In addition to examining how mass varies in prominences and the importance of mass loss in CME initiation, I will address the controversial question of whether flux ropes exist prior to a CME by looking at prominence events in which swirling or rotating occurs. This type of swirling motion is detected in many filaments that are non-erupting as well as those that erupt. The analysis of several such events will be presented in an attempt to understand more about the causes of this type of motion and its relationship to CMEs.
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In my presentation, I will review evidence pointing to the low solar O abundance, and then describe some recent work by myself and collaborators, as well as by the 3-D convection team led by Martin Asplund, concerning the oxygen bearing molecule carbon monoxide. We both confirm that the solar 2.5-5 micron rovibrational bands of CO can be well matched with a low oxygen abundance, for a photospheric temperature profile consistent with that of the 3-D convective model. At the same time, however, my colleagues and I showed that at least the mean thermal profile of the 3-D model conflicts with visible continuum center-limb behavior, and that of the CO bands as well. We concluded that the mean temperatures of the Asplund model are too cool in the CO forming layers, thus resulting in a low O abundance from that (highly temperature sensitive) diagnostic. I also present new comparisons based on the temperature responsive Ca II H and K wings which again show that the Asplund mean model is too cool in the middle photosphere. I will discuss some (obvious) theoretical reasons why this might be the case, and also outline future observational tests to better constrain empirical convection properties in the mid photospheric layers where the key CNO diagnostic molecular species (CO, CN, CH, OH) arise. << Hide Extended Entry

Modeling waves in such a geometry is problematical since it is useful to define a magnetically based coordinate system for this problem, but this geometry does not correspond to the radially stratified ionosphere. To resolve this problem, a non-orthogonal coordinate system can be used in this modeling that can accommodate both the structure of the magnetic field and the plasma. The model is useful in treating a variety of ULF wave problems in the magnetosphere, such as Pc1 propagation through the ionospheric waveguide, the propagation of Pi2 waves through the plasmasphere and ionosphere, and the study of plasmaspheric cavity modes and field line resonances that are important for wave-particle interactions in the ring current. << Hide Extended Entry

I show that the dynamo saturates through this feedback at a field strength of around 10-20 kG and that the equatorward transport of field by the meridional flow at base of the convection zone (essential for flux-transport dynamos) is not significantly reduced. The non-linear dynamo is capable of explaining the high latitude branch of torsional oscillations (with correct amplitude and phase relation to the magnetic butterfly diagram), but cannot explain the low latitude branch through macroscopic Lorentz-force feedback. I present a compound model that includes a parameterization of enhanced radiative losses in the active region belt (due to smale scale magnetic flux), and show that this can provide the correct oscillation pattern in low latitudes close to the surface as a consequence of a thermal wind balance. << Hide Extended Entry

The function is a Finite Impulse Response (FIR) function and is derived empirically from all available data. Once the FIR is available, it can be used to extrapolate the desired irradiances backward in time to 1874, the beginning of the reliable sunspot area record from Greenwich. We have tested the technique and found it robust. I will describe our reconstructions of the total solar irradiance and several spectral irradiances, including ultraviolet and 10.7cm radio flux.

If time permits, I will briefly discuss other ongoing research projects at the San Fernando Observatory. << Hide Extended Entry

Our team has obtained high precision long-baseline interferometric observations of Vega in the K-band (2 microns) with the Center for High Angular Resolution Astronomy (CHARA) Array located on Mount Wilson, California. These data probe Vega's photosphere with baselines from 100 meters to 260 meters, sampling the star's projected brightness profile. I have constructed 2-D synthetic intensity maps from a large grid of model atmospheres to fit these data. I will discuss our tests of Von Zeipel's predictions and the constraints on Vega's fundamental parameters and orientation. << Hide Extended Entry

I will review some recent work on eclipsing binaries and show how these stars, besides being interesting objects in and of themselves, continue to make valuable contributions to many areas of astrophysics. << Hide Extended Entry

Such a model is employed to interpret the Stokes vector of different spectral lines, in several sunspots and at different heliocentric angles. This model naturally explains the generation of net circular polarization in sunspots. We find that penumbral flux tubes are rather vertical and hot in the inner penumbra, but become more horizontal and cool further away. We will also argue that the inferred magnetic topology strongly supports the siphon flow mechanism as the driver of the Evershed flow along the penumbral flux tubes. << Hide Extended Entry

The asphericity effects must be expected due to instabilities in thermonuclear burning fronts, rotation of the WD, and interaction with the companion star and the surrounding accretion disk. In this talk, we will present detailed radiation-hydro models, discuss the physical assumptions and present the results which allow to link SN physics with observations with polarization, line profiles and direct imaging as the tell tails. << Hide Extended Entry

There are also increasing evidence indicating that the thermal and compositional structures of the mesosphere and lower thermosphere, as well as gravity wave activities in the middle and upper atmosphere, undergo significant changes during SSW episodes. SSW is thus likely a process that involves couplings from the troposphere to the lower thermosphere on various spatial and temporal scales, and it presents a case to obtain insights into such atmospheric coupling. In this talk, I will discuss several aspects of atmospheric couplings that are relevant to the study of SSW: The amplification of planetary wave(s) prior to SSW; impacts of SSW on the mesosphere and lower thermosphere; possible feedback interactions between the upper and lower atmosphere during SSW; and the general characteristics of chaotic divergence in a whole atmosphere model, which affect the predictability of SSW. << Hide Extended Entry

Earth's magnetosphere and ionosphere form an important linkage between the solar system and the earth system. The magnetosphere stores and subsequently releases the non-radiative solar energies that are carried by the variable solar wind. Because the ionosphere and magnetosphere are intrinsically coupled via magnetic field lines, global distributions of ionospheric electrodynamic fields are closely controlled by plasma processes taking place in the magnetically conjugate regions, such as the location and rate of magnetic reconnection along the dayside magnetopause and in the magnetotail, the energization and precipitation of magnetospheric plasmas, and the thermospheric wind dynamo. This talk will highlight some of the fundamental physical processes of the magnetosphere and ionosphere as well as their role as an "energy regulator" during geomagnetic storms.
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Solar flares may thus be of diminished interest with respect to ionospheric changes driven by the solar wind and magnetosphere, but they do cause enhancements in the high-energy regions of the solar irradiance spectrum that can ionize the upper atmosphere. The question is, are these direct photon effects significant when compared to magnetically-driven disturbances? Recent measurements of the full-disk solar ultraviolet and X-ray spectrum by the SNOE, TIMED, and SORCE satellites during the last solar cycle reveal the intensity and spectra of flares, and recently there have been several spectacular ones that caused measurable changes in the thermosphere/ionosphere system. These time-dependent spectral irradiances can now be used as input conditions to the NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) and other models of thermosphere/ionosphere processes, employing a parameterized energy deposition scheme that includes photoelectron effects. Simulations of the upper atmosphere response to some particularly large flares using these models, as manifested by airglow, ion density, total electron content, temperature, chemical composition, and neutral density changes, are compared to various observational data sets. With certain improvements to the solar data analysis methods, good agreement is obtained between the model simulations and selected atmospheric measurements. This talk summarizes the analysis improvements and model methodology, and shows some comparisons between model output and measurement data. << Hide Extended Entry

While the simulation reproduces many earlier observational results of energy coupling, it also suggests important new implications to the substorm process.

Using simulation runs both with measured solar wind parameters and with idealized solar wind input, we show that the energy transfer rate from the solar wind into the magnetosphere is not a simple function of the IMF and solar wind parameters, but depends on the magnetospheric state and hence also on the past values of the driver. Furthermore, we found a stronger dependence of the energy input on the solar wind dynamic pressure than previous observations would suggest. We discuss how the magnetosphere in part controls the energy input through the magnetopause, and the role of the dynamic pressure in the energy transfer process.

During a simulated substorm, the total dissipation is independent of the amount of growth-phase energy input into the magnetosphere, and the flow of energy through the magnetosphere is quite directly driven by the energy input rate through the magnetopause. While the simulation is not a perfect realization of the multiscale magnetospheric processes, we argue that the essential energy transfer mechanisms are to sufficient accuracy represented by the MHD simulation, and that the main results here are applicable also to the real magnetosphere. This would indicate that the role of the growth phase is to create the configuration change that allows the magnetotail instability to grow. Once the tail is in a state that can accommodate the substorm onset, the expansion phase energy input is quite directly processed by the tail reconnection region and dissipated in the ionosphere. << Hide Extended Entry

New generations of theoretical models have yet to address these new empirical constraints, and recent progress has come from empirical studies of single stars and eclipsing binary systems that contain an evolved primary.

I will review the best spatially resolved semiempirical model of an evolved cool star, zeta Aurigae (K4 Ib + B5 V), for which 2-D line profile computations show a density and velocity structure characterized by a slow wind acceleration, and monitoring of the binary over an orbital cycle with the Very Large Array has confirmed the acceleration and mass-loss rate. This slow acceleration of zeta Aur's wind appears, however, to be at odds with results with the majority of single star semiempirical wind models.

The most significant leap, in the past decade, of our understanding of cool star atmospheres came in 1998 with the discovery by Lim et al., that the bulk of the extended atmosphere of the M2~Iab supergiant Betelgeuse was cool and not at hotter chromospheric temperatures as previously thought. The density structure derived from radio interferometry suggests that this cool plasma is part of the mass outflow. I will present a new analysis of Betelgeuse that reveals the spatial distribution of the electron density and velocity fields in the small filling factor "chromospheric" component that provides new clues to the organization and dynamics of the inhomogeneous atmosphere. On the horizon, the capabilities of the Cosmic Origins Spectrograph, EVLA and ALMA will provide new dynamic and thermodynamic information on a meaningful sample of stellar winds. << Hide Extended Entry