A5082262420- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Radiation Therapy and Dosimetry
- Stellar, planetary, and galactic studies
- Solar Radiation and Photovoltaics
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Radio Astronomy Observations and Technology
- Planetary Science and Exploration
- Astrophysics and Cosmic Phenomena
- Atmospheric Ozone and Climate
- Spaceflight effects on biology
- Radioactivity and Radon Measurements
- Radiation Dose and Imaging
- CCD and CMOS Imaging Sensors
- Photovoltaic System Optimization Techniques
- Spacecraft Design and Technology
- Graphite, nuclear technology, radiation studies
- Cardiovascular Health and Disease Prevention
- Space Science and Extraterrestrial Life
- Spacecraft and Cryogenic Technologies
- Superconducting Materials and Applications
Institute of Astronomy and National Astronomical Observatory
2017-2024
Bulgarian Academy of Sciences
2021
Curtin University
2018
Center for Astrophysics Harvard & Smithsonian
2012-2017
Smithsonian Astrophysical Observatory
2014-2017
New Jersey Institute of Technology
2014
National Oceanic and Atmospheric Administration
2014
John Wiley & Sons (United States)
2014
University of Michigan–Ann Arbor
2014
Boston University
2009-2013
Solar Energetic Particle (SEP) events are interesting from a scientific perspective as they the product of broad set physical processes corona out through extent heliosphere, and provide insight into particle acceleration transport that widely applicable in astrophysics. From operations perspective, SEP pose radiation hazard for aviation, electronics space, human space exploration, particular missions outside Earth's protective magnetosphere including to Moon Mars. Thus, it is critical...
[1] We review NASA's short-term and career radiation limits for astronauts methods their application to future exploration missions outside of low Earth orbit. Career are intended restrict late occurring health effects include a 3% risk exposure-induced death from cancer new central nervous system heart disease risks. Short-term dose used prevent in-flight sickness or through restriction the doses blood forming organs clinically significant cataracts skin damage lens limits, respectively....
We derive kinematic properties for two recent solar coronal transient waves observed off the western limb with Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO) mission. The occurred over $\sim10$-min intervals on consecutive days - June 12 and 13, 2010. For first time, off-limb are imaged a high 12-sec cadence, making possible detailed analysis of these transients in low corona between $\sim1.1$-2.0 radii ($R_{s}$). use observations 193 211 {\AA} AIA channels to...
[1] We are preparing to return humans the Moon and setting stage for exploration Mars beyond. However, it is unclear if long missions outside of low-Earth orbit can be accomplished with acceptable risk. The central objective a new modeling project, Earth-Moon-Mars Radiation Exposure Module (EMMREM), develop validate numerical module characterizing time-dependent radiation exposure in interplanetary space environments. EMMREM being designed broad use by researchers predict integrating over...
The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) measures linear energy transfer by Galactic Rays (GCRs) and Solar Energetic Particles (SEPs) on Lunar Reconnaissance Orbiter (LRO) Mission in a circular, polar lunar orbit. GCR fluxes remain at highest levels ever observed during space age. One largest SEP events CRaTER LRO mission occurred June 7, 2011. We compare model predictions Earth‐Moon‐Mars Environment Module (EMMREM) both dose rates from GCRs SEPs this event with results...
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...
We present a study on particle acceleration in the low corona associated with expansion and of coronal mass ejections (CMEs). Because CME regions are effective accelerators over finite spatial region, we show that there is rigidity regime where particles effectively diffuse away escape from sites using analytic solutions to Parker transport equation. This leads formation broken power-law distributions. Based our solutions, find natural ordering break energy second slope (above energy) as...
The Parker Solar Probe (PSP) mission provides a unique opportunity for both remote and in situ measurements of solar activity very close to the Sun. This is an especially powerful approach when studying radio bursts, which can also be observed with modern ground-based interferometers such as Low Frequency Array (LOFAR). We report here combined detection energetic electrons (LOFAR) telescope PSP during its 17th perihelion encounter, on September 24, 2023. LOFAR short but intense period type...
The dynamic behavior of solar prominences and filaments is a preursor to coronal mass ejections (CMEs), which can disrupt Earth's magnetosphere affect satellite communications. Systematic ground-based observations, conducted with high temporal resolution, are instrumental in monitoring these structures. Analysis the morphological changes destabilization processes captured datasets help identify early warning signs potential eruptions. This capability vital for developing reliable space...
Abstract Radio emission of the quiet Sun is considered to be due thermal bremsstrahlung hot solar atmosphere. The properties in microwave band have been well studied, and they can described by spectrum emission. In meter-wave decameter-wave bands, rarely studied instrumental limitations. this work, we use LOw Frequency ARray telescope perform high quality interferometric imaging spectroscopy observations coronal at frequencies below 90 MHz. We present brightness temperature size frequency...
We investigate the ionospheric effects of a solar energetic particle (SEP) event at Mars, specifically 29 September 1989 event. use its energy spectrum and steady state model to simulate vertical profiles ion electron densities. The response this large would have been readily observable. It caused densities exceed 10 4 cm −3 30–170 km, much larger than typically observed below 100 km. also increased ionosphere's total content by half subsolar value strong attenuation radio waves. simulated...
The acceleration of protons and electrons to high (sometimes GeV/nucleon) energies by solar phenomena is a key component space weather. These energetic particle (SEP) events can damage spacecraft communications, as well present radiation hazards humans. In-depth simulations have been performed for idealized magnetic fields diffusive propagation, at the same time quality MHD coronal mass ejections (CMEs) has improved significantly. However, date these two pieces puzzle remained largely...
Coronal mass ejections (CMEs) are thought to drive collisionless shocks in the solar corona, which turn have been shown capable of accelerating energetic particles (SEPs) minutes. It has notoriously difficult extract information about particle spectra due lack in-situ measurements. is possible, however, combine remote observations with data-driven models order deduce coronal shock properties relevant local acceleration SEPs and their heliospheric connectivity near-Earth space. We present...
[1] Galactic cosmic rays (GCRs) are extremely difficult to shield against and pose one of the most severe long-term hazards for human exploration space. The recent solar minimum between cycles 23 24 shows a prolonged period reduced activity low interplanetary magnetic field strengths. As result, modulation GCRs is very weak, fluxes near their highest levels in last 25 years fall 2009. Here we explore dose rates current make predictions Lunar Reconnaissance Orbiter (LRO) Cosmic Ray Telescope...
[1] The instrument payload aboard the 2001 Mars Odyssey orbiter includes several instruments that are sensitive to energetic charged particles from galactic cosmic rays (GCR) and solar particle events (SPE). Martian Radiation Environment Experiment (MARIE) was a dedicated spectrometer, but it ceased functioning during large storm of October/November 2003. Data two other used here: Gamma Ray Spectrometer scintillator component High Energy Neutron Detector. Though not primarily designed...
[1] The Earth-Moon-Mars Radiation Environment Module (EMMREM) is a comprehensive numerical framework for characterizing and predicting the radiation environment of inner heliosphere. We present study October/November 2003 Halloween solar energetic particle events with an acceleration propagation model that part EMMREM, highlighting current ability to make predictions at various locations compare Ulysses observations protons energies above 10 MeV in order obtain realistic proton fluxes...
Key Points Radiation from low corona Prompt SEP events CME Large doses in 2 h
Mitigating the lethal threats caused by coronal mass ejections (CMEs) on human and space operations can be accomplished with a fast accurate forecast of Earth-directed CME transit times. The current paper presents robust Cascade Forward Neural Network (CFNN) framework to predict times halo CMEs using total 290 CME/Interplanetary (ICME) pairs datasets for past two half decades (solar cycle; SC 23, 24, 25). It is first time incorporating deprojected speeds into machine learning mitigate...
The solar corona between below 10 radii is an important region for early acceleration and transport of energetic particles (SEPs) by coronal mass ejection-driven shock waves. There, these waves propagate into a highly variable dynamic medium with steep gradients rapidly expanding magnetic fields, which modulates the particle near shock/wave surfaces, way SEPs spread heliosphere. We present study modeling in global events corona, as well their to 1 au, based on telescopic observations coupled...
[1] Solar energetic particles (SEPs) provide a significant radiation hazard for manned and unmanned interplanetary (IP) space missions. In order to estimate these hazards, it is essential quantify the gradients of SEP intensities in IP medium. The Earth-Moon-Mars Radiation Exposure Module (EMMREM) new project aimed at characterizing time-dependent exposure space. this paper, we utilize EMMREM study radial dependence proton peak intensities, event fluences, dose equivalents 27–31 May 2003...
Coronal bright fronts (CBF) are large-scale wavelike disturbances in the solar corona, related to eruptions. They observed (mostly extreme ultraviolet (EUV) light) as transient of finite width, propagating away from eruption source location. Recent studies individual eruptive events have used EUV observations CBFs and metric radio type II burst show intimate connection between waves low corona coronal mass ejection (CME)-driven shocks. imaging with atmospheric assembly instrument on dynamics...
Abstract An outstanding problem in heliospheric physics is understanding the acceleration of solar energetic particles (SEPs) coronal mass ejections (CMEs) and flares. A fundamental question whether occurs interplanetary space or near Sun. Recent work has shown that CME-driven shocks may produce SEPs while still below five radii. In this we explore SEP during onset CMEs even lower corona, using realistic suprathermal spectra, for a selection events. We have calculated quiet-time, pre-event...
ABSTRACT Radio spectroscopy provides a unique inspection perspective for solar and space weather research, which can reveal the plasma energetic electron information in corona inner heliosphere. However, radio-frequency interference (RFI) from human activities affects sensitive radio telescopes, significantly quality of observation. Thus, RFI detection mitigation observations is necessary to obtain high science-ready data. The flagging particularly challenging at low frequency, because...
Energetic storm particle (ESP) events are enhancements above ∼0.05 MeV/nucleon ions near 1 AU in association with the passage of an interplanetary (IP) coronal mass ejection (ICME). The primary candidate producing these is diffusive shock acceleration (DSA). ESPs can produce significant increases near-Earth particulate radiation and pose severe hazards to astronauts hardware space. Physical parameters thought affect ESP production include IP properties (e.g., speed, strength, obliquity)...