A5075355111- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Complex Systems and Time Series Analysis
- Earthquake Detection and Analysis
- Solar Radiation and Photovoltaics
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Statistical Mechanics and Entropy
- Magnetic confinement fusion research
- Theoretical and Computational Physics
- Oil, Gas, and Environmental Issues
- Astrophysics and Cosmic Phenomena
- Global Energy and Sustainability Research
- Adaptive optics and wavefront sensing
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Advanced Thermodynamics and Statistical Mechanics
- Astrophysical Phenomena and Observations
- Neural Networks and Applications
- Vasculitis and related conditions
- Cosmology and Gravitation Theories
- History and Developments in Astronomy
University Hospital of Basel
2001-2025
Lockheed Martin (Canada)
2005-2024
Lockheed Martin (United States)
2013-2023
Deleted Institution
2019
Star Technology and Research (United States)
2015
Lockheed Martin (Australia)
2007-2014
Rice University
2010-2011
University of Maryland, College Park
1992-2008
Lockheed Martin (United Kingdom)
2003-2007
University of California, Irvine
2002
We report here, for the first time, on spatial oscillations of coronal loops, which were detected in extreme-ultraviolet wavelengths (171 Å) with Transition Region and Coronal Explorer, temperature range Te ≈ 1.0-1.5 MK. The observed loop occurred during a flare that began at 1998 July 14, 12:55 UT are most prominent 20 minutes. oscillating loops connect penumbra leading sunspot to site trailing portion. identified five an average length L = 130,000 ± 30,000 km. transverse amplitude is A...
Nonlinear force-free field (NLFFF) models are thought to be viable tools for investigating the structure, dynamics and evolution of coronae solar active regions. In a series NLFFF modeling studies, we have found that successful in application analytic test cases, relatively when applied numerically constructed Sun-like but they less real data. Different been markedly different line configurations provide widely varying estimates magnetic free energy coronal volume, require consistent, vector...
Shortly after the seminal paper {\sl "Self-Organized Criticality: An explanation of 1/f noise"} by Bak, Tang, and Wiesenfeld (1987), idea has been applied to solar physics, in "Avalanches Distribution Solar Flares"} Lu Hamilton (1991). In following years, an inspiring cross-fertilization from complexity theory astrophysics took place, where SOC concept was initially flares, stellar magnetospheric substorms, later extended radiation belt, heliosphere, lunar craters, asteroid Saturn ring,...
We present a detailed analysis of the geometric and physical parameters 281 EUV nanoflares, simultaneously detected with TRACE telescope in 171 195 Å wavelengths. The detection discrimination these flarelike events is first paper this series. determine loop length l, width w, emission measure EM, evolution electron density ne(t) temperature Te(t), flare decay time τdecay, calculate radiative loss τloss, conductive τcond, thermal energy Eth. findings are as follows: (1) nanoflares range...
The temperature Te(s) and density structure ne(s) of active region loops in EUV observed with TRACE is modeled a multithread model, synthesized from the summed emission many loop threads that have distribution maximum temperatures satisfy steady state Rosner-Tucker-Vaiana (RTV) scaling law, modified by Serio et al. for gravitational stratification (called RTVSp following). In recent Letter, Reale & Peres demonstrated this method can explain almost isothermal appearance (observed Lenz al.) as...
The three-dimensional structure of solar active region NOAA 7986 observed on 1996 August 30 with the Extreme-Ultraviolet Imaging Telescope (EIT) board Solar and Heliospheric Observatory (SOHO) is analyzed. We develop a new method dynamic stereoscopy to reconstruct geometry dynamically changing loops, which allows us determine orientation mean loop plane respect line sight, prerequisite correct properly for projection effects in models. With this filter-ratio technique applied EIT 171 195 Å...
Recent observations of coronal loops in EUV wavelengths with the Transition Region and Coronal Explorer (TRACE) Extreme-Ultraviolet Imaging Telescope (EIT) on Solar Heliospheric Observatory (SOHO) demonstrated three new results that cannot be explained by most existing loop models: (1) are near-isothermal along their segments, (2) they show an overpressure or overdensity compared requirements steady state uniform heating, (3) brightest exhibit extended scale heights up to 4 times hydrostatic...
The damping mechanism of recently discovered coronal loop transverse oscillations provides clues to the heating. We determine scaling time with parameters loops observed in extreme ultraviolet by Transition Region and Coronal Explorer. find excellent agreement power predicted phase mixing poor wave leakage or ideal decay cylindrical kink mode mechanisms. Phase leads rapid dissipation Alfvén waves due variation speed across front formation small scales. Our results suggest that are dissipated...
A detailed analysis of a coronal loop oscillation event is presented, using data from the Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO) for first time. The occurred on 2010 Oct 16, 19:05-19:35 UT, was triggered by an M2.9 GOES-class flare, located inside highly inclined cone narrow-angle CME. This had number unusual features: (i) Excitation kink-mode oscillations in vertical polarization (in plane); (ii) Coupled cross-sectional and density with identical...
We present the first unambiguous detection of quasi-periodic wave trains within broad pulse a global EUV (so-called "EIT wave") occurring on limb. These trains, running ahead lateral CME front 2-4 times slower, coherently travel to distances $>R_{sun}/2$ along solar surface, with initial velocities up 1400 km/s decelerating ~650 km/s. The rapid expansion initiated at an elevated height 110 Mm produces strong downward and compression, which may play important role in driving primary shaping...
Quasi-periodic, propagating fast mode magnetosonic waves in the corona were difficult to observe past due relatively low instrument cadences. We report here evidence of such directly imaged EUV by new SDO AIA instrument. In 2010 August 1 C3.2 flare/CME event, we find arc-shaped wave trains 1-5% intensity variations (lifetime ~200 s) that emanate near flare kernel and propagate outward up ~400 Mm along a funnel coronal loops. Sinusoidal fits typical train indicate phase velocity 2200 +/- 130...
We analyzed the soft X-ray light curves from Geostationary Operational Environmental Satellites over last 37 years (1975–2011) and measured with an automated flare detection algorithm 300,000 solar events (amounting to ≈5 times higher sensitivity than NOAA catalog). find a power-law slope of αF = 1.98 ± 0.11 for (background-subtracted) peak fluxes that is invariant through three cycles agrees theoretical prediction 2.0 fractal-diffusive self-organized criticality (FD-SOC) model. For rise...
<h3>Objective</h3> To define the specificity and extent of duplex sonography (DS) findings suggestive vessel wall inflammation in patients with giant cell arteritis (GCA). <h3>Methods</h3> Patients admitted between December 2006 April 2009 to University Hospital Basel a suspicion GCA were eligible for study. DS 2×11 arterial regions was performed all study participants, American College Rheumatology criteria applied classify into or non-GCA groups. <h3>Results</h3> diagnosed 38 72...