HR: 15:10h
AN: B43H-07    [Abstracts]
TI: Coupling of a GCM of Intermediate Complexity and a Dynamic Vegetation Model Including Interactions With Land Use
AU: * Strengers, B
EM: bart.strengers@mnp.nl
AF: Netherlands Environmental Assessment Agency, A. van Leeuwenhoeklaan 9, Bilthoven, 3721MA, Netherlands
AU: Schaeffer, M
EM: michiel.schaeffer@wur.nl
AB: IMAGE is an ecological-environmental framework that simulates the environmental consequences of human activities worldwide. It represents interactions between society (including land use), the biosphere and the climate system to assess sustainability issues like climate change, food security and human well-being. Currently the climate-carbon-vegetation system is modelled in a rather simple way. For example, IMAGE includes a simple climate model and translates long-term trends in surface temperature to climate changes on the gridlevel using output patterns from state-of-the-art GCMs. IMAGE has been used in many studies and has shown to be very useful, but does not allow investigating more regional aspects of climate change and feedbacks between climate and land cover including land-use change. Therefore, IMAGE has been extended by the GCM of intermediate complexity SPEEDY coupled to the dynamic global vegetation model (DGVM) LPJ. This allows for investigating the "hot spots"in the interactions between vegetation, climate, carbon and land use for different scenarios and to analyze the types of dependencies (linear, discontinuities, tipping points). It requires frequent adaptations of model characteristics and many ensemble members which is not possible with complex GCMs because of computational limitations. Currently, a simple link between SPEEDY/LPJ and IMAGE has been established, in which the IMAGE output of a scenario run in terms of land-use change is used to drive SPEEDY/LPJ. A full coupling in terms of land use change decisions being affected by the output from SPEEDY/LPJ will be established later. The conceptual background will be presented, followed by first results showing that vegetation and climate patterns generated by the coupled SPEEDY/LPJ framework agree reasonably well with observations. In summer SPEEDY/LPJ generate temperature patterns that are in reasonable agreement with observations, also considering the performance of state-of-the-art GCMs of the same resolution. In winter, there are larger deviations between predicted and observed temperature in northern hemisphere climates (Central Asia and eastern Canada).
DE: 0402 Agricultural systems
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0429 Climate dynamics (1620)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting