HR: 17:00h
AN: A24B-05    [Abstracts]
TI: Concentrations of Aerosol related Particulate Matter and its darkening of Arctic Glacier Ice Surfaces
AU: * Bøggild, C E
EM: carl.egede.boggild@unis.no
AF: Carl Egede Bøggild, University Centre in Svalbard (UNIS) Box 156, Longyearbyen, N-9171, Norway
AU: Hodson, A
EM: A.J.Hodson@sheffield.ac.uk
AF: Andy Hodson, University of Sheffield, Sheffield, S10 2TN, United Kingdom
AU: Mattila, O
EM: olli-pekka.mattila@helsinki.fi
AF: Olli-Pekka Mattila, Department of Physical Sciences, Univ. of Helsinki P.O.Box 64, Helsinki, FIN-00014, Finland
AB: The glacier surface albedo is important for ice melt. Studies have revealed that even small changes in the surface albedo often have significant impact on the resulting ice melt. For instance a 15% reduction in surface reflectance on the Greenland ice sheet is sufficient to cause over one meter annual excess ice melt, which is the magnitude of present thinning may places on the Greenland ice sheet margin. Except for minor areas around Nunataks as well as moraine material the surface the particulate matter (PM) constitutes of aerosols accumulated on the glacier surface for hundreds or thousands of years. In PM on the glacier surface a significant biological activity exists due to abundance of algae, bacteria and other micro- organisms. The biological activity is able to effectively bind particles to the biomass in so-called "cryoconite". The result is a favourable substrate for bacterial activity, which "flocculate" the micro particles and thus affects the glacier surface albedo. Besides biological activity formation of "cryoconite holes" (depressions/holes in the ice filled with concentrated matter) also affects the resulting albedo. The combined effects and interaction between biological activity, material matter and formation of cryoconite holes makes the resulting albedo a complex parameter in the surface energy budget. However, one inherent factor affecting it all is the ice surface mass concentration of PM predominately from aerosols. We here present measured concentrations of PM from three different glacier types and locations in the Arctic - namely the north- eastern Greenland ice sheet margin, the valley glacier Midre Loweenbreen and the Vestfonna ice cap, both on Svalbard.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0360 Radiation: transmission and scattering
DE: 0720 Glaciers
DE: 0792 Contaminants (0432)
DE: 1621 Cryospheric change (0776)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting