Title Polar climate modelling; regional feedbacks and global links, an IPY approach
Author Dethloff, K.; Rinke, A.; Handorf, D.; Dorn, W.; Brand, S.; Läuter, M.; Saha, S.K.; Sokolova, E.; Glushak, K.
Author Affil Dethloff, K., Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Potsdam, Federal Republic of Germany
Source Polarforschung, 78(1-2), p.29-51, . Publisher: Alfred-Wegener-Institut für Polar- und Meeresforschung and Deutschen Gesellschaft für Polarforschung, Bremerhaven, Federal Republic of Germany. ISSN: 0032- 2490
Publication Date 2009
Notes In English with German summary. 87 refs. Ant. Acc. No: 87260. CRREL Acc. No: 64001460
Index Terms air water interactions; albedo; atmospheric circulation; atmospheric pressure; climate; climatic change; computer applications; ice; ice cover; ozone; polar regions; Antarctica; Arctic Ocean; Arctic region; polar regions; air-water interface; Arctic Oscillation; climate change; concentration; data processing; digital simulation; general circulation models; International Polar Year 2007-08; IPY 2007-08 Education, Outreach and Communication Publications; numerical models; sea ice
Abstract Global climate models (GCMs) constitute the primary tool for capturing the behaviour of the Earth's climate system. Regional climate model (RCM) systems with high spatial and temporal resolution and improved physics in polar regions are more accurate than GCMs with relatively low resolution. RCMs can provide added value at small scales to the climate statistics when driven by GCM outputs at the lateral and lower boundaries, assuming that GCMs are accurate on large scales. Any advances in regional climate modelling must be based on analysis of physical processes in comparison with observations, which is rather difficult in data sparse areas like the polar regions, where RCMs are often used as intelligent data interpolator. RCMs can be used as a testbed for the development of improved and more adequate parameterization of important sub- grid scale processes, for the reduction of shortcomings of the used numerical methods, for the choice of the horizontal and vertical resolution, for the quantification of uncertainties in the boundary forcing connected with low-frequency variability in the driving data, for the treatment of the boundary forcing, for the choice of the regional model domain with size and position, for the nesting hierarchy, for the study of internal model variability and for the choice of climate change scenarios. In this way, RCMs can deliver valuable input for improving the performance of global climate models, especially in the Arctic. The use of an ensemble approach of different models with standardised conditions is an accepted model set-up for studying different model realisations of the same climate conditions and for analysing the uncertainty ranges. Uncertainty ranges derived in this manner could be of great importance for the reliability and robustness of regional climate change scenarios for the Arctic. The influences of atmosphere-ocean-sea-ice and atmosphere-land-soil interactions in coupled RCM simulations driven either by European reanalyses (ERA-40) or GCM boundary forcing data have been investigated. These deliver valuable information by improving the physical realism of the considered feedback processes and for quantifying the uncertainty range of Arctic RCM simulations with respect to tuned parameters. The global impact of an improved sea ice albedo parameterization, tested in a RCM setup, and the global influences of interactive stratospheric chemistry in the Arctic polar vortex have been investigated. The need for new dynamical model cores with two-way feedbacks is discussed.
Publication Type journal article
Record ID 296287