Boulder Solar Day Program

International Coordination of Space Weather Author: Terry Onsager   Affiliation: NOAA/SWPC
Title: International Coordination of Space Weather
Abstract: The growing global interest in space weather has led to numerous international activities that are serving to foster cooperation and increase opportunities. This coordination is important for our data infrastructure, research developments, and the provision of operational services. Among the organizations that are contributing to this global coordination are: the International Space Environment Service, the World Meteorological Organization, the United Nations Office for Outer Space   Affairs, the International Civil Aviation Organization, the Coordination Group for Meteorological Satellites, and the International Committee on GNSS. The NOAA Space Weather Prediction Center is working closely with these and other organizations to broaden the engagement in space weather around the world. This presentation will introduce the roles of these various organizations in promoting space weather and discuss opportunities we have for advocacy through them.

Extending the Extended Solar Cycle into the Outer CoronaAuthor: S.J. Tappin   Affiliation: NSO/Sac Peak
Title: Extending the Extended Solar Cycle into the Outer Corona
Abstract: I shall present observations of the "extended sola cycle" activity in white-light coronagraphs, and compare them with the more familiar features seen in the Fe~XIV green-line corona. I will show that the coronal activity zones seen in the emission corona can be tracked high into the corona. The peak latitude of the activity, which occurs near solar maximum, is found to be very similar at all heights. But the equatorward drift of the activity zones is faster at greater heights, and that during the declining phase of the solar cycle, the lower branch of activity (that associated with the current cycle) disappears at about 3 solar radii. This implies that that during the declining phase of the cycle, the solar wind detected near Earth is likely to be dominated by the next cycle. The so-called "rush to the poles" is also seen in the higher corona, and is found to start at lower latitudes at greater heights. Comparison of the rush to the poles in cycles 23 and 24 suggests that it is highly likely that the maximum of solar cycle 24 will be significantly later in the southern hemisphere than in the north.

Helioseismology of Pre-Emerging Active RegionsAuthors: Graham Barnes(1), Aaron Birch(1,2), K.D. Leka(1), Doug Braun(1), Tera Dunn(1), Brenda Javornik(1), Irene Gonzalez-Hernandez(3)
Affiliations: (1) NWRA, (2) MPS, (3) NSO
Title: Helioseismology of Pre-Emerging Active Regions
Abstract: Local helioseismology potentially provides a way of detecting magnetic fields before they emerge through the photosphere. I will summarize a study which uses helioseismic holography to search for pre-emergence signatures of solar active regions in data from the GONG network. The subsurface properties of a sample of about 100 active regions, and a similar control sample of quiet su regions, have been compared using various statistical techniques. A similar analysis for the surface magnetic field measured by SOHO/MDI will also be presented. There are some significant and surprising differences between ou samples. The results of this investigation may shed some light on the mechanism responsible for flux emergence, and certainly illustrate the care which must be taken in conducting such an investigation.

Solar Probe Plus: Mission Profile and Science GoalsAuthors: David M. Malaspina(1), Robert E. Ergun(1,2)
Affiliations: (1)University of Colorado, LASP; (2)University of Colorado, Dept. of Astrophysics & Planetary Sciences
Title: Solar Probe Plus: Mission Profile and Science Goals
Abstract: The Solar Probe Plus mission (now in Phase B!) is a historic endeavor to send a spacecraft closer to the Sun than ever before, with the goal of using in-situ and near-Sun remote measurements to address some of the longest-standing questions in heliophysics:
What processes maintain the 1,000,000 K corona above the 6,000 K photosphere? What processes are responsible for heating and accelerating the solar wind? What are the source populations, acceleration mechanisms, and transport mechanisms for solar energetic particles (SEPs)? What is the distribution of interplanetary dust close to the Sun?
The mission profile will be presented, including the planned orbit, instrumentation, measurement challenges, and data collection strategy. The mission-motivating questions and specific measurements that Solar Probe Plus will make to help answer them will also be discussed. Emphasis will be on the electric and magnetic observations to be made by the FIELDS instrument suite as well as the CU/LASP contributions to FIELDS.

DSCOVR: NOAA is finally going to L1Authors: Doug Biesecker(1), Alysha Reinard(1,2)
Affiliations: (1)NOAA/NWS/SWPC; (2)CU/Cires
Title: DSCOVR: NOAA is finally going to L1
Abstract: Scheduled to launch in 2014, the DSCOVR mission already has a long, sordid story to tell. In 1998, Vice President Gore proposed an observatory that would be stationed at L1 that would continuously take pictures of the daylit side of the Earth that would be beame into classrooms around the globe. Doomed almost from the start, the National Academy of Sciences stepped in and declared it "strong and scientifically vital." The revived mission was named Triana, after the first member of Columbus' crew to sight land in the Americas. Placed in storage in 2001 and renamed the Deep Space Climate Observatory (DSCOVR), this spacecraft sat idle until 2008, when NOAA and the USAF funded NASA to power it on and check out the status of the subsystems. This checkout showed the spacecraft to be in excellent health and helped to verify refurbishment costs. With this NOAA, NASA, and the DoD came to agree to a partnership to fly DSCOVR. Beginning with FY11, NOAA has provided funding to NASA to refurbish DSCOVR and the space weather sensors. In the FY12 budget, the DoD secured the funds to provide the DSCOVR launch. This talk will briefly review the history of DSCOVR, discuss the plans for refurbishment, show the space weather capabilities of the spacecraft, and finally cover the NOAA/SWPC plans for new products from this mission.

Forward synthesized Spectroscopy of a Sunspot PenumbraAuthors: Alexandra Tritschler(1), Han Uitenbroek(1), Matthias Rempel(2)
Affiliations: (1)NSO, Sunspot; (2)HAO/NCAR
Title: Forward synthesized Spectroscopy of a Sunspot Penumbra
Abstract: We present preliminary results from a forward modeling of the Zeeman-insensitive Fe I 557.6 nm spectral line using a snapshot of a three-dimensional radiative simulation of solar magneto-convection of a sunspot and its immediate surroundings as an input model.

On the height of the 24 February 2011 white-light flare Authors: JuanCarlos Martínez-Oliveros(1), Hugh S. Hudson(1,2), Gordon J. Hurford(1,3), Säm Krucker(1,3 ), R. P. Lin(1), Charles Lindsey(4), Sebastien Couvidat(5), Jesper Schou(5), and W. T. Thompson(6)
Affiliations: (1)Space Sciences Laboratory, UC Berkeley; (2)School of Physics and Astronomy, University of Glasgow; (3)Institute of 4D Technologies, School of Engineering, University of Applied Sciences, Switzerland; (4)NWRA, CORA Division; (5)W. W. Hansen Experimental Physics Laboratory, Stanford University; (6)Adnet Systems, Inc., NASA Goddard Space Flight Center
Title: On the height of the 24 February 2011 white-light flare
Abstract: We describe observations of a white-light flare (SOL2011-02-24T07:35:00, M3.5) close to the limb of the Sun, from which we obtain estimates of the heights of the optical continuum sources and those of the associated hard X-ray sources. For this purpose we use hard X-ray images from the Reuven Ramaty High Energy Spectroscopic Explorer (RHESSI), and optical images at 6273 Å from the Solar Dynamics Observatory (SDO). We find that the centroids of the impulsive-phase emissions in white light and hard X-rays (30−80 keV) match closely in central distance (angular displacement from Sun center), within uncertainties of order 0.2. This directly implies a common source height for these radiations, strengthening the connection between visible flare are continuum formation and the accelerated electrons. We also estimate the absolute heights of these emissions, as vertical distances from Sun center.

Impact of Solar Spectral Variability on Middle Atmospheric Constituents Author: Aimee Merkel   Affiliations: CU/LASP
Title: Impact of solar spectral variability on middle atmospheric constituents
Abstract: The Spectral Irradianc Monitor (SIM) measures solar spectral variability in the 200–2400 nm range, accounting for about 97% of the total solar irradiance (TSI) This instrument monitored the descending phase of solar cycle 23 and is now continuing observations in the rising phase of cycle 24. The SORCE observations show 3–5 times more variability in ultraviolet (UV) radiation than predicted by a proxy model. To estimate the atmospheric response to the solar variability implied by these observations, quiet sun and active solar reference spectra were created as input into the Whole Atmosphere Community Climate Model (WACCM). The SIM observations were combined with the ultraviolet SORCE SOLSTICE measurements and Solar Radiation Physical Modeling (SRPM) estimates in the infrared to generate the reference spectra. The model output suggests a very different response in photochemically active species in the stratosphere and mesosphere than from atmospheric forcing from semi-empirical models of SSI. For instance the higher UV variability from SORCE induced a 4% reduction in ozone concentration above 40 km at solar active conditions. This atmospheric structure is commensurate with contemporaneous observations of ozone from AURA-MLS and SABER.

The automated detection and analysis of short-term changes in coronal dimmings Authors: Larisza Krista(1), Alysha Reinard(2)
Affiliations: (1)NOAA/SWPC; (2)CU/CIRES
Title: The automated detection and analysis of short-term changes in coronal dimmings
Abstract: We present a new approach to the detection of coronal dimming regions. The Coronal Hole Evolution (CHEVOL; Krista 2011) algorithm was adapted to study the temporal evolution of dimming region properties using either SDO/AIA and HMI or SOHO/EIT and MDI data. The algorithm was found successful in locating dimming regions with relatively low intensities and clear boundaries. The area, location and magnetic properties of dimming regions were determined at high temporal cadence from the time of their appearance to the time of their disappearance. As a result, we were able to study the properties and spatial evolution of the dimming regions. Four dimming regions were analysed, including a recurring dimming near the same active region. The recurring dimming formed in a very similar way, first expanding then shrinking and stabilizing as a coronal hole. The repeated similar behaviour may indicate a quasi-steady magnetic configuration. With an extended dimming list, the method will be used to study the magnetic field reconfiguration caused by reconnection and to relate dimming region properties to those of CME's.

Spectroscopic observations of coronal mass ejections, coronal dimming and EUV jets Authors: Hui Tian(1), Scott W. McIntosh(1)   Affiliations: (1)HAO/NCAR
Title: Spectroscopic observations of coronal mass ejections, coronal dimming and EUV jets
Abstract: Solar eruptions, particularly coronal mass ejections (CMEs) and extreme-ultraviolet (EUV) jets, have rarely been investigated with spectroscopic observations. We analyze several data sets obtained by the EUV Imaging Spectrometer onboard Hinode and find various types of flows during CMEs and jet eruptions. We found weak high-speed (~100 km/s) outflows in CME induced dimming regions, temperature-dependent outflows (speed increases with temperature) immediately outside the dimming region, and strong high-speed (~200 km/s) outflows associated with the CME ejecta and EUV jets. We have made plasma diagnostics (density, temperature, mass) for the dimming regions and CME/jet ejecta. Our results suggest that spectroscopic observations can provide useful information on the kinematics and plasma properties of solar mass eruptions.

Imaging solar wind structuresAuthors: Craig DeForest(1); Tim Howard(1), Dave McComas(1), James Tappin(2), and Alysha Reinard(3)
Affiliations: (1)SwRI; (2)NSO; (3)CU/CIRES
Title: Imaging solar wind structures
Abstract: We will give an overview of some recent results from the heliospheric imaging instruments on board STEREO, using our recent post-processing pipeline. The new results reveal kinematics, mass, and entrained magnetic field of disconnection events from the Sun; yield positive confirmation of the connection between interplanetary CME-associated voids and solar coronal flux ropes; and hint at the source of turbulence and variability in the solar wind. We will conclude with a discussion of the future of heliospheric imaging.

The role of network magnetic field in supergranular scale selection Authors: Jesse Lord(1), Mark Rast(1), Matthias Rempel(2)
Affiliations: (1)LASP, CU; (2)HAO
Title: The role of network magnetic field in supergranular scale selection
Abstract: We examine the role of the magnetic field in solar surface convection using the MURaM radiative MHD code. Comparing two 74x74x16 Mm simulations of the solar atmosphere, one without magnetic field and one with an initially uniform and vertical 10 Gauss field, we investigate the role of magnetic field in supergranular scale selection. We find that the simulation with magnetic field has two peaks in the photospheric kinetic energy spectrum, one corresponding to granular size scales and a second peak near 24 Mm, while the purely hydrodynamic simulation has a single peak near the size scale of granulation. We examine two possible physical mechanisms which may underlie this increased power at low wavenumbers: the decreased opacity in magnetic elements near the photosphere which increases the radiative cooling there and the coupling, by regions of high magnetic flux density in convective downflows, of deeper larger scale motions to the photosphere. In particular, we run a series of simulations with artificially adjusted radiative cooling based on magnetic field strength and examine the change in size scales at the photosphere.

Magneto Acoustic Energetics Study of the Seismically Active Flare of 15 February 2011Authors: J.D. Alvarado-Gómez(1), J.C. Buitrago-Casas(1), J.C. Martinez-Oliveros(2), C. Lindsey(3), H. Hudson(2,4), B. Calvo-Mozo(1)
Affiliations: (1)Observatorio Astronómico Nacional, Universidad Nacional de Colombia, Bogotá, Colombia; (2)Space Sciences Laboratory, University of California, Berkeley, CA, USA; (3)NWRA, CORA Division, Boulder, CO, USA; (4)Department of Physics & Astronomy, University of Glasgow, Glasgow, Scotland, UK
Title: Magneto Acoustic Energetics Study of the Seismically Active Flare of 15 February 2011
Abstract: Multi-wavelength studies of energetic solar flares with seismic emissions have revealed interesting common features between them. We studied the first GOES X class flare of the 24th solar cycle detected by the Solar Dynamics Observatory (SDO). For context, seismic activity from the flare SOL2011-02-15T01:55-X2.2, in NOAA AR 11158 is reported in the literature (Kosovichev, 2011; Zharkov et al., 2011). Based on Dopplergram data from the Helioseismic and Magnetic Imager (HMI), we applied standard methods of local helioseismology in order to identify the seismic sources in this event. RHESSI hard X-ray data is used to check the correlation between the location of the seismic sources and the particle precipitation sites in during the flare. Using HMI magnetogram data, the temporal profile of fluctuations in the photospheric line-of-sight magnetic field is used to estimate the magnetic field change in the region where the seismic signal was observed. This leads to an estimate of the work done by the Lorentz-force transient the photosphere of the source region. In this instance this is found to be a significant fraction of the acoustic energy in the attendant seismic emission, suggesting that Lorentz force can contribute significantly to the generation of sunquakes. However, there are regions in whic the signature of the Lorentz-force is much stronger from which no significant acoustic emission emanates.

Testing the truthiness of sunspot simulations Authors: Han Uitenbroek(1), Alexandra Tritschler(1)
Affiliations: (1)NSO/Sacramento Peak
Title: Testing the truthiness of sunspot simulations
Abstract: We use spectro-polarimetric forward modeling of the FeI 557.6, 630.2 and 1564.8 nm lines to explore the realism of recent Rad-MHD simulations of Sunspot structure, with particular emphasis on the the diagnostic value of these lines. Examples are the detectability of convective flows in the penumbra, the accuracy of Doppler measurements in the presence of molecular lines, and the requirements for high resolution of future telescopes.

Temperature dependence of EUV line parameters in network and internetwork regions for quiet Sun and coronal hole Authors: Xin Wang(1), Scott W. McIntosh(2), Hui Tian(2)
Affiliations: (1)HAO/Peking University; (2)HAO/NCAR
Title: Temperature dependence of EUV line parameters in network and internetwork regions for quiet Sun and coronal hole
Abstract: By using SUMER observations, we study the temperature dependence of the intensity contrast, Doppler shift, non-thermal width and profile asymmetry in network and internetwork regions for both the quiet Sun (QS) and coronal holes (CHs). In network regions, most of the transition region (TR) line profiles are more red shifted (by 0-5km/s) and narrower (by 1-6km/s) in QS than in CH. In the network, the RB asymmetries of all the selected TR and coronal line profiles are smaller (more blueward) in CH than in QS. While in the interwork region the difference disappears. In addition, we also systematically investigate differential emission measures (DEM) and electron densities and found different behavior in network and internetwork regions by using joint observations of SUMER and EIS. Our results suggest that the mass cycle between the chromosphere and corona mainly occurs in the network and one needs to separate network and internetwork when discussing thermal and dynamic properties of the solar atmosphere.

Automatic Detection of Emerging Magnetic Flux with SDO/HMI Authors: Derek Lamb(1), Craig DeForest(1)   Affiliation: SwRI
Title: Automatic Detection of Emerging Magnetic Flux with SDO/HMI
Abstract: Flux emergence is central to a host of problems in solar dynamics, from the birth of new active regions and the space weather effects that result, to the maintenance of quiet sun magnetism at all phases of the solar cycle. The SWAMIS-EF emerging magnetic flux region detection module is running on near-real-time magnetograms from the Solar Dynamics Observatory. This enables near-real-time automated detection and cataloging of emerging flux regions from the active region scale down to the scale of the supergranular magnetic network. We will present an overview of the emerging flux detection algorithm, show some detailed observations of emerging flux at a variety of spatial scales, and compare the flux emergence detected by the algorithm over a month-long time period with previously-published estimates of the magnetic flux emergence rate. Such an automated algorithm enables such previously-difficult measurements to now be routinely made.

The Solar Oxygen Crisis: a cautionary tale of forensic spectroscopy Author: Thomas Ayres   Affiliation: CU/CASA
Title: The Solar Oxygen Crisis: a Cautionary Tale of Forensic Spectroscopy
Abstract: Recent work on the solar oxygen problem takes a comprehensive view by examining not only atomic oxygen absorptions in the visible spectrum of the Sun, but also oxygen-bearing molecules (specifically CO) in the thermal infrared. The 3D convection snapshots utilized in the study are subjected to a range of tests to qualify them for abundance work, including matching visible continuum disk center absolute intensities, limb darkening behavior, as well as the extensive damping wings of Ca II H and K, and their center-limb effect. The current generation of 3D models do an excellent job of reproducing the Doppler lineshapes of a wide range of atomic, ionic, and molecular transitions, but also the therma stratification in the middle photosphere is systematically misunderestimated by a few hundred degrees. The temperature deficit likely occurs because these models currently lack nonradiative heating, aside from the bulk hydrodynamics, which becomes increasingly important with increasing altitude. The temperature deficit has little influence on the key O I forbidden lines near 630 nm, but a rather profound effect on the CO rovibrational bands at 2300 and 4600 nm (which form in the middle photosphere owing to the favorable thermal/pressure environment there). The derived oxygen abundance is very sensitive to how one treats the 3D snapshots, specifically how one reconciles inconsistencies in the 3D temperature-pressure profiles with respect to detailed equation of state and opacity calculations utilized in the independent, post-facto spectrum synthesis.

The future solar-terrestrial physics program at HAO Authors: Michael Thompson   Affiliation: HAO/NCAR
Title: The future solar-terrestrial physics program at HAO
Abstract: HAO has a long and distinguished history of contributions to advancing solar physics. The present-day scientific program of HAO encompasses solar physics, physics of the heliosphere, the study of geospace and space weather, and the physics of the Earth's magnetosphere and upper atmosphere. Moreover, as part of NCAR, the Federally Funded Research and Development Center (FFRDC) of the of the NSF's Division of Atmosphere and Geospace Sciences, HAO has a commitment to serve the wide community of solar-terrestrial physics. This commitment is embodied in HAO's mission statement, which is "to understand the behavior of the Sun and its impact on the Earth, to support, enhance, and extend the capabilities of the university community and the broader scientific community, nationally and internationally, and to foster the transfer of knowledge and technology". In this talk I shall seek to highlight the exciting ways in which HAO is fulfilling this mission, with new community facilities and scientific developments, and yes, I probably shall say something about the evolving solar physics infrastructure in Boulder and the needs of ground-based solar physics in the US as a whole.