HR: 09:00h
AN: C31A-05    [Abstracts]
TI: Exploring the Effectiveness of Alpine Permafrost Model Transfer Between Mountain Environments in Northwestern Canada
AU: * Bonnaventure, P P
EM: pbonn075@uottawa.ca
AF: University of Ottawa Department of Geography, 60 University, Ottawa, ON K1N 6N5, Canada
AU: Lewkowicz, A G
EM: alewkowi@uottawa.ca
AF: University of Ottawa Department of Geography, 60 University, Ottawa, ON K1N 6N5, Canada
AB: The BTS method developed by Haeberli (1973) has been used extensively to model mountain permafrost distribution in Europe, Asia and most recently in North America. The method involves recording the mid-winter temperature beneath a deep (>80 cm) snow pack in a variety of mountain locations as an indicator of the presence or absence of permafrost. The BTS results can then be related statistically to factors such as elevation and Potential Incoming Solar Radiation (PISR) which contribute to the existence of mountain permafrost. This empirical statistical methodology can be used to generate detailed permafrost predictions within a GIS using limited field information. When combined with binary permafrost ground-truthing undertaken in the late-summer months probability models can be generated using logistic regression. Although this methodology provides far more detailed information on permafrost occurrence than traditional permafrost maps one of the major drawbacks is that models are highly localized and thus require re-sampling from area to area. A potential reason for this is that mountain ranges in north-western Canada are often climatologically dissimilar with the development of permafrost occurring due to a variety of factors including elevation, regional climate, local snow depths, vegetation and substrate. This study explores how effectively a model created for one area can predict the occurrence of mountain permafrost in other locations both geographically and climatologically similar and dissimilar. Analyses demonstrate that similar patterns of mountain permafrost probability can be generated for areas with similar climate even if they are geographically distant. In climatologically dissimilar areas, however, the predicted spatial distribution of permafrost is not preserved as the weighting of the predictor variables differs significantly. Nevertheless, the total amount of permafrost predicted varies little and this appears to reflect the importance of the ground-truthing data. Trends between areas will be of great importance in future attempts to model discontinuous permafrost distribution in detail for the southern half of the Yukon Territory, Canada, an area of about 0.25 million square kilometers.
DE: 0700 CRYOSPHERE (4540)
DE: 0702 Permafrost (0475)
DE: 0772 Distribution
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting