Over the past decade, UDPG personnel have been funded by the U.S. National Science Foundation for field studies of active-layer dynamics in northern Alaska. We have also received funding for simulation and synthesis work on the active layer at the circumpolar scale. Field investigations in Alaska were performed in conjunction with the FLUX, ITEX and ATLAS projects. Our work in this regard involved producing spatial time series of active-layer thickness at various geographic scales. Simulations of increases in thaw depth involving general circulation models (Anisimov et al., 1997) and stochastic modeling (Shiklomanov, 2001; Anisimov et al., 2002) form another research emphasis. UDPG is also one of the primary players in the CALM (Circumpolar Active Layer Monitoring) program, a comprehensive monitoring network operating in both hemispheres with close links to several international global-change programs. One of our current field project's emphases involves the variability of near-surface ground thermal regimes in representative land-cover units of the Kuparuk River basin. Much of our work on the active layer in northern Alaska is done in close collaboration with Professor K. M. Hinkel (University of Cincinnati).