processes that are elements of these connections. Coupling within the AIM system and with other elements in the Sun-Earth system spans timescales from seconds to centuries and serves to refocus efforts in understanding global change and the role of solar variability in climate. Tackling planetary change and space climate issues is dependent on the availability of historical data sets and continuity in observations of key AIM parameters like atmospheric temperatures, composition and cooling rates, and solar inputs like spectral irradiance and interplanetary magnetic field. Finally, the future of assimilative modeling in space weather prediction rests on a continuing supply of near-real-time observations of the AIM system that provide information on large-scale features like the auroral zone and equatorial electrojet as well as small-scale gradients relevant to the triggering of ionospheric instabilities.
Advances in computer power and speed have reached the point that self-consistent simulations of multiscale coupling in the AIM system are already possible. Existing peta-scale computers have reached 300,000 cores, and powerful mega-core computers are expected in the next decade to provide the computational equivalent of 1 million to 10 million CPU cores. These computational advances will drive a revolution in the realism of simulations and the ability to reproduce the self-consistent global signatures of small-scale processes. These advances in modeling in a very real sense parallel the innovations in observational programs that are high-priority targets in this chapter. An investment in a range of technological capabilities is needed to take full advantage of these powerful computational resources, including new multiscale, multiphysics algorithms (such as adaptive mesh refinement), computational frameworks that couple physics across disparate time and spatial scales, innovative ways to mine, visualize, and analyze massive amounts of data produced by the next generation of multiscale simulations, and data assimilation technologies essential to improve space weather forecasting tools.
These requirements and technological advances compel the following:
AIMI Priority: Establish a re-balanced and expanded Research and Analysis Program with the following elements:
• Solar and space physics (heliophysics) science centers, a new program of interdisciplinary centers (heliophysics scientists with computational experts) that leverages the power of peta-scale computers to create powerful physics-based multiscale models of the AIM system and its coupling to other regions, alongside parallel efforts in data assimilation and data fusion. Similar interdisciplinary theory and modeling efforts in the range of $1.5 million to $5 million per year over 3 to 5 years’ duration but not focused specifically on geospace are funded through NSF through its Frontiers in Earth System Dynamics, and AFOSR through its Multidisciplinary Research Program of the University Research Initiative program. NASA funds smaller-scale modeling efforts within the strategic capabilities category in the Living with a Star Targeted Research and Technology program. Given the large costs of these programs, it may work best if NASA, NSF, and AFOSR coordinate their funding of these multidisciplinary programs in order to avoid duplication and ensure that essential projects are funded.
• A strengthened NASA theory program that supports critical-mass groups responding to new theoretical challenges in AIM science using a wide variety of research approaches.
• An enhanced data analysis program (attached to satellite missions and ground-based facilities) that provides a level of support needed to convert new and archived AIM observations into knowledge and understanding.
• An upgraded R&A program that is a reasonable fraction of the overall AIM budget to make sure that expenditures in the program are converted to major advances in science.