas exchange is the consequence of competing processes at the ice surface. On short time scales, gas-ice exchange equilibriums are affected by growth or evaporation of ice, which establishes the water mass flux, while on longer time scales, driven by this water mass flux, the spatial redistribution of ice surfaces and grain boundaries may change the gas - ice interaction as well. We have developed the hypothesis that not only the surface but also the grain boundary surface is mediating structure-chemistry interactions. Grain boundaries are supposed to be important for snow mechanics and snow chemistry, but no quantitative work in this respect is known to us. In this project, we therefore would like to include grain boundary surface (GBS) as an additional structural parameters to determine relations between GBS and specific surface area (SSA), and how GBS is evolving during metamorphism. For both, snow with high and low GBS, we would like to understand, which chemical properties of trace gases determine the degree of surface adsorption and bulk uptake.
Source of Information: NF Import 2009 (30.04.2009)
Last update: 4/24/17
Source of data: ProClim- Research InfoSystem (1993-2024)
Update the data of project: CH-200020_125179
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