Atmospheric Chemistry and Physics Discussions The transport history of two Saharan dust events archived in an Alpine ice core

• Main Authors: H. Sodemann, A. S. Palmer, C. Schwierz, M. Schwikowski, H. Wernli
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: ice core
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.133.5249; http://www.atmos-chem-phys-discuss.net/5/7497/2005/acpd-5-7497-2005-print.pdf

7497 Mineral dust from the Saharan desert can be transported across the Mediterranean towards the Alpine region several times a year. Occasionally, the dust is deposited with snowfall on Alpine glaciers and appears then as yellow or red layers in ice cores. Two such significant dust events were identified in an ice core drilled at the high-accumulation site Piz Zupó in the Swiss Alps (46 ◦ 22 ′ N, 9 ◦ 55 ′ E, 3850 m a.s.l.). From stable oxygen isotopes and major ion concentrations, the events were approximately dated as October and March 2000. In order to link the dust record in the ice core to the meteorological situation that led to the dust events, a novel methodology based on back-trajectory analysis was developed. It allowed for the identification of source regions, the atmospheric transport pathways, and wet deposition periods for both dust events. Furthermore, differences in the chemical signature of the two dust events could be interpreted with respect to contributions from the dust sources and aerosol scavenging during the transport.