Research Needs and Directions of Regional Climate Modeling Using WRF and CCSM
In final form 12 September 2006 ©2006 American Meteorological Society limate varies across a wide range of temporal and spatial scales. Yet, climate modeling has long been approached using global models that can resolve only the broader scales of atmospheric processes and their interactions with land, ocean, and sea ice. Clearly, large-scale climate determines the environment for mesoscale and microscale processes that govern the weather and local climate, but, likewise, processes that occur at the regional scale may have significant impacts on the large-scale circulation. Resolving such scale interactions will lead to a muchimproved understanding of how climate both influences and is influenced by human activities. Since October 2003, the National Center for Atmospheric Research (NCAR) has supported an effort to develop regional climate modeling capability using the Weather Research and Forecasting (WRF) model (see information online at www.wrfmodel.org/index.php) and the Community Climate System Model (CCSM) (information online at www. ccsm.ucar.edu/models). The goal is to develop a next-generation community Regional Climate Model (RCM) that can address both downscaling and upscaling issues in climate modeling. Downscaling is the process of deriving regional climate information based on large-scale climate conditions. Both dynamical and statistical downscaling methods have been used to produce regional climate change scenarios; however, their resolution and physical fidelity are considered inadequate. Hence, the global change community has expressed a strong demand for improved regional climate information to explore the implications of adaptation and mitigation and assess climate change impacts (see information online at www.climatescience. gov/events/workshop2002/). Upscaling encapsulates the aggregate effects of small-scale physical and dynamical processes on Research Needs and Directions of Regional Climate Modeling Using WRF and CCSM