Two simulations of the 21st century climate have been carried out using, on the one hand, a coarse resolution climate general circulation model and, on the other hand, the same model coupled to a comprehensive model of the Greenland ice sheet. Both simulations display a gradual global warming up to 2080. In the experiment that includes an interactive ice sheet component, a strong and abrupt weakening of the North Atlantic thermohaline circulation occurs at the end of the 21st century. This feature is triggered by an enhanced freshwater input arising mainly from a partial melting of the Greenland ice sheet. As a consequence of the circulation decline, a marked cooling takes place over eastern Greenland and the northern North Atlantic. This result underlines the potential role of the Greenland ice sheet in the evolution of climate over the 21st century.

ABSTRACT. We present results from a greenhouse warming experiment obtained from an atmosphere^ocean^sea-ice general circulation model that is interactively coupled with a three-dimensional model of the Greenland ice sheet. The experiment covers the period 1970^2099 and is driven by the mid-range Intergovernmental Panel on Climate Change SRESB2 scenario. The Greenland model is a thermomechanical high-resolution (20 km) model coupled with a viscoelastic bedrock model. The melt-and-runoff model is based on the positive degree-day method and includes meltwater retention in the snowpack and the formation of superimposed ice. The atmospheric^oceanic general circulation model (AOGCM) is a coarse-resolution model without flux correction based on the Laboratoire de Me¨te¨orologie Dynamique (Paris) LMD 5.3 atmospheric model coupled with a primitive-equation, free-surface oceanic component incorporating sea ice (coupled large-scale ice^ocean (CLIO)). By 2100, average Greenland annual temperature is found to rise by about 4.5 C and mean precipitation by about 35%. The total fresh-water flux approximately doubles over this period due to increased runoff from the ice sheet and the ice-free land, but the calving rate is found to decrease by 25%. The ice sheet shrinks equivalent to 4 cm of sea-level rise. The contribution from the background evolution is not more than 5% of the total predicted sea-level rise. We did not find significant changes in the patterns of climate change over the North Atlantic region compared with a climate-change run without Greenland fresh-water feedback.

volition, entre motivation et cognition : quelle place dans la pratique des étudiants, quels liens avec la motivation et la cognition? », Revue internationale de pédagogie de l'enseignement supérieur [

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To reflect the importance of network technologies, networking courses are now part of the core materials of Computer Science degrees. We report our experience in jointly developing an open-source ebook for the introductory course, and a series of open educational resources for both the introductory and advanced networking courses. These ensure students actively engage with the course materials, through a hands-on approach; and scale to the larger classrooms and limited teaching staff, by leveraging open-source resources and an automated grading platform to provide feedback. We evaluate the impact of these pedagogical innovations by surveying the students, who indicated that these were helpful for them to master the course materials.