A5015019188- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Solar Radiation and Photovoltaics
- Earthquake Detection and Analysis
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Spacecraft Design and Technology
- CCD and CMOS Imaging Sensors
- Magnetic confinement fusion research
- Adaptive optics and wavefront sensing
- Planetary Science and Exploration
- History and Developments in Astronomy
- solar cell performance optimization
- Space exploration and regulation
- Atomic and Molecular Physics
- Spacecraft and Cryogenic Technologies
- Astrophysics and Star Formation Studies
- Photocathodes and Microchannel Plates
- Electron and X-Ray Spectroscopy Techniques
- Geological and Geophysical Studies
- Tropical and Extratropical Cyclones Research
Queen Mary University of London
2024
Michael E. DeBakey VA Medical Center
2024
MedStar Health
2024
The University of Texas Health Science Center at Houston
2024
Goddard Space Flight Center
2011-2020
Heliophysics
2007-2020
Heliophysics Science Division
2008-2010
Incyte (United States)
2008
University of America
2004
Catholic University of America
2004
The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) is a five telescope package, which has been developed for the Solar Terrestrial Relation Observatory (STEREO) mission by Naval Research Laboratory (USA), Lockheed Astrophysics Goddard Space Flight Center University of Birmingham (UK), Rutherford Appleton Max Planck Institute System (Germany), Centre Spatiale de Leige (Belgium), Institut d'Optique (France) d'Astrophysique (France). SECCHI comprises telescopes, together...
The imaging telescope on board the Transition Region and Coronal Explorer (TRACE) spacecraft observed decaying transversal oscillations of a long [(130 +/- 6) x 10(6) meters], thin [diameter (2.0 0.36) bright coronal loop in 171 angstrom Fe(IX) emission line. were excited by solar flare adjacent active region. decay time is 14.5 2.7 minutes for an oscillation with frequency 3.90 0.13 millihertz. dissipation coefficient estimated to be eight nine orders magnitude larger than theoretically...
view Abstract Citations (234) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Heating of the Solar Corona by Resonant Absorption Alfven Waves Davila, Joseph M. An improved method for calculating resonance absorption heating rate is discussed and results are compared with observations in solar corona. To accomplish this, wave equation a dissipative, compressible plasma derived from linearized magnetohydrodynamic equations transverse speed...
We report on the detection of EUV wave reflection from a coronal hole, as observed by Solar Terrestrial Relations Observatory mission. The was associated with mass ejection (CME) erupting near disk center. It possible to measure kinematics reflected waves for first time. were generally slower than direct wave. One important implications is that transients are truly phenomenon. has CME propagation, especially during declining phase solar cycle when there many low-latitude holes.
The first evidence of transverse oscillations a multistranded loop with growing amplitudes and internal coupling observed by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory is presented. oscillation event occurred 2011 March 8, triggered coronal mass ejection (CME). multiwavelength analysis reveals presence multithermal strands in oscillating loop, whose dynamic behaviors are temperature-dependent, showing differences their amplitudes, phases, emission evolution....
Abstract. Coronal Mass ejections (CMEs) are enormous eruptions of magnetized plasma expelled from the Sun into interplanetary space, over course hours to days. They can create major disturbances in medium and trigger severe magnetic storms when they collide with Earth's magnetosphere. It is important know their real speed, propagation direction 3-D configuration order accurately predict arrival time at Earth. Using data SECCHI coronagraphs onboard STEREO mission, which was launched October...
We report on the 2012 May 17 Ground Level Enhancement (GLE) event, which is first of its kind in Solar Cycle 24. This GLE event to be fully observed close surface by Terrestrial Relations Observatory (STEREO) mission. determine coronal mass ejection (CME) height at start associated metric type II radio burst (i.e., shock formation height) as 1.38 Rs (from Sun center). The CME time particle release was directly measured from a STEREO image 2.32 Rs, agrees well with estimation kinematics....
The Spectral Imaging of the Coronal Environment (SPICE) instrument is a high-resolution imaging spectrometer operating at extreme ultraviolet (EUV) wavelengths. In this paper, we present concept, design, and pre-launch performance facility on ESA/NASA Solar Orbiter mission. goal paper to give prospective users better understanding possible types observations, data acquisition, sources that contribute instrument's signal. discusses science objectives, with focus SPICE-specific aspects, before...
view Abstract Citations (166) References (65) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Measuring Active and Quiet-Sun Coronal Plasma Properties with Extreme-Ultraviolet Spectra from SERTS Brosius, Jeffrey W. ; Davila, Joseph M. Thomas, Roger J. Monsignori-Fossi, Brunella C. We obtained high-resolution extreme-ultraviolet (EUV) spectra of solar active regions, quiet-Sun areas, off-limb areas during 1991 May 7 1993 August 17 flights NASA/Goddard Space...
During relatively quiet solar conditions throughout the spring and summer of 2007, SECCHI HI2 white-light telescope on STEREO B solar-orbiting spacecraft observed a succession wave fronts sweeping past Earth. We have compared these heliospheric images with in situ plasma magnetic field measurements obtained by near-Earth spacecraft, we found near perfect association between occurrence waves arrival density enhancements at leading edges high-speed wind streams. Virtually all strong corotating...
We present three-dimensional reconstructions of coronal mass ejections (CMEs), which were obtained through polarization analysis single-view images recorded with the use Large Angle and Spectrometric Coronagraph (LASCO) C2 coronagraph on board Solar Heliospheric Observatory (SOHO) spacecraft. Analysis a loop-like CME shows complex structure centered at 40 degrees from plane sky, moving radially 250 kilometers/second. Reconstruction two halo CMEs suggests that these events are expanding loop arcades.
We report the first observation of multiple-periodic propagating disturbances along a fan-like coronal structure simultaneously detected in both intensity and Doppler shift Fe XII 195 A line with EUV Imaging Spectrometer (EIS) onboard Hinode. new application seismology is provided based on this observation. analyzed EIS sit-and-stare mode oscillations using running difference wavelet techniques. Two harmonics periods 12 25 min are detected. measured amplitude 1-2 km/s, relative 3%-5%...
Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel unprecedented measurements the solar atmosphere inner heliosphere. To take full advantage these new datasets, tools techniques must developed ease multi-instrument multi-spacecraft studies. In particular currently inaccessible low corona below two radii can only observed remotely. Furthermore used retrieve coronal plasma properties time three...
The time-dependent linearized magnetohydrodynamics (MHD) equations for a fully compressible, low-beta, viscoresistive plasma are solved numerically using an implicit integration scheme. full viscosity stress tensor (Braginskii 1965) is included with the five parameters eta(sub i) i = 0 to 4. In agreement previous studies, numerical simulations demonstrate that dissipation on inhomogeneities in background Alfven speed occurs narrow resonant layer. For active region solar corona values of o)...
view Abstract Citations (83) References (6) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Effects of particle drift on the transport cosmic rays. IV - More realistic diffusion coefficients Jokipii, J. R. ; Davila, M. Results from numerical simulations cosmic-ray modulations by solar wind are presented which show that scattering mean free path should be larger than gyroradius in average magnetic field. It is found difference between and no-drift solutions...
We describe here a method to obtain the position of coronal moving feature in three-dimensional coordinate system based on height – time measurements applied STEREO data. By using diagrams from two SECCHI-COR1 coronagraphs onboard STEREO, one can easily determine direction propagation mass ejection (i.e., if plasma is oriented toward or away Earth). This may prove be useful tool for space weather forecasting by identifying as well real speed ejections.
We present the first Hinode/EUV Imaging Spectrometer observations of 5 minute quasi-periodic oscillations detected in a transition-region line (He ii) and five coronal lines (Fe x, Fe xii, xiii, xiv, xv) at footpoint loop. The exist throughout whole observation, characterized by series wave packets with nearly constant period, typically persisting for 4–6 cycles lifetime 20–30 minutes. There is an approximate in-phase relation between Doppler shift intensity oscillations. This provides...
We present a study of the 2014 January 6 solar energetic particle event which produced small ground level enhancement (GLE), making it second GLE this unusual cycle 24. This was primarily observed by South Pole neutron monitors (increase ∼2.5%) while few other recorded smaller increases. The associated coronal mass ejection (CME) originated behind western limb and had speed 1960 km s−1. height CME at start metric type II radio burst, indicates formation strong shock, measured to be 1.61 Rs...
Goddard Space Flight Center's Solar EUV Rocket Telescope and Spectrograph was flown on 1995 May 15 (SERTS-95), carrying a multilayer-coated toroidal diffraction grating that enhanced the instrumental sensitivity in its second-order wave band (171-225 Å). Spectra spectroheliograms of NOAA active region 7870 (N09 W22) were obtained this with spectral resolution (instrumental FWHM) ~30 mÅ first-order (235-335 Å) ~55 mÅ. quiet-Sun areas northeast also obtained. We derived SERTS-95 relative...
We present the first model of resonant heating coronal loops that incorporates dependence loop density on rate. By adopting quasi-static equilibrium scaling law ρ ∝ Q5/7, where is and Q volumetric rate, we are able to approximate well-known phenomena chromospheric evaporation condensation, which regulate density. combine this with a quasi-nonlinear MHD for absorption Alfvén waves in order study spatial temporal heating. find concentrated multiple resonance layers, rather than single layer...