Space Weather Products Research Articles

Renewed Support Dawns in Europe: An Action to Develop Space Weather Products and Services

The effects of space weather span a range of sectors. They can cause radio communications problems; can disrupt synthetic aperture radar systems, the Global Positioning System (GPS), and the future European Galileo systems; and can increase radiation risks for aircraft crew and passengers. Electric power network disturbances and enhanced corrosion effects observed in long-distance fuel supply pipelines are other well-known effects of unfavorable space weather. In severe cases, large-scale power outages have also been traced to space weather phenomena (Figure 1). Research efforts in various countries—including the U.S. multiagency National Space Weather Program (http:// www.nswp.gov), the International Space Environment Service (ISES; http://www.ises-spaceweather.org/), and several European initiatives sponsored by the European Space Agency (ESA) and the European Commission (EC)—have demonstrated that adverse space weather poses a tangible threat to humans and modern technological systems and assets on the ground, in the air, and in space. Although methods to model some aspects of space weather have been developed by these agencies, all agree that their performance needs to be improved—in many cases, prediction accuracy is inadequate to allow the transition from models to reliable operational services. Further targeted research and development is needed. Funding for coordinated space weather science and applications effects in Europe has so far been on a project-by-project basis. Systematic national contributions to a pan-European space weather program are not yet in place, leading to fragmentation of European space weather initiatives. A certain level of

Industry and Government Officials Meet for Space Weather Summit

Commercial airlines, electric power grids, cell phones, handheld Global Positioning Systems: Although the Sun is less active due to solar minimum, the number and types of situations and technologies that can benefit from up-to-date space weather information are growing. To address this, the second annual summit of the Commercial Space Weather Interest Group (CSWIG) and the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) was held on 1 May 2008 during Space Weather Workshop (SWW), in Boulder, Colo. The meeting began with a summary by Thomas Bogdan, director of SWPC, on the progress made on action items from the first annual summit, held in June 2007 (see Space Weather, 5, S10002, doi:10.1029/2007SW000348, 2007). Discussions that ensued related to the continued lack of available sources for solar and other data, the lack of a planned follow-on for the Advanced Composition Explorer (ACE) spacecraft, and the lack of space weather instrumentation on the National Polar-orbiting Operational Environmental Satellite System (NPOESS). CSWIG was especially concerned with the continued lack of knowledge of current SWPC priorities and plans for space weather products. John Kappenman (Metatech Corporation), chair of CSWIG, referred the attendees to the 2006 Report of the Assessment Committee for the National Space Weather Program (http://www.nswp.gov/nswp _acreport0706.pdf), which recommended better coordination between National Space Weather Program (NSWP) agencies and the private sector. Bogdan discussed the status of a planned dedicated server for commercial access, as requested by CSWIG at last year’s summit. Bogdan summarized the challenges facing SWPC, including the lack of availability of key space weather data sets. He anticipates that SWPC will not include some space weather data and products in its core priorities. In light of this, Bogdan said that CSWIG members may be interested in generating for the public the products that SWPC will no longer supply, underscoring that he viewed CSWIG and SWPC as existing in a very important partnership. CSWIG members voiced concerns about the need for advance knowledge of SWPC core priorities so that when CSWIG members develop business plans, the companies do not unintentionally invest in areas where SWPC also plans to commit resources. Mark Gunzelman, then at the Office of the Federal Coordinator of Meteorology (OFCM), which oversees NSWP, spoke about responses to the 2006 Assessment Report and the intent of OFCM to allow the commercial space weather community to actively participate in deliberations of the NSWP Committee. It may be possible to include several members of CSWIG as official representatives and/or technical consultants. Devrie Intriligator (Carmel Research Center) organized and moderated a roundtable session at SWW on behalf of CSWIG. The session’s success in raising appreciation for important space weather issues and the contributions of the commercial sector led Bogdan to announce that such CSWIG roundtables would become permanent features of future SWWs. Summit participants agreed that continued dialogue between CSWIG and SWPC was essential for both commercial and public space weather enterprises. Further, they agreed that another meeting would be held during 2009 SWW and that as-needed teleconferences would be held in the intervening period.

Space weather: science and effects

AbstractFrom the point-of-view of somebody standing outside on a cold winter night looking up at a clear cloudless sky, the space environment seems to be of a peaceful and stable nature. Instead, the opposite is found to be true. In fact the space environment is very dynamic on all spatial and temporal scales, and in some circumstances may have unexpected and hazardous effects on technology and humans both in space and on Earth. In fact the space environment seems to have a weather all of its own – its own “space weather”. Our Sun is definitely the driver of our local space weather. Space weather is an interdisciplinary subject covering a vast number of technological, scientific, economic and environmental issues. It is an application-oriented discipline which addresses the needs of “space weather product” users. It can be truly said that space weather affects everybody, either directly or indirectly. The aim of this paper is to give an overview of what space weather encompasses, emphasizing how solar-terrestrial physics is applied to space weather. Examples of “space weather product” users will be given highlighting those products that we as a civilization are most dependent on.

A Good Start: Workshop Tackles Space Weather Economics

As I wrote earlier this year, reliable estimates of the economic impacts of a space weather event on technologies have often been seriously lacking (see L. Lanzerotti, Space Weather, 6, S01002, doi:10.1029/2007SW000385, 2008). However, I am happy to note that the Space Studies Board of the U.S. National Research Council took an important step toward setting a framework for achieving some of these “reliable estimates” in a workshop that was held in late May in Washington, D. C. The meeting drew active participation from the academic research community and major government agencies in the National Space Weather Program (http://www.nswp.gov), as well as a significant number of commercial interests large and small. These latter included enterprises that use space weather information for design decisions and/or successful operations, as well as vendors of space weather products and services. The workshop explored several issues related to the economics of space weather. For example, the climatology of space radiation is essential for the design of the long-lived communications satellites that occupy geosynchronous orbit. Current radiation climate models are 30 or more years old and do not reflect major discoveries in the past few decades. Closely tied to this is the absence of reliable information on the statistics of the radiation environment: Are there upper limits to expected flux values, and should designs be based upon such limits (if they are known) or on some lesser (and less expensive to implement) values? What are the design and operations costs for not knowing this information? What are the costs to achieve such information and thus to make future design processes more robust? The policy-oriented participants provided many provocative (and productive) insights on space weather and its economic effects. These included discussions of the prioritization of risks (including space weather) to a business or government activity, as well as the perception of risks to the public. An important realization stressed by several participants was the central role of the complex electricity grid across the nation that underpins essentially all contemporary technologies. What is the risk of a collapse of a major part of the grid under a space weather event? Equally important, can this risk and its economic consequences be examined without causing a “sky is falling” mentality? Where does a space weather risk to the grid rank with respect to other risks, natural and man-made? This workshop was an important initial forum for assembling a diverse and very engaged group of individuals and organizations centrally involved with space weather concerns. The discussions illuminated numerous unresolved engineering, science, and policy issues related to the economics of space weather. However, solid economic information was often lacking in the discussions, partly because of the absence of such data and partly because of proprietary concerns. I hope the National Research Council can use this initial endeavor as the beginning of a more extensive process to delve into space weather economics. Louis J. Lanzerotti is editor of Space Weather and a distinguished research professor of physics at the New Jersey Institute of Technology.

An experimental approach to understanding the optical effects of space weathering

The creation and accumulation of nanophase iron (npFe 0) is a principal mechanism by which spectra of materials exposed to the space environment incur systematic changes referred to as “space weathering.” Since there is no reason to assume that cumulative space weathering products throughout the Solar System will be the same as those found in lunar soils, these products are likely to be very dependent on the specific environmental conditions under which they were produced. We have prepared a suite of analog soils to explore the optical effects of npFe 0. By varying the size and concentration of npFe 0 in the analogs we found significant systematic changes in the Vis/NIR spectral properties of the materials. Smaller npFe 0 (<10 nm in diameter) dramatically reddens spectra in the visible wavelengths while leaving the infrared region largely unaffected. Larger npFe 0 (>40 nm in diameter) lowers the albedo across the Vis/NIR range with little change in the overall shape of the continuum. Intermediate npFe 0 sizes impact the spectra in a distinct pattern that changes with concentration. The products of these controlled experiments have implications for space-weathered material throughout the inner Solar System. Our results indicate that the lunar soil continuum is best modeled by npFe 0 particles with bulk properties in the ∼15–25 nm size range. Larger npFe 0 grains result in spectra that are similar in shape to the Mercury continuum. The continuum of S-type asteroid spectra appear to be best represented by low abundances of npFe 0. The size of asteroidal npFe 0 is similar to that of lunar soils, but slightly smaller on average (∼10–15 nm).

First-principles modeling of geomagnetically induced electromagnetic fields and currents from upstream solar wind to the surface of the Earth

Abstract. Our capability to model the near-space physical phenomena has gradually reached a level enabling module-based first-principles modeling of geomagnetically induced electromagnetic fields and currents from upstream solar wind to the surface of the Earth. As geomagnetically induced currents (GIC) pose a real threat to the normal operation of long conductor systems on the ground, such as high-voltage power transmission systems, it is quite obvious that success in accurate predictive modeling of the phenomenon would open entirely new windows for operational space weather products. Here we introduce a process for obtaining geomagnetically induced electromagnetic fields and currents from the output of global magnetospheric MHD codes. We also present metrics that take into account both the complex nature of the signal and possible forecasting applications of the modeling process. The modeling process and the metrics are presented with the help of an actual example space weather event of 24–29 October 2003. Analysis of the event demonstrates that, despite some significant shortcomings, some central features of the overall ionospheric current fluctuations associated with GIC can be captured by the modeling process. More specifically, the basic spatiotemporal morphology of the modeled and "measured" GIC is quite similar. Furthermore, the presented user-relevant utility metrics demonstrate that MHD-based modeling can outperform simple GIC persistence models.

US‐TEC: A new data assimilation product from the Space Environment Center characterizing the ionospheric total electron content using real‐time GPS data

The potential of data assimilation for operational numerical weather forecasting has been appreciated for many years. For space weather it is a new path that we are just beginning to explore. With the emergence of satellite constellations and the networks of ground‐based observations, sufficient data sources are now available to make the application of data assimilation techniques a viable option. The first space weather product at Space Environment Center (SEC) utilizing data assimilation techniques, US‐TEC, was launched as a test operational product in November 2004. US‐TEC characterizes the ionospheric total electron content (TEC) over the continental United States (CONUS) every 15 min with about a 15‐min latency. US‐TEC is based on a Kalman filter data assimilation scheme driven by a ground‐based network of real‐time GPS stations. The product includes a map of the vertical TEC, an estimate of the uncertainty in the map, and the departure of the TEC from a 10‐day average at that particular universal time. In addition, data files are provided for vertical TEC and the line‐of‐sight electron content to all GPS satellites in view over the CONUS at that time. The information can be used to improve single‐frequency GPS positioning by providing more accurate corrections for the ionospheric signal delay, or it can be used to initialize rapid integer ambiguity resolution schemes for dual‐frequency GPS systems. Validation of US‐TEC indicates an accuracy of the line‐of‐sight electron content of between 2 and 3 TEC units (1 TECU = 1016 el m−2), equivalent to less than 50 cm signal delay at L1 frequencies, which promises value for GPS users. This is the first step along a path that will likely lead to major improvement in space weather forecasting, paralleling the advances achieved in meteorological weather forecasting.

Evidence of space weathering in regolith breccias I: Lunar regolith breccias

Abstract— We have analyzed a suite of lunar regolith breccias in order to assess how well space weathering products can be preserved through the lithification process and therefore whether or not it is appropriate to search for space weathering products in asteroidal regolith breccia meteorites. It was found that space weathering products, vapor/sputter deposited nanophase‐iron‐bearing rims in particular, are easily identified in even heavily shocked/compacted lunar regolith breccias. Such rims, if created on asteroids, should thus be preserved in asteroidal regolith breccia meteorites. Two additional rim types, glass rims and vesicular rims, identified in regolith breccias, are also described. These rims are common in lunar regolith breccias but rare to absent in lunar soils, which suggests that they are created in the breccia‐forming process itself. While not “space weathering products” in the strictest sense, these additional rims give us insight into the regolith breccia formation process. The presence or absence of glass and/or vesicular rims in asteroidal regolith breccias will likewise tell us about environmental conditions on the surface of the asteroid body on which the breccia was created.

Challenges Facing the U.S. Space Weather Public‐Private Sector Partnership

America's reliance on technological systems that are vulnerable to space weather is growing at a rapid pace. Because such vital everyday technology as electric power grids, satellites, and navigation and communication systems are affected by space weather, it is essential to have the best possible space weather services. Although both the federal government and the private sector provide the bulk of currently available space weather products and services, a partnership between the two has been slow to develop and currently faces several challenges.

Integrating Space Weather and Meteorological Products for Aviation

NOVEMBER 2003 AMERICAN METEOROLOGICAL SOCIETY | ne might think that solar flares, coronal mass ejections, and geomagnetic storms are phenomena that only interest space scientists. However, conditions on the sun, in the solar wind, and within the Earth’s magnetic field, otherwise known as “space weather,” can affect a wide variety of ground and space technologies. For example, solar and geomagnetic events can impact satellite operations, navigation, space shuttle and space activities, high-altitude polar flights, electric power distribution, long-line telephone communication, high-frequency (HF) radio communication, and geophysical exploration. As the nation’s reliance on technological systems grows, so does our vulnerability to space weather. The aviation industry is just one of the many user groups that are trying to understand how space weather impacts their operations and what can be done to mitigate disruptions. Airlines are becoming more concerned with flying transpolar routes, losing HF communication, radiation hazards to crews, and the possibility of global positioning system (GPS) errors. Many space weather hazards can be mitigated or avoided if reliable space weather forecasts are available. In response to this need, the federal government has formed the National Space Weather Program, an interagency program under the auspices of the Office of the Federal Coordinator for Meteorology started in 1994, to “achieve an active, synergistic interagency system to provide timely, accurate, and reliable space environment observations, specification, and forecasts.” Currently, space environmental support services are provided by the NOAA Space Environment Center (SEC) and the U.S. Air Force (USAF), which jointly operate the Space Weather Operations (SWO) Forecast and Analysis Center. It is the national and world warning center for disturbances that can affect people and equipment working in space, and provides forecasts, warnings, and alerts of solar and geomagnetic activity to users in government, industry, and the private sector. NOAA/SEC is the official source of space weather alerts and warnings for commercial and public sector customers. INTEGRATING SPACE WEATHER AND METEOROLOGICAL PRODUCTS FOR AVIATION

The response of the high‐latitude ionosphere to the coronal mass ejection event of April 6, 2000: A practical demonstration of space weather nowcasting with the Super Dual Auroral Radar Network HF radars

The ionosphere at high latitudes is the site of important effects in space weather. These include strong electrical currents that may disrupt power systems through induced currents and density irregularities that can degrade HF and satellite communication links. With the impetus provided by the National Space Weather Program, the radars of the Super Dual Auroral Radar Network have been applied to the real‐time specification (“nowcasting”) of conditions in the high‐latitude ionosphere. A map of the plasma convection in the northern high‐latitude ionosphere is continually generated at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) SuperDARN web site using data downloaded in real time from the radars via Internet connections. Other nowcast items include information on the conditions of HF propagation, the spatial extent of auroral effects, and the total cross polar cap potential variation. Time series of various parameters and an animated replay of the last 2 hours of convection patterns are also available for review. By comparing with simultaneous measurements from an upstream satellite, it is possible to infer the effective delay from the detection of changes in the solar wind at the satellite to the arrival of related effects in the high‐latitude ionosphere. We discuss the space weather products available from the JHU/APL SuperDARN web site and their uses by simulating a nowcast of the ionosphere on April 6, 2000, during the arrival of a coronal mass ejection (CME)‐related shock. The nowcast convection pattern in particular satisfies a critical need for timely, comprehensive information on ionospheric electric fields.

The optical properties of the finest fraction of lunar soil: Implications for space weathering

Abstract— The fine fraction of lunar soils (&lt;45 μm) dominates the optical properties of the bulk soil. Definite trends can be seen in optical properties of size separates with decreasing particle size: diminished spectral contrast and a steeper continuum slope. These trends are related to space weathering processes and their affects on different size fractions. The finest fraction (defined here as the &lt;10 μm fraction) appears to be enriched in weathering products relative to the larger size fractions, as would be expected for surface correlated processes. This &lt;10 μm fraction tends to exhibit very little spectral contrast, often with no distinguishable ferrous iron absorption bands. Additionally, the finest fractions of highland soils are observed to have very different spectral properties than the equivalent fraction of mare soils when compared with larger size fractions. The spectra of the finest fraction of feldspathic soils flatten at longer wavelengths, whereas those of the finest fraction of basaltic soils continue to increase in a steep, almost linear fashion. This compositional distinction is due to differences in the total amount of nanophase iron that accumulates in space weathering products. Such ground‐truth information derived from the &lt;10 μm fraction of lunar soils provides valuable insight into optical properties to be expected in other space weathering environments such as the asteroids and Mercury.

Space weathering on airless bodies: Resolving a mystery with lunar samples

Abstract— Using new techniques to examine the products of space weathering of lunar soils, we demonstrate that nanophase reduced iron (npFe0) is produced on the surface of grains by a combination of vapor deposition and irradiation effects. The optical properties of soils (both measured and modeled) are shown to be highly dependent on the cumulative amount of npFe0, which varies with different starting materials and the energetics of different parts of the solar system. The measured properties of intermediate albedo asteroids, the abundant S‐type asteroids in particular, are shown to directly mimic the effects predicted for small amounts of npFe0 on grains of an ordinary chondrite regolith. This measurement and characterization of space weathering products seems to remove a final obstacle hindering a link between the abundant ordinary chondrite meteorites and common asteroids.