Forecast and specification services are supported by four pillars--research, observations, models, and education--and by a process that transitions and integrates knowledge into the operational forecast system.
Improving forecasting and specification services is the end goal of this Program. It is the element that directly addresses national needs in natural disaster reduction, and provides the focus for the other contributing elements. Operational forecasts cover multiple lead-times: minutes to hours (warnings), days, and years (solar cycle forecasts). Dependability of services is essential to users. The products must be available on a regular, recurring basis in standard formats.
Space weather forecasters do a commendable job given the resources at hand. But present forecasts are often not sufficient for customers to take specific mitigation actions or make specific planning decisions. Three measures of useful forecasts are: accuracy, reliability and timeliness. Accuracy means the forecast values closely approximate the subsequently observed condition. Reliability means the conditions that are forecast do, in fact, occur. Timeliness means the customer receives the needed information in time to make decisions or take action. Requirements for forecasts, alerts and warnings are established by the users of these services. Few of the current requirements can be fully met; some can not be met at all.
"Specification" (or nowcasts) refers to the fusion of all available observations into a coherent and realistic representation of the state of the space environment at the time of the observations. Synchronizing and merging the diverse observational data sets pose significant scientific and technical challenges. Sophisticated, physics- based models are needed to fill in areas where there are no observations. Today's space weather models are just starting to approach this goal.
The National Space Weather Program will guide improvements of the capability to process, assimilate, and analyze increasingly complex data sets. Rapid advances in computer technology have opened a realm of possibilities for development of expert systems, image feature recognition, real-time data access, and database systems. Near-real-time data assimilation is also required for initialization and updating of forecasting models.
Space weather services depend on data collection and processing in the same way that tropospheric weather forecasts do. Data need to be collected from a large number of sensors strategically placed on the Earth's surface, in Earth orbit, and in interplanetary space. The forecast centers need computer systems that can rapidly process and analyze large volumes of observational data; run fairly complex models in real-time; display and manipulate imagery; derive, generate, and disseminate useful products; and facilitate data sharing and back-up responsibilities. Acquisition of new data sets and development of advanced models, with complex calculations, will require greatly enhanced computer systems at the core of space weather services. The forecast centers must replace and continually upgrade both hardware and software to deal with the growing computational needs.
Climatological studies and products also need improving to satisfy the need of planners and engineers to know the range of conditions their systems may encounter and the probabilities of those conditions.
New technology will greatly improve the dissemination of space weather information to users of systems affected by the space environment. Space weather products have been limited to simple indices, a few data points, and generalized global forecasts. New models will produce maps, images, specific forecasts, and precise data summaries of disturbances. New standard products will include maps showing the location of intense radiation zones, ionospheric variations that compromise satellite-to-ground communications, and magnetic field variations sufficient to interfere with electric power grid operation. Easy, timely access to the new products will significantly enhance the quality of the information available to forecast users and their ability to safeguard or profitably improve their own operations.
Development of the "information superhighway", the capacity of networks to distribute data- intensive graphics and images rapidly over computer-to-computer links, and the access of thousands of users, civilian and military, to these enhanced communication networks, will be exploited for optimal dissemination of space weather services.
An effective National Space Weather Program requires a strong commitment to basic research in many areas of space-related science. Research is needed to advance state-of-the-art instruments and data gathering techniques, to conduct future space missions, to understand the physical processes, to develop predictive models, to provide systems designers with input on conditions in the space environment, and to perform detailed analysis of data associated with past events that have caused significant impacts to space systems. New and creative experiments, employing present and planned space-based and ground-based sensors, will be required.
Because of the importance of observations in both the development of models and post-event analysis, space weather research will take advantage of data obtained by both scientific and operational instruments and missions. Close cooperation among the agencies that support such instruments and missions will make these data more widely available to the research community. In addition, basic research will be conducted in developing and refining techniques for monitoring the space environment. The Program will enable effective planning, communication, and cooperation between the research and operations communities. This will ensure that the latest advancements in the understanding of physical processes and space sensing techniques are verified and put into operations as quickly as possible, and also that future space missions will effectively contribute to Program goals.
The areas of space research that are relevant to space weather include studies of the sun, the solar wind and interplanetary medium, the magnetosphere, the ionosphere, and the upper atmosphere. In conducting this research, we must emphasize understanding of the coupling of these regimes. An interdisciplinary approach is required, with a strong dependence on merging observations, theory, and modeling. The research goal is to synthesize the scientific phenomenologies into a coherent and unified picture of the coupled sun-Earth system. Research will lead to the development of quantitative prediction models, capable of assimilating data obtained by widely separated and disparate instruments on the ground and in space.
Although it has long been suspected that sporadic geomagnetic disturbances are due to eruptive events on the sun, it is only in the last 20 years that research on the solar corona and interplanetary medium has identified a mechanism by which this could occur. Interactions of high-speed solar wind with the slower ambient flow give rise to compressed regions of plasma. When these reach the magnetosphere they can disturb it significantly, especially if the imbedded interplanetary magnetic field has a large southward component. Coronal mass ejections are a source of non-periodically recurring perturbations in the interplanetary plasma and magnetic field and the resulting effects on Earth's space environment. The propagating plasma disturbances also accelerate energetic particles, which can then be directly injected into the magnetosphere. In addition, the short- wavelength, high-energy radiation emitted from flare sites on the sun, sometimes in association with other eruptive events, reaches Earth in eight minutes, causing almost immediate effects on the current systems in the upper atmosphere.
A focused research goal is thus to understand and predict the timing and location of eruptive solar events, both mass ejections and flares, and to establish whether individual solar events, once observed, are destined to cause disruptions at Earth. To successfully forecast events a day or more in advance, we must have better knowledge as well as better monitoring of the sun and interplanetary medium.
The magnetosphere is determined by the interaction between the Earth's magnetic field and the solar wind. The solar wind drives processes that couple large regions of space both magnetically and electrically. The outer boundary of the Earth's magnetosphere forms a barrier that prevents large amounts of energy, particles, and momentum carried by the solar wind from entering the magnetosphere. This barrier is not impenetrable. By a sequence of complex processes that are still incompletely understood, part of the solar wind's particle and energy content penetrates into the Earth's space environment. Strong electric fields and currents are generated and induced within the magnetosphere, the ionosphere, and the Earth's surface.
Our present knowledge of the magnetospheric phenomena basic to space weather prediction and forecasting is quite rudimentary. Models exist, but they often rely on many free parameters that can be adjusted somewhat arbitrarily. Simulations need to be three-dimensional, cover an immense volume, and include processes occurring over multiple scale sizes. Progress will depend on improved understanding of the following: (1) transfer of energy from the solar wind to the magnetosphere; (2) generation, time dependence, and relative strength of the electric current system; (3) generation and distribution of energetic particles in the magnetosphere; (4) processes by which the magnetosphere abruptly releases energy into electric currents and energetic particles; (5) time dependence of the impulsive heating of the upper atmosphere and the redistribution of this energy; and (6) auroral electrojets.
An artist's conception of the magnetosphere showing magnetic field lines that connect to the aurora in the Earth's polar region.
Dana Berry/(c) The Walt Disney Co. Reprinted courtesy of the artist and Discover Magazine
The ionosphere and neutral atmosphere are important to space weather, not only because they are regions where adverse effects commonly occur, but also because they are strongly coupled to each other and to other regions of space. Both the ionosphere and neutral atmosphere vary significantly in response to changing solar energy input on time scales of days to years. Understanding the dynamics of the neutral atmosphere is critical to the development of models that adequately account for many effects, including low-orbit satellite drag. Ionospheric researchers are developing the capability to predict the behavior of variations that affect the propagation of radio waves, with widespread applications. Still incompletely understood is the way in which the ionosphere and atmosphere respond to magnetic storms. These storms provide a large, sudden, impulsive input of energy into the top of the ionosphere in the forms of energetic particles and electrical currents. Research in these areas must encompass the physical processes that govern the regions as well as the development of techniques for remotely monitoring atmospheric properties.
A picture of the aurora as detected by an imaging instrument on the Dynamics Explorer Satellite.
An important exception to the "trail of energy flow" from the sun to Earth is the type of severe ionospheric disturbance that occurs at night near Earth's magnetic equator. Here, the intensity of disruption of communication and navigation systems is the most severe on the planet. The triggering of these disturbances is an open area of active research, but it is clear that the onset mechanism, which is fairly well understood, is largely independent of processes going on in the magnetosphere.
Users of space weather information are concerned with both the background environment and the time of arrival, intensity, and duration of space weather disturbances as they manifest themselves at specific locations. The variations occur on time scales from minutes through days to years. To have a complete picture of the environment from the present into the future, forecasters need observations from key locations beginning with the origin of the disturbances at the sun and continuing along their propagation routes into the near-Earth environment.
Today, space weather forecasting is in a situation similar to that of weather forecasting half a century ago. Even with the present and planned instruments, the data are sometimes too sparse, and some critical data, such as in-situ solar wind parameters, are not available at all. The gaps in our ground-based observations are particularly acute at very high latitudes, where the magnetic field maps out to the distant regions of the magnetosphere. New ground- and space-based instruments, coupled with quantitative modeling, will provide an enormous improvement in space weather specification and forecasting quality.
An adequate suite of data sources must be established, expanding on the current networks and exploiting new sensors evolving out of research programs. The networks must be global, with dense enough coverage to provide regional specifications, and include real-time or near-real-time communications. An exciting prospect is to proceed from current methods of in-situ measurements to an imaging capability of vast three-dimensional volumes of nearby space. The data must also provide the right input to optimize the use of models and support accurate climatologies for system designers. A key benefit of the National Space Weather Program will be to evaluate observational needs and guide the most cost- effective solutions.
Physics-based, quantitative models are required to provide a predictive capability not presently available. The new models will replace the limited heuristic algorithms, statistical relationships, and human estimates used today in space weather forecasting and engineering design systems. The US Air Force (USAF) has procured a first generation of space weather models. Initial specification models will allow the use of current observations to represent conditions at different locations in near-Earth space; forecast capabilities will be added as soon as possible.
Model results showing the predicted distribution of energetic electrons in the magnetosphere. Surface charging anomalies experienced by two geosynchronous satellites occurred in the region between midnight and dawn.
The major elements of this effort are incorporation of scientific results into research models, the transfer into operational models, the validation and testing of models, the implementation of the models into operations, and the improvement of forecast services. The NSF, NASA, and DOD (USAF and US Navy) conduct research to incorporate new understanding of the solar-terrestrial environment into research and development models. DOD and NOAA have joint responsibility for transitioning the improved models into operations. Research models must be tailored to meet operational needs. Models must be integrated with each other and with empirical forecast techniques into a system that provides the best possible answer to the forecaster's question. The system must have a user-friendly interface, be easy to upgrade, and run on a variety of hardware.
Educational opportunities in space weather apply to engineers, operational forecasters, students, and the general public. Space weather forecasting can both educate and excite students worldwide. To further national science and mathematics education goals, the Program will encourage efforts to make space weather an important element of science curricula in grade schools, secondary schools, and college. Improved methods for disseminating space weather data will allow students to witness space phenomena in a classroom setting. They will be able to see real-time displays of variable solar radiation, solar eruptions, the impact of energetic particles on Earth, auroral events, ionospheric currents, and other unique phenomena. Students could use data to make their own space weather forecasts and warnings, while considering the practical aspects of cost versus benefits.
Educational activities supported under the National Space Weather Program will heighten public awareness of the impact of space weather on human activities. It is conceivable that future space weather reports will become a regular feature of nightly news broadcasts. Efforts in this area have already been undertaken at the university level. Growing media exposure will foster an appreciation for the dynamic space environment in which the Earth is encompassed and will help to foster a scientifically literate citizenry.
In the operational arena are space weather observers and forecasters, military weather personnel supporting communications and space launch operations, space operations controllers, satellite designers and engineers--all requiring some form of education to improve their performance. Training courses using modern media capabilities are needed to meet the gamut of applications, from in-depth, resident courses, to portable, self-taught modular courses. Improved user and operator awareness will increase the effectiveness of space weather support and will produce better feedback to help focus further improvements.
A coordinated program for technology transition is a key building block of the National Space Weather Program. Agencies will expand the ways in which they work together to determine requirements and set priorities for implementation of new technologies based on ongoing research and development work. Each agency will contribute its respective expertise to a streamlined technology transfer process that emphasizes the transition from new observations and improved scientific understanding into the development of improved scientific models; the conversion of those improved models, sensors, and insight into operational versions; the testing and validation of the operational versions; and their implementation into space weather services. Trade-offs, reprioritization, major changes in observing systems, and shifts in operational responsibility will be coordinated more closely among participating agencies.
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