II. NCAR and the Changing Context of Atmospheric Science

The next five years will present significant opportunities and challenges for NCAR and the broader atmospheric and related sciences. Even in the few years since the last NCAR strategic plan, we have witnessed significant advances in our understanding of fundamental atmospheric processes and how the atmosphere interacts with and is influenced by other components of the Earth system. Notable strides have also been made toward understanding the solar processes that affect the Earth's atmosphere and environment in space. The knowledge gained through these efforts has been incorporated in ever-improving research and operational models, thereby yielding further insights and providing better predictions of weather (including catastrophic events), climate variability and change, and space weather. This progress is being driven, in part, by new technologies, including sophisticated remote and in situ instruments and increasingly powerful computers and information systems.

Yet our understanding and ability to predict the Earth and Sun systems remain insufficient for societal needs. Rapidly changing environmental conditions and growing societal need for relevant information and services are placing new demands on the atmospheric and related sciences. For example, human-induced global climate change has been largely accepted as real, but information about temperature changes are not at a sufficiently fine scale for planning regional adaptation and mitigation. Increasingly sophisticated yet remarkably vulnerable societies need greater detail, accuracy, and lead time in weather and space weather forecasts. Air quality remains a major problem, and we are witnessing food and water shortages in many areas. Further scientific progress, active engagement with a range of stakeholders, consideration of societal needs in research planning, and more effective transfer of applications and information to users are needed to effectively address these issues.

• Improved understanding and documentation of many basic processes is needed to better explain relationships and feedbacks among components of the Earth and Sun systems and to develop more accurate predictive models.
• We need weather, climate, and chemistry models that can provide accurate and reliable predictions of regional climate change and air quality, including the statistics of extreme events and high-impact weather. Initializing and validating the high-resolution models needed for this task requires significant advances in observations and data assimilation.
• In order to more accurately predict phenomena like hurricanes and possible changes in their intensity and frequency, models must resolve these phenomena, the critical forcing elements, and the associated planetary-scale circulations in which they are embedded.
• Improvements in modeling and observations are needed to better understand the likelihood of abrupt climate change; the rate and magnitude of sea-level rise; changes in the water cycle; changes in ecosystems; and the effects of climate change, agricultural practices, and other stresses on uptake and release of carbon from the biosphere and oceans.
• Equally imposing difficulties must be surmounted in order to understand the nature and impacts of the solar outputs that connect the Earth and Sun systems.

Atmospheric scientists are crossing disciplinary boundaries to respond to these challenges. Collaborations with oceanographers, biologists, demographers, and economists are necessary to understand and model the causes and impacts of weather and climate change, while work with software and hardware engineers is required for improved use of advanced computers and development of new observing systems. Closer cooperation with social and communication scientists can help to more effectively identify information needs, increase the salience of the natural sciences to decision making, and improve the outcome of decisions through better communication approaches and methodologies. Atmospheric science continues to cross organizational and national boundaries as well. National and international coordination of research is becoming increasingly important, not only because the atmosphere is a global commons but because many problems require scientific and engineering expertise beyond that resident in any single institution, nation, or discipline.

All of these factors have influenced our planning, leading to a strategy that balances and integrates theory, modeling, and observation. It emphasizes fundamental research on the processes that are central to the operation of the Earth and Sun systems; leadership in the development and provision of observing, supercomputing, and modeling facilities; aggressive pursuit of key integrative and collaborative scientific thrusts; a close, synergistic relationship with the university community; extensive national and international collaboration; and development of the human capital needed to achieve these aims. While core disciplines necessarily remain an emphasis, NCAR's programs have become increasingly interdisciplinary in order to address the challenges of studying the atmosphere, terrestrial environment, and Sun as interrelated systems.

Our long-term goal is to build on improvements in scientific understanding, software engineering, and computational technology to develop a next-generation Earth System Model that provides a more complete representation of the Earth system. Such a model would enable analysis of processes across multiple scales and examination of the relationships and feedbacks among multiple environmental stresses. Its development will require more collaboration among weather and climate scientists; new approaches for coupling oceanic, land surface, chemical, biogeochemical and physical processes; and creative methods for including human activities and influences. This long-term objective shapes and guides many of the activities that are described in this document, even though full realization is probably more than a decade away.