Learn More
Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation(More)
Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. We have used a terrestrial ecosystem model that includes permafrost carbon dynamics, inhibition of respiration in frozen soil layers, vertical mixing of soil carbon from surface to(More)
During the last glaciation, a marine ice sheet repeatedly appeared in Eurasia. The floating part of this ice sheet was essential to its rapid extension over the seas. During the earliest stage (90 kyr BP), large ice-dammed lakes formed south of the ice sheet. These lakes are believed to have cooled the climate at the margin of the ice. Using 5 an ice sheet(More)
Large proglacial lakes cool regional summer climate because of their large heat capacity, and have been shown to modify precipitation through mesoscale atmospheric feedbacks, as in the case of Lake Agassiz. Several large ice-dammed lakes, with a combined area twice that of the Caspian Sea, were formed in northern Eurasia about 90,000 years ago, during the(More)
The Last Glacial Maximum has been one of the first foci of the Paleoclimate Modelling Intercomparison Project (PMIP). During its first phase, the results of 17 atmosphere general circulation models were compared to pa-leoclimate reconstructions. One of the largest discrepancies in the simulations was the systematic underestimation, by at least 10 • C, of(More)
We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal(More)
Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. Abstract. We use the BISICLES adaptive mesh ice sheet model to carry out one, two, and three century simulations of(More)
Soil freezing is a major feature of boreal regions with substantial impact on climate. The present paper describes the implementation of the thermal and hydrological effects of soil freezing in the land surface model OR-CHIDEE, which includes a physical description of continental hydrology. The new soil freezing scheme is evaluated against analytical(More)
A warming climate is altering land-atmosphere exchanges of carbon, with a potential for increased vegetation productivity as well as the mobilization of permafrost soil carbon stores. Here we investigate land-atmosphere carbon dioxide (CO 2) cycling through analysis of net ecosystem productivity (NEP) and its component fluxes of gross primary productivity(More)