CISM Model Aids Investigation of Mercury's Magnetosphere
On January 14, 2008, the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft executed the first of three flybys of Mercury as a step toward its eventual orbit insertion in 2011. During the spacecraft's closest approach to the planet, several interesting magnetospheric phenomena were observed. However, interpretation of these phenomena proved difficult in the absence of concurrent measurements of local solar wind conditions. In order to provide this needed context, CISM's WSA-ENLIL model was used to characterize the solar wind throughout the inner heliosphere. Comparisons of modeled parameters with measurements at several heliospheric locations (Earth, both STEREO spacecraft, and MESSENGER) provided an effective means of validating the model's solar wind specification, thus establishing confidence in its use for interpreting the MESSENGER data. This approach is expected to provide an important tool in future MESSENGER analyses. These results are reported by Baker et al. in the Journal of Geophysical Research [doi:10.1029/2009JA014287, 2009].
First PHD in AAMU Space Science Concentration
In November, 2009, Dr. Fana Mulu-Moore defended her thesis as the first Ph.D. space science graduate in the Physics Department at Alabama A&M University (AAMU). AAMU, a CISM member institution, established a graduate concentration in space science with CISM support that included research collaborations and the hiring of space science faculty members Dr. Amy Winebarger and Dr T.X Zhang. After beginning as a Masters program in 2004-2005, the concentration was recently expanded to a Ph.D. program. Dr. Mulu-Moore's thesis title is, "Determining the Temperature Structure of Solar Coronal Loops Using their Temporal Evolution". She will continue her career as an NRC postdoctoral fellow at NASA Marshall Spaceflight Center, where she will be part of the Hinode X-Ray Telescope team. The photograph shows Dr. Mulu-Moore (third from left) with her thesis committee.
Model Selected for NOAA Operations
As part of its Knowledge Transfer activities, CISM has been working closely with NOAA's Space Weather Prediction Center (SWPC) to assess the potential of the WSA-ENLIL model for solar wind forecasting. This work has included daily forecast runs of the model at SWPC, model assessment and feedback by SWPC forecasters, and iterative development of model capabilities and prototype forecast visualizations. In addition to forecasting characteristics of the continuous "ambient" solar wind, ENLIL incorporates the capability to model many aspects of the solar wind transients that arise from solar coronal mass ejections (CME), events that can trigger severe space weather effects. These CME forecasts use coronagraph observations of a CME as it leaves the sun to initiate a "cone model" representation within the numerical model that then propagates through the ambient solar wind to earth's orbit and beyond, providing a warning time in the range of 1-3 days. Because of the importance of such forecasts to space weather consumers, SWPC has recently selected this model for transition into formal forecast operations; it will be run on supercomputers at NOAA's National Centers for Environmental Prediction (NCEP). CISM is supporting the transition in partnership with SWPC, NCEP, Air Force Research Laboratory, the multi-agency Community Coordinated Modeling Center, and Air Force Weather Agency.
Developing Solar Energetic Particle Predictions with the CISM Model Suite
CISM is using its model suite to develop methods for predicting Solar Energetic Particle (SEP) fluxes, addressing one of the highest priorities for space weather forecasting. SEPs are intense, transient fluxes of extremely energetic particles, mainly protons, that are accelerated by solar flares on the Sun and at shocks caused by coronal mass ejections (CMEs) traveling through interplanetary space. Because of their very high energy, shielding against SEPs on spacecraft is impractical and they can have devastating effects on electronics and humans in space. Work by Luhmann et al. (paper in preparation, JASR, 2009) integrates several elements of CISM research to simulate SEP fluxes for three ICME events. First the "undisturbed" solar wind is determined using CISM's CORHEL model; then, using parameters from an analysis of coronagraph observations of a coronal mass ejection, a simulated ‘cone model’ CME is launched into the modeled solar wind; next, the resulting shock is characterized and the SEP source spectrum is determined for each time it connects to a specific observer location via an interplanetary magnetic field line; finally, the SEPs are propagated through the disturbed solar wind to the observer position at which the flux profile is desired. The figure shows (top) SEP integral fluxes at >10 MeV and >60 MeV observed at L1 during a CME-related SEP event in December 2006 (from the OMNI data base at the NSSDC), and results of using the cone model of the CME to simulate the SEP event at similar energies (bottom) . The modeling approach captures several features of this and other observed events, providing a prospective method of predicting the time profile of CME-associated SEPs.
Improving Forecast Arrival Times for Coronal Mass Ejections
Interplanetary coronal mass ejections (ICME) are the hurricanes of space weather. These large clumps of coronal material are ejected explosively from the sun and, if they impact the earth, can affect processes and equipment ranging from GPS positioning and airline communications to spacecraft electronics and orbits. Because of these diverse effects, predicting the arrival of ICMEs at earth is one of the highest priorities for space weather forecasting. However, while it is often possible to observe ICMEs as they leave the sun and to predict when they are likely traveling toward earth, it has proven very difficult to estimate their arrival times with adequate accuracy. Recent work by graduate student A. Case and coworkers (Geophys. Res. Lett., 35, L15105, 2008) has explained the scatter in arrival times by using the CISM CORHEL model to explore the effects of the ambient solar wind on ICME propagation, and to determine a simple correction formula based on the the background velocity. The figure shows (top panel) the modeled ICME transit times as a function of the ambient solar wind velocity for a variety of initial ICME velocities (colored lines) and (bottom panel) the adjustment time that can be applied to empirical models that do not account for ambient solar wind velocity.
Space Weather Summer School Laboratory Materials Made Available
The CISM Space Weather Summer School
is a 2-week intensive program targeted to first-year graduate students but also attended by undergraduates and space weather professionals. Over 200 participants have attended the Summer School and have given it strong reviews as a unique and effective forum to learn about the multidisciplinary, sun-to-earth, space weather system. The daily schedule includes morning lectures, followed by afternoon laboratory sessions where students further explore the day's topics using CISM model simulations, observational data, and sophisticated visualization tools. CISM has made the laboratory materials publicly available for use by others, for example to supplement lecture courses or for student independent study. Further information is provided in in EOS (Gross et al., Vol 90, p. 13-14, 13 January 2009). Detailed descriptions of the lab activities and the student lab manuals are available under the "CISM Summer School" link at the CISM web site
Simulation of Thermosphere Density Changes During the Solar Cycle
Density variations of the earth's high altitude, neutral atmosphere (thermosphere) reflect important coupling with solar and geomagnetic variability and are responsible for major uncertainties in predicting satellite orbits. These processes are simulated by the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM), a core component of the CISM model suite. To better understand and model the thermosphere variations caused by solar variability, data from the Solar Extreme-ultraviolet Experiment (SEE) on the NASA TIMED satellite were used as input to TIE-GCM for a simulation spanning the declining phase of solar cycle 23 from 2001–2007. Model simulations of the neutral thermospheric density at ~400 km were compared with density measurements obtained from observations of the atmospheric drag on five spherical satellites in low-Earth orbit (top panel). The solar observations greatly improve the model fidelity, and both solar-rotational and solar-cycle variations are accounted for. Additionally, the effects of impulsive geomagnetic storms can be can be seen (e.g., the “Halloween storms” in October-November 2003), and a surprisingly strong seasonal pattern is revealed, especially during solar minimum. These results are described in Liying Qian’s Ph.D. Thesis [Pennsylvania State University, 2007], and in Qian et al., [Adv. Space Res., 2008], and Qian et al., [J. Geophys. Res., submitted].
Solar Eclipse Prediction
On Friday, August 1, 2008, a total solar eclipse will occur within a narrow corridor starting over northern Canada, crossing through northern Russia, western Mongolia, and China. On July 17, in preparation for a prediction of what the solar corona will look like during the eclipse, the SAIC solar physics group started a sophisticated numerical simulation of the corona. A preliminary prediction was completed on July 22, 2008, and a final prediction, using updated magnetic field observations, is expected on July 28, 2008. The figure shows the preliminary predicted polarization brightness in the solar corona, which is produced by white light scattered from electrons, as it would be observed during totality. The simulation for this prediction was performed using the 3D magnetohydrodynamic "MAS" model, which serves as CISM's coronal model. Further details about the model, this prediction, and the final prediction when complete, are available at: http://imhd.net/
Predicting Solar Wind High Speed Enhancements with Coupled Models
High speed enhancements (HSE) of the solar wind's velocity are important drivers of space weather phenomena at earth. Predicting the arrival of HSEs requires modeling both the source of high speed solar wind at the sun, and its propagation through the interplanetary medium to earth. Developing and assessing such coupled modeling capabilities is a key objective of CISM. In an extensive validation of CISM's models, simulations of an eight year period were compared with measurements at earth. As part of this investigation the ability of the models to successfully predict the occurrence and detailed properties HSEs was assessed. The figure shows multiposed epoch plots of magnetic field and velocity components for HSEs that were successfully identified by the models (color), compared with satellite measurements (black). The red curve is the Wang-Shelley-Arge (WSA) kinematic model that serves as CISM's validation baseline. The blue and green curves are results from CISM coupled models, CORHEL and WSA-ENLIL. The value of physics-based, coupled modeling is clearly seen in the improved model comparisons with measurements. This work is published by M.J. Owens et al., in the journal Space Weather, doi:10.1029/2007SW000380, 2008.
Coupled Modeling Of Space Weather Storm Impacts
Among the most important and widespread impacts of space weather are those arising from changes in the earth's ionosphere during "geomagnetic storms", which reflect a chain of complex physical processes beginning at the sun. By altering the density and distribution of charged particles in the ionosphere, storms degrade and disrupt systems ranging from communications to GPS navigation. The Center for Integrated Space Weather Modeling (CISM) is bringing together models of different parts of this system to understand, and ultimately to predict, the effects of such storms. Using the CISM Coupled Magnetosphere Ionosphere Thermosphere model, Jiuhou Lei and coworkers have simulated storm-time changes in the ionosphere's total electron content (TEC) and compared these model values with GPS measurements. The figure shows two time snapshots of modeled (right) and measured (left) changes in the global TEC for a storm that began at approximately 14UT on December 14, 2006 with the arrival at earth of an interplanetary shock. (The color scale units are 1016 electrons/m2. GPS results are unavailable in white areas of the map.) The model successfully captured both the temporal and spatial variations in ionospheric ionization, and also agrees well with the measured magnitudes. This work is reported by Lei et al. in the Journal of Geophysical Research, doi: 10.1029/2007JA012807, 2008.
Numerical Model Used To Determine Radial Particle Diffusion Coefficients
CISM graduate student Chia-Lin Huang has used the Lyon-Fedder-Mobarry (LFM) model to closely examine effects of magnetospheric ULF waves on the dynamics of radiation belt electrons. An important part of her work was to establish the validity of using the simulation-based waves to deduce physically reliable analyses of their effects on particles. To address this issue she compared several properties of the ULF waves generated by the model with those measured by satellites. The figure shows one such comparison, between average ULF power spectral density at geosynchronous orbit as measured by the GOES satellites (top row ) and that calculated from the LFM simulation (bottom row), for three levels of solar wind velocity (left to right). The simulated wave spectra match the measured values remarkably well at dayside local times (between the white lines), where solar wind interactions are expected to be the dominant source of ULF power. After determining that the model adequately represents the relevant properties of the ULF waves, radial diffusion coefficients were calculated by following the trajectories of tens of thousands of test particles in the simulated fields. The resulting coefficients compare well with previous work and demonstrate an exciting technique for using space weather models to separately investigate various contributing factors in a complex physical problem. Dr. Huang completed her PhD at Boston University in December, 2007.
Sun-to-Earth Model Results in Different Heliospheric Conditions
A detailed assessment of CISM's first-generation sun-to-earth model has been performed for two 6- to 7-day periods, representing distinctly different heliospheric conditions. This work, published by Merkin et al. in the journal Space Weather, illustrates both significant capabilities and the non-trivial challenges in predicting the earth's magnetospheric behavior by modeling processes beginning at the solar corona. The figure shows the northern hemisphere potential distribution during one of the two periods, at the peak of an interval when magnetospheric activity is dominantly controlled by the Y component of the interplanetary magnetic field (IMF). On the left, the standalone LFM magnetosphere model is driven by ACE satellite measurements directly upstream of Earth; on the right, the LFM is driven by CISM's corona-heliosphere model (CORHEL), providing a sun-to-earth simulation. While the sun-to-earth model performs quite well in these conditions, it is much less successful in capturing magnetospheric activity that is driven by the quasi-turbulent variations in the Z component of IMF. Systematic model evaluations such as these help clarify the considerations and options for applying space weather models, for example the tradeoff between longer forecast times using a sun-to-earth model and a wider range of model fidelity through incorporating interplanetary measurement data. (reference: Space Weather, doi:10.1029/2007SW000335, 2007)
Coupled Model Analysis of Ionospheric Storm
Ionospheric storms are extreme space weather phenomena involving complex interactions of several processes within the magnetosphere-ionosphere-thermosphere system. CISM scientists have used the Coupled Magnetoshere-Ionosphere-Thermosphere model (CMIT 2.0) to simulate in detail the initial phase of a December 2006 geomagnetic storm, when the geospace system was strongly driven by an interplanetary shock. After validating the fidelity of the simulation, the model was used to investigate the causes of the ionospheric responses and to quantify the relative contributions of different physical processes. The figure shows differences relative to quiet-time values for several quantities at one location (35 deg N, 75 deg W) over 10 hours, beginning approximately 1 hour before shock arrival. Differences in electron density and the rate of change in oxygen ion density are shown in the top and bottom panels. The production-loss and transport terms contributing to the ion density variation are separately shown in the middle four panels. Such "term analyses" are a powerful tool, enabled by sophisticated coupled models such as CMIT, for investigating the behavior of the complex space weather system. For example, in this case it was found that electric field changes are the dominant factor in the initial-phase storm effects in the American sector, although neutral winds and composition changes also contribute. This work is published by Lei et al. in Journal of Geophysical Research, doi:10.1029/2007JA012807, 2008.
AAMU Space Science Students Win Local Research Competition
On March 30, 2007, Alabama A&M University hosted its first Science, Technology, Engineering, and Mathematics (STEM) Day. More than seventy-five local graduate and undergraduate students were invited to present STEM related research posters for competition. Three CISM space science students participated: Idatonye (Julius) Allison, a junior, Samaiyah Farid, a M.S. student, and Fana Mulu, a Ph.D. student. Julius Allison's poster, titled "The Importance of Geometry in Impulsively Heated Loops," placed first in the Natural Science - Undergraduate category. Fana Mulu's poster, titled "A Statistical Study of Solar Cycle Effects on the 27-Day Variation of Geomagnetic Activity," and Samaiyah's Farid's poster, titled "Investigating Solar Plumes Observed During the March 2006 Solar Eclipse," tied for second place in the Natural Science - Graduate category.
Sudden Ionospheric Disturbance Monitors
The Sudden Ionospheric Disturbance Monitor (SID) allows high school and community college students to directly observe space weather phenomena. The SID monitor is an inexpensive ($250) Very Low Frequency (VLF) radio receiver that is tuned to one of several VLF transmitters around the country. Since the signal strength is sensitive to the state of the ionosphere, the monitors provide students with a window into ionospheric variations, such as those caused by solar activity. The SID was developed by the Stanford Solar Group as part of CISM's Grade 6-14 Education program. In this leveraged program, CISM provided support for SID development, while other funds have supported distribution. Approximately 100 monitors have been placed nationally and additional funding has recently been obtained to place monitors world-wide as part of the International Heliophysical Year (IHY). Students share data from this distributed network, providing the opportunity to develop a global view of conditions. Student Leandra Merola, of South Side High School in Rockville Centre, NY, is shown in the picture working on the VLF antenna. Ms. Merola's report on her SID research project placed 3rd out of 120 students in the Regional Round of the Junior Science and Humanities Symposium.
Coupled Modeling Of The Equatorial Ionosphere During Geomagnetic Storms
Physical interactions between the magnetosphere and the ionosphere-thermosphere affect processes in both regions during magnetic storms. CISM's Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model provides an important step for understanding, and ultimately predicting, the coupled system behavior. The new version of CMIT introduces the NCAR TIEGCM model of the ionosphere-thermosphere, providing the capability to study global ionospheric disturbances during geomagnetic storms. The figure shows modeled equatorial vertical ion drifts (red line) compared to measurements by the Jicamarca radar (blue crosses). April 2, 2004, was a quiet day, followed by a significant geomagnetic storm that began at 2 UT on April 3. In the top panel, the stand-alone TIEGCM model captures many of the overall trends, but does not successfully represent the dynamic structure that is caused by interactions with the magnetosphere. The coupled CMIT model, in the bottom panel, provides a much better characterization of the dynamics of the coupled system. Temporal variations in the model are consistent with the data, but somewhat overestimated, due to the lack of a full characterization of region-2 shielding currents. This work, published by Wang et al. in Geophysical Research Letters., doi:10.1029/2008GL035155, 2008, illustrates the importance and promise of using coupled models to represent the complex physics of space weather.
Active Region CME Simulation
Coronal mass ejections (CMEs) are arguably the most spectacular transient solar phenomena. The fastest CMEs, which potentially have the largest space weather impact, typically originate in solar active regions (ARs). Modeling these events is particularly challenging because both the localized AR magnetic field and the overlying fields in the large-scale corona are important. To develop a realistic AR model in the context of the global corona, the thermodynamics of energy transport processes (radiation, coronal heating, thermal conduction) must be included. CISM researchers have developed the first-ever simulation of a specific eruption (the 12 May 1997 event) using a full thermodynamic, global MHD approach. The figure illustrates several stages of evolution of this event, and highlights several features in the simulation that match the observations remarkably well. A more
detailed description and movies of the simulated AR evolution
and simulated coronagraph polarization brightness
are provided here
(Higher quality Quicktime formatted movies are also available for the AR evolution
and coronagraph polarization brightness
Coupled Model Visualization Of Shock Impact
This scientific visualization movie
shows results from CISM's Coupled Magnetosphere Ionosphere Thermosphere (CMIT) model depicting the impact of a shock at the head of a coronal mass ejection on the magnetosphere. The visualization clearly shows the inward motion of the magnetopause and compression of the magnetosphere at the arrival of the shock, which is modeled from solar wind observations, and throughout of the coupled magnetosphere - ionosphere - thermosphere system. Accurate modeling of these types of events is essential for creating reliable space weather predictions.
Coronal Modeling With Realistic Energy Transport
Models of the solar corona typically simplify the energy equation by neglecting important energy transport processes. These "polytropic" models are useful but also have significant limitations. Through scientific and technical advances enabled by CISM, we have significantly improved our coronal modeling capability to include the effects of coronal heating, the conduction of heat parallel to the magnetic field lines, radiative losses, and the acceleration of the solar wind by Alfven waves. We refer to this as the "thermodynamic" MHD model. A principal difficulty in this type of model is related to the extremely steep temperature and density gradients in the transition region, a consequence of the balance between conduction of heat from the hot corona and radiation loss in the transition region. Recent work on the MAS coronal model has provided an important advance that effectively treats the transition region as slightly broadened without compromising the coronal solution. The more accurate representation of energy flow in the thermodynamic MHD model produces a significantly better estimate of the plasma temperature and density in the corona, and allows us to compute simulated EUV and X-ray emission as would be observed from instruments such as SOHO EIT and Yohkoh SXT. The figure shows a comparison of actual (top frames) and simulated (bottom frames) emission for these instruments. (Lionello et al., Astrophysical Journal, 690:902–912, 2009)
Electron Acceleration In Reconnection
A long-standing problem in the study of space and astrophysical plasmas is to explain the production of energetic electrons as magnetic fields 'reconnect' and release energy. In the Earth's magnetosphere, electron energies reach hundreds of thousands of electron volts, whereas the typical electron energies associated with large-scale reconnection-driven flows are just a few electron volts. Observations suggest that these energetic particles are produced in the region where the magnetic field reconnects. In solar flares, upwards of 50 per cent of the energy released can appear as energetic electrons. Recent work by Drake et al. (Nature 443, 553, 2006) has found that electrons gain kinetic energy by reflecting from the ends of the contracting 'magnetic islands' that form as reconnection proceeds. The mechanism is analogous to the increase of energy of a ball reflecting between two converging walls—the ball gains energy with each bounce. The repetitive interaction of electrons with many islands allows large numbers to be efficiently accelerated to high energy. The figure shows (a) simulated particle orbits, and (b) energy and (c) velocity gains of the Fermi accelerated electrons.
Graduate Research Applies Long-Term Global Simulation to Transport Processes
Timothy Guild, the first graduate student to perform and complete his PhD research entirely within CISM's lifetime, used global simulations over a two month interval to study the multi-scale nature of convective transport in the plasma sheet. Dr. Guild's thesis research demonstrates the scientific application of global modeling to augment relatively sparse in situ measurements to understand time varying processes on different scales. A key result of this work is that locally reconnecting field lines in the magnetic lobes initiate flow channels within the simulation that have similar properties to the observed flow enhancements called "bursty bulk flows". Dr. Guild defended his thesis in September, 2006, and has accepted a staff position at the Aerospace Corporation.
2006 CISM Graduate Student Retreat
The fourth annual CISM Graduate Student Retreat was held at the Wachusett Village Inn on September 15-17, 2006. The graduate retreats provide CISM graduate students with the opportunity to build community, organize graduate activities within CISM, plan AccessGrid meetings, and develop professional relationships at the beginning of their careers. Each year part of the retreat focuses on a special topic related to graduate professional development. This year's topic was Professional Writing and Publishing, supported by guest attendee Dr. Brian Anderson, a former space science editor of Geophysical Research Letters. Topics in prior years have been: Ethics, Careers in Space Physics, and Research Funding. Fifteen CISM PhD students from five institutions attended the 2006 retreat together with CISM Director Jeffrey Hughes and Dr. Anderson.
Event-Based Assessments Of Model Performance
The evaluation, improvement, and validation of space weather models relies upon the quantitative comparison of measurements with a model's simulation of the system. While this comparison is straightforward in principle, the detailed definition of a "good" match between model and reality can be challenging and subtle. In a recent publication Owens et al. (J. Geophys. Res., A12105, 2005) demonstrated that several specialized techniques are needed to properly assess key aspects of the modeled solar wind velocity. While conventional mean square error comparisons provide an overall characterization of a model's performance, more sophisticated event-based analyses are required to characterize predictions of rarer events, such as high speed stream transitions, that are of high operational and scientific importance. This work illustrates the large variety of methods that are being applied in CISM's validation and metrics effort.
First Graduates From New AAMU Space Physics Program
Alabama A&M University (AAMU) is a CISM member institution that has recently added a new M.S. concentration in space science. Ms. Fana Mulu (left) and Ms. Samaiyah Farid (right) will be the first physics graduate students to complete the new space physics concentration. They both received their Bachelor's degrees from AAMU in 2004 and entered the graduate program. Ms. Mulu expects to complete her Master's degree in July 2006. Her research concerns developing a method to predict geomagnetic activity using correlations between solar wind parameters and geomagnetic indices. After graduation from AAMU, she plans to enter a Ph.D. program in Atmospheric Science at another university. Ms. Farid expects to complete her Master's degree in December 2006. Her thesis research will be to analyze and model the solar plumes that she observed in Ghana during the March 29, 2006 solar eclipse. Her future plans are to continue studying solar physics in pursuit of a Ph.D. Ms. Mulu and Ms. Farid presented space physics talks at the 2006 National Society of Black Physicists Meeting in San Jose, California. Both young scientists attended the CISM summer school.
CISM Simulation in Major Planetarium Show
CISM researchers provided simulation results for visualizing the earth's magnetic field in a new space show at the Hayden Planetarium of the American Museum of Natural History in New York. The show, "Cosmic Collisions", which opened on March 16th, 2006, uses spacecraft measurements and research simulations to depict a variety of collisions in space. A CISM simulation is used in a segment showing that the earth is bombarded by high energy particles from the solar wind, and how the earth's magnetic field provides protection from those particles.
UPDATE March 2007: Over 1 million visitors have seen "Cosmic Collisions" in its first year at the Hayden Planetarium. It is showing at 9 other planetariums: Denver Museum of Nature and Science; Shanghai Science and Technology Center; Eugenides Planetarium - Athens, Greece; Papalote Museo del Nino - Mexico City; Exploration Place - Wichita, KS; Smithsonian National Air and Space Museum - Washington, DC; Cunard - Queen Mary 2; EcoTarium - Worchester, MA (opening December 2007); Yokahama Science Center - Yokohama, Japan. The magnetosphere visualization is now in the collection of astronomical visualizations of the Hayden Planetarium and is being used as part of their "Digital Universe" and "Field Trip to the Moon" programs for school groups.
CISM SHORT COURSE
As part of its Knowledge Transfer activities CISM has created a two-day short course for delivery at a partner's facility. The course provides a review of space weather, interactive discussions where CISM scientists learn about the partner's space weather activities and concerns, an overview of CISM activities, and training in the use and interpretation of state-of-the-art CISM models and visualization tools. The first two short courses were delivered in August and November 2005 at the Air Force Space Command in Colorado Springs and the Air Force Weather Agency in Omaha. Feedback from both organizations has been very positive and the courses will be repeated every 1-2 years.
Analysis and Visualization with CISM-DX
CISM has developed and released under open source licensing a visualization and analysis package called CISM-DX. CISM-DX addresses the challenge of examining the results from numerical and empirical models together with observational data in an integrated fashion. The tool is capable of providing sophisticated visualizations of results from a diverse set of models and measurements throughout the Sun-Earth system. Details are provided in a recent publication (Wiltberger et al., J. Geophys. Res., doi:10.1029/2004JA010956, 2005). CISM-DX downloads and additional information are available via the link on the CISM web site.
Solar Eruption Model Leads to Rapid Acceleration
A MAS zero-beta coronal simulation has been used to model the eruption of an idealized active region, based on the May 12, 1997 CME event. Sheared magnetic field lines in the active region are subjected to flux cancellation, leading to the eruption with speeds > 900km/s. The leftmost frame shows magnetic field lines in the flux rope at the beginning of the eruption. The center frame shows the field lines about 15 minutes later. The rightmost frame shows the plasma radial velocity at the same time as the middle panel. Yellow (red) colors indicate high (low) speed.
IBM SuperComputer Award
CISM has been awarded a 24 processor supercomputer by the IBM Shared University Research (SUR) program. The system consists of three 8- processor IBM P655 nodes, capable of peak performance of 90 gigaFlops. CISM will use this dedicated supercomputer for model coupling experimentation and coupled model simulations. The Boston University Scientific Computing and Visualization Group will operate and maintain the system.
Space Weather Weekend: A New Diversity Initiative
On April 23-24, CISM held its first annual Space Weather Weekend for students from Minority-Serving institutions. The event was held at Alabama A&M University (AAMU) in Huntsville. Eleven students from eight institutions attended (AAMU, Norfolk State, Grambling U., Howard U., North Carolina A&T, U. of Houston, Downtown, U. of TX at Brownsville). Over the course of the weekend students learned about the Sun, magnetosphere, and ionosphere, and how space weather affects human activity. The students also gained some hands-on experience with models being used for research by CISM, and they also had a chance to talk with CISM faculty about applying to graduate school is space physics and other fields as well. The evaluations filled out by the participants indicates that the weekend opened their eyes to an exciting field of science that they had not known about, and several expressed an interest in applying to CISM graduate schools in the Fall of 2005.
2004-2005 Monthly Science Seminars
CISM holds monthly seminars on central research topics of space weather modeling via the Access Grid, providing participation and discussion at multiple distributed locations. The seminar presentations
are available on our web site. Seminars given in the 2004-2005 academic year were:
- Fluid Dynamics of Sun-to-Earth CME Expansion and Propagation - George Siscoe
- The Coupling Between the Solar Interior and the Solar Corona - George Fisher
- Challenges in Identifying the Mechanism of CME Initiation - Jon Linker Modeling CMEs in the Heliosphere - Pete Riley
- Heliospheric Transients and the Imprint of Their Solar Sources - Nancy Crooker
- SEP Event Modeling for CISM - Janet Luhmann
- Numerical Simulation of Interplanetary Disturbances Using CME Cone Models - Dusan Odstrcil
Coupled-Model Simulation from Sun to Earth
CISM has simulated a space weather event from the Sun to the Earth, and published the results. The simulation coupled models of the solar corona (upper left), solar wind (upper right), Earths magnetosphere (lower left), and the atmosphere/ionosphere (lower right) to track the event from its initiation on the Sun, through the solar wind, to its interactions with, and affects on, the Earth. This simulation represents an important milestone in CISMs development and coupling of models with the goal simulating and understanding space weather from Sun-to-Earth. A series of 22 papers in Journal of Atmospheric and Solar-Terrestrial Physics, Oct-Nov 2004, describe the results of the simulation (Luhmann et al.), development of the CISM models, model coupling, validation, and scientific advances that are involved in CISMs progress toward its goals.
(Click on the right-hand image to see a larger version.)
Outstanding Student Paper Awards
Four CISM graduate students won Oustanding Student Paper awards for their research presentations at the 2004 Fall meeting of the American Geophysical Union. The awardees are Timothy Guild, Chai-Lin Huang, Sarah McGregor, and Kara Perry. Each of the awarded papers presented student-led research involving collaborations of multiple CISM institutions.
- Guild, T, Spence, H, Goodrich, C, Lyon, J, Kepko, L, A Statistical Comparison of the Geotail and MHD Plasma Sheet
- Huang, C, Spence, H, Friedel, R, Lyon, J, Goodrich, C, Model and Data Comparison of Inner Magnetosphere Plasma
- McGregor, SL, Hughes, WJ, Arge, CN, Riley, P, Linker, J, A Comparison of Coronal Magnetic Field and Heliospheric Current Sheet Derived From the MAS and WSA Models
- Perry, KL, Hudson, MK, Elkington, S, Diffusion of Radiation Belt Electrons in Three Dimensions
Sun-to-Earth Modeling Publications in JASTP Special Issue
Twenty two papers on scientific and technical topics across the breadth of CISMs physics-based modeling project were published in the Oct-Nov, 2004 issue of the Journal of Atmospheric and Solar-Terrestrical Physics. These publications represent the vanguard of a growing consensus by the scientific community that an integrated Sun-to-Earth approach is required to adequately understand and ultimately predict many aspects of space weather. The CISM STC provides the first opportunity to address comprehensively the extremely complex Sun-Earth space weather system.
Knowledge Transfer to NOAA/SEC
Knowledge of the prevailing ambient solar wind topology is essential for understanding and accurately modeling coronal mass ejections and the dynamics of their propagation to Earth on a time scale of 3-4 days. In collaboration with N. Arge and D. Odstrcil the CISM Knowledge Transfer Group is implementing a coupled empirical/physical model that will compute this topology and propagation on an 8-hour time scale. A prototype of such a model has already been demonstrated and validated at the Space Environment Center at NOAA and a continuously-running version will be in place in Fall, 2005.
In the top panel synoptic maps from the Mount Wilson Solar Observatory (WSO) are shown which are the input to the Wang-Sheeley-Arge (WSA) potential field source surface model shown in the middle panel. These time-dependent inner boundary conditions are then used to drive the heliospheric MHD model Enlil which generates the 3-D velocity surface shown in the lower right panel. The end result for of interest to the forecaster is the solid line showing the speed of the solar wind at Earth (L1) which is compared to in situ spacecraft observations, which are plotted as symbols.
CISM in National Geographic
A CISM model, visualizations, and expertise were featured in the July, 2004 National Geographic magazine in a cover story entitled "A Stormy Star". Visualizations of an LFM simulation were used to illustrate the effects of a coronal mass ejection impacting the earth's magnetosphere (pages 28-29). Several CISM scientists provided scientific expertise for the article.