Prediction Across Scales
The Prediction Across Scales initiative is a collaborative effort between CGD and MMM to coordinate research and system development activities across weather and climate scales. Recent major advances in petascale computing coupled with rapid advances in scientific understanding are enabling progress in simulating a wide range of physical and dynamical phenomena with associated physical, biological and chemical feedbacks that collectively cross the traditional weather-climate divide. Such simulations and predictions are essential to a society that is becoming much more sophisticated in its requirements for weather, air quality and climate predictions and that is able to make useful economic and social use of such improvements. Moreover, fundamental barriers to advancing such prediction on time scales from days to years, as well as long-standing systematic errors in weather and climate models, are partly attributable to our limited understanding and capability to simulate the complex, multiscale interactions intrinsic to atmospheric and oceanic fluid motions. The scientific and societal questions and issues to be addressed are many. A limited sample includes better understanding of
- The water cycle and its predictability, particularly the limitations of available water and the impacts on food production;
- The limits of weather, air quality and climate predictability including the impacts of mega-cities and the stressed Earth's capacity to sustain quality of life;
- The interaction of hydrological, chemical and biogeochemical cycles and their feedback on weather/climate processes;
- The mechanisms by which solar variations influence the chemistry and dynamics of the upper atmosphere, and how these effects are manifested in the lower atmosphere;
- The interactions between climate change, ENSO and other natural modes of variability, including changes to the behavior of phenomena like hurricanes; and
- The mechanisms of abrupt climate change and potential tipping points.
The enabling tool for much of this research will be a community Nested Regional Climate Model (NRCM). The result of this ambitious effort to combine high resolution regional atmosphere and ocean models with a state-of-the-science climate model will be fundamental progress on the understanding and prediction of regional climate variability and change. In particular, embedding Advanced Research WRF (ARW) and a Regional Ocean Model System (ROMS) within CCSM will allow scientists to resolve processes that occur at the regional scale, as well as the influence of those processes on the large-scale climate, thereby improving the fidelity of climate change simulations and their utility for local and regional planning.