TRANSFERABILITY EXPERIMENTS FOR ADDRESSING CHALLENGES TO UNDERSTANDING GLOBAL WATER AND ENERGY BUDGETS Eugene S. Takle, Raymond W. Arritt, and William J. Gutowski, Jr. Iowa State University Ames, IA USA Objective of the GHP Transferability Working Group To understand the physical processes underpinning the global water and energy cycles and their predictability through systematic intercomparisons of regional climate simulations on several continents and comparison of these simulated climates with coordinated continental-scale observations and analyses. Modeling Component  What has been learned from past and current MIPs?  What are the impediments and advantages for participation of “non-native” models and centers in international transferability experiments?  Develop a set of modeling issues that will benefit from transferability experiments: * What do we mean by transferability? * What are transferability criteria? * What are the transferability accuracy expectations? * What simulation processes challenge the transferability criteria? * What environments challenge the transferability criteria?  Develop consensus on a hierarchy of transferability numerical simulations. Observations Component  Review what has been learned from past and current continental-scale experiments  Review local unique features critical to accurate simulation of water and energy cycles  Review variables, frequency, and metadata for datasets available or being collected  Examine data accessibility issues and data format compatibility  Review quality and differences of different reanalysis datasets  Search for “meta-comparisons” that might be done by blending intercom- parisons from different continental-scale experiments. PIRCS PRUDENCE LA PLATA RMIP IRI/ARC GKSS/ICTS ARCMIP AMMA Initiation of TWG The 9th Annual Meeting of the GEWEX Hydrometeorology Panel (GHP) proposed organizing transferability experiments to advance the science of regional climate modeling by use of coordinated continental scale observations and analyses. A Transferability Working Group (TWG) has been proposed within GHP. “Percentage of domain in ocean vs. land may influence predictability” TWG operating strategy: Develop a set of hypotheses that will be tested through applications of multiple regional climate models on multiple domains by taking advantage of data sets from coordinated major continental-scale experiments. “Regions of intense hydrological and energy cycles (e.g., tropics) exposes model shortcomings for simulating soil moisture feedbacks.” Thanks to J. Roads, J.-H. Christensen, D. Paquin, C. Jones for comments MAGS BALTEX MDB GAME GAPP LBA GAPP LBA GAME CATCH “Access to many validation datasets reveals model shortcomings” “Percentage of domain in ocean vs. land may influence predictability” “Model applications on multiple domains promotes robust parameterizations” For further information contact or BALTIMOS CAMP GLIMPSE SGMIPQUIRCS