Workpackages
WP 1: Intercomparison and Improvements of atmospheric RCM's
will carry out intercomparisons of three different Arctic regional atmospheric models on the basis of annual simulations of the SHEBA year October 1997-October 1998. The influence of horizontal resolutions (50 km, 25 km and 10 km), of the domain (whole Arctic Basin and the smaller SHEBA subdomain), of physical parameterizations (main focus: planetary boundary layer schemes, land-surface models, cloud-radiation and ice-albedo-water vapour feedbacks, uncoupled-coupled models) will be investigated. Improved schemes for the parameterization of land-surface schemes, planetary boundary layer, cloud schemes and permafrost schemes over land points will be implemented. The new schemes will be validated against observational data. Initial and boundary conditions to drive the model simulations are provided as perfect boundary conditions from observations (ECMWF and NCEP). A serious problem in assessing the performance of simulated regional climate is the availability of good quality high-resolution data for the model validation. Decadal simulations will be carried out to understand natural variability.
WP 2: Intercomparison and Improvements of coupled A-I-O RCM's
will carry out intercomparisons of three different coupled regional models of the atmosphere-ocean-ice system. Coupled atmosphere-ice-ocean models will be developed, integrated and validated for theSHEBA year. Series of 10 year integrations with coupled RCM's will be conducted to understand the atmosphere-ice-ocean feedbacks on the variability of the atmospheric circulation. Such a multifaceted approach is necessary to tackle the complex Arctic climate problems.
WP 3: Comparison of Arctic patterns and climate feedbacks in AOGCM's and RCM's
will compare the annual cycle in atmospheric and oceanic key processes and variables with a special focus on the hydrological cycle and water vapour feedbacks. Series of 50 year long simulations of present day climate with two AOGCM's will be used for this intercomparison.
WP 4: Global consequences of improved description of Arctic climate processes and feedbacks in free AOGCM runs
will estimate the implications and global consequences of the improved physical Arctic process parameterizations and feedbacks in two coupled AOGCM's by carrying out 500 year free simulations with constant external forcing parameters. This allows to determine abrupt changes as a result of multiple equilibria in the unforced climate system as e. g. the two states of the thermohaline circulation under the influence of atmospheric and sea-ice feedbacks.
WP 5: Implications of improved Arctic process description on rapid paleoclimatic changes in forced AOGCM runs
will quantify objectively the risk of abrupt changes in the European climate and climate extremes following natural and anthropogenically forced climate changes by carrying out 500 year long simulations with a coupled climate model under the influence of aerosol, solar and carbon dioxide forcing since 1500 BP.
WP 6: Regionalassessment of Arctic paleoclimatic and future change
will carry out a dynamical downscaling with regional climate models using the paleoclimatic time slices of the AOGCM simulations carried out in WP5, to assess the potential effect of e.g. a rapid shift similar to the Little Ice Age on the economical and socio systems in Europe and the European Arctic.
WP 7: Management, data, reporting and dissemination
is designed to ensure a proper management of GLIMPSE together with the widespread dissemination of GLIMPSE's results, in a usable form to a wide range of users including those outside the project partners. Gridded data sets derived form the global and regional climate model simulations performed in GLIMPSE will be made free available to the climate community and climate impact researchers.