HR: 0830h
AN: C21B-0815    [PDF]
TI: The Evaluation of Permafrost Dynamics within the Circumpolar Region in 21st Century.
AU: * Sazonova, T
EM: ftts1@uaf.edu
AF: Geophysical Institute, University of Alaska, Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320 United States
AU: Romanovsky, V
EM: ffver@uaf.edu
AF: Geophysical Institute, University of Alaska, Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320 United States
AB: Permafrost is one of the main factors controlling ecosystems health and stability in circumpolar region. With the possibility of climate change in the nearest future permafrost dynamics should be evaluated to estimate the possible effect of those changes on infrastructures, and carbon and hydrological cycles. Existing models for the evaluation of permafrost dynamics over large regions can only be used as rough approximations due to poor spatial resolution. That is why in our studies we used a physically based spatially distributed analytical thermal model (the GIPL model), developed at the Geophysical Institute Permafrost Lab specifically for regional scale investigations of the ground temperature regime and active layer thickness dynamics. In addition to, climate forcing from the high resolution Regional Climate Model (HIRHAM4) was used as upper boundary condition. Two scenarios of climate change (A2 and B2) have been applied. The GIPL model was further improved by incorporating fires effects. This includes major changes in ecosystems after the fire (forest with moss cover transforms into steppe-like ecosystems). There is still the possibly that the forest will recover over the period of 40 - 60 years if the fire severity was low. Due to the lack of the forest fire statistics for the entire circumpolar region, the effect of forest fires was only applied to the Alaskan and East-Siberian transects. The results of the modeling include circumpolar maps of the active layer thickness and mean annual ground temperatures for several temporal intervals within the 21st century. Depending on the climate change scenario, the projective increase in mean annual ground temperatures will range from 2 to 6§C, in active layer thickness is up to 1 m, and will be most pronounced in southern parts of the domain. During the current century, permafrost degradation will start in the southern parts of the circumpolar region and will progress northward. The results of this modeling can be used by scientific communities for the forecast of ecosystems response and infrastructure stability in the 21st century on global and regional scales.
DE: 0400 Biogeosciences
SC: Cryosphere [C]
MN: 2003 Fall Meeting