A5000417828- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Solar Radiation and Photovoltaics
- Gamma-ray bursts and supernovae
- Spacecraft Design and Technology
- Astronomy and Astrophysical Research
- Earthquake Detection and Analysis
- Astrophysics and Star Formation Studies
- Characterization and Applications of Magnetic Nanoparticles
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Energy Load and Power Forecasting
- Space Satellite Systems and Control
- Geophysical and Geoelectrical Methods
- Spacecraft and Cryogenic Technologies
- Space Exploration and Technology
- Cardiac Imaging and Diagnostics
- Scientific Computing and Data Management
- Insurance, Mortality, Demography, Risk Management
- Traffic Prediction and Management Techniques
GeoSphere Austria
2023-2025
Space Research Institute
2014-2024
Austrian Academy of Sciences
2014-2023
Central Institution for Meteorology and Geodynamics
2022-2023
Graz University of Technology
2020-2022
University of Graz
2009-2021
Munich University of Applied Sciences
2016
George Mason University
2015
University of California, Berkeley
2012-2014
University of California System
2012-2013
Abstract The severe geomagnetic effects of solar storms or coronal mass ejections (CMEs) are to a large degree determined by their propagation direction with respect Earth. There is lack understanding the processes that determine non-radial propagation. Here we present synthesis data from seven different space missions fast CME, which originated in an active region near disk centre and, hence, significant impact was forecasted. However, CME demonstrated be channelled during eruption into...
Abstract Accurate forecasting of the properties coronal mass ejections (CMEs) as they approach Earth is now recognized an important strategic objective for both NOAA and NASA. The time arrival such events a key parameter, one that had been anticipated to be relatively straightforward constrain. In this study, we analyze forecasts submitted Community Coordinated Modeling Center at NASA's Goddard Space Flight over last 6 years answer following questions: (1) How well do these models forecast...
We study the interaction of two successive coronal mass ejections (CMEs) during 2010 August 1 events using STEREO/SECCHI COR and HI data. obtain direction motion for both CMEs by applying several independent reconstruction methods find that head in similar directions. This provides evidence a full takes place between can be observed HI1 field-of-view. The de-projected kinematics faster CME from Sun to Earth is derived combining remote observations with situ measurements at AU. speed profile...
Since the advent of wide-angle imaging inner heliosphere, a plethora techniques have been developed to investigate three-dimensional structure and kinematics solar wind transients, such as coronal mass ejections, from their signatures in single- multi-spacecraft observations. These techniques, which range highly complex computationally intensive methods based on simple curve fitting, all inherent advantages limitations. In analysis single-spacecraft observations, much use has made fixed ϕ...
Forecasting the in situ properties of coronal mass ejections (CMEs) from remote images is expected to strongly enhance predictions space weather, and general interest for studying interaction CMEs with planetary environments. We study feasibility using a single heliospheric imager (HI) instrument, imaging solar wind density Sun 1 AU, connecting observations CMEs. compare speed arrival time 22 (in 2008-2012) corresponding interplanetary ejection (ICME) parameters at observatories (STEREO...
In 2010 May 23–24, Solar Dynamics Observatory (SDO) observed the launch of two successive coronal mass ejections (CMEs), which were subsequently tracked by SECCHI suite on board STEREO. Using COR2 coronagraphs and heliospheric imagers (HIs), initial direction both CMEs is determined to be slightly west Sun–Earth line. We derive CME kinematics, including evolution expansion until 0.4 AU. find that, during interaction, second decelerates from a speed above 500 km s−1 380 s−1, leading edge...
The successive coronal mass ejections (CMEs) from 2010 July 30 - August 1 present us the first opportunity to study CME-CME interactions with unprecedented heliospheric imaging and in situ observations multiple vantage points. We describe two cases of CME interactions: merging CMEs launched close time overtaking a preceding by shock wave. on interact Sun form merged front, which then overtakes near AU, as revealed wide-angle observations. Connections between signatures at AU suggest that...
We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between Sun Earth, a key question in CME research space weather forecasting. Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts situ measurements from multiple vantage points. select three events for this study, 2012 January 19, 23, March 7 CMEs. Different previous event studies, work attempts to...
Abstract Interplanetary coronal mass ejections (ICMEs) are a significant feature of the heliospheric environment and primary cause adverse space weather at Earth. ICME propagation evolution magnetic field structure during still not fully understood. We analyze structures 18 flux ropes observed by radially aligned spacecraft in inner heliosphere. Similarity underlying rope is determined through application simple technique that maps profile from one to other. In many cases, show very strong...
On 2020 April 19 a coronal mass ejection (CME) was detected in situ by Solar Orbiter at heliocentric distance of about 0.8 AU. The CME later observed on 20th the Wind and BepiColombo spacecraft whilst located very close to Earth. This presents good opportunity for triple radial alignment study, as were separated less than 5$^\circ$ longitude. source CME, which launched 15th, an almost entirely isolated streamer blowout. STEREO-A event remotely from -75.1$^\circ$ longitude, is exceptionally...
Abstract We report the result of first search for multipoint in situ and imaging observations interplanetary coronal mass ejections (ICMEs) starting with Solar Orbiter (SolO) data 2020 April–2021 April. A exploration analysis is performed including visualizations magnetic-field plasma made by five spacecraft SolO, BepiColombo, Parker Probe (PSP), Wind, STEREO-A, connection coronagraph heliospheric from STEREO-A/SECCHI SOHO/LASCO. identify ICME events that could be unambiguously followed...
Abstract Coronal mass ejections (CMEs) are large-scale eruptions with a typical radial size at 1 au of 0.21 but their angular width in interplanetary space is still mostly unknown, especially for the magnetic ejecta (ME) part CME. We take advantage STEREO-A separation 20°–60° from Sun–Earth line 2020 October to 2022 August, and perform two-part study constrain MEs ecliptic plane: (a) we all CMEs that observed remotely propagate between Sun–STEREO-A lines determine how many impact one or both...
Abstract Coronal mass ejections (CMEs) can create significant disruption to human activities and systems on Earth, much of which be mitigated with prior warning the upstream solar wind conditions. However, it is currently extremely challenging accurately predict arrival time internal structure a CME from coronagraph images alone. In this study, we take advantage rare opportunity use Solar Orbiter, at 0.5 au as an monitor. combination low‐latency STEREO‐A, successfully predicted two events...
<i>Context. <i/>The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast their arrival on Earth is one central issues space weather studies.<i>Aims. <i/>We investigate to which degree various ICME parameters (mass, size, take-off speed) ambient solar-wind (density velocity) affect Sun-Earth transit time.<i>Methods. study solutions a drag-based equation motion by systematically varying input parameters. The analysis focused times 1 AU velocities.<i>Results. model...
We examine the implications of widely used, force‐free, constant‐ α flux rope model interplanetary magnetic clouds for evolution these mesoscale (fraction 1 AU) structures in heliosphere, with special emphasis on inner (≤1 heliosphere. employ primarily events observed by Helios and 2 probes between 0.3 AU ascending maximum phases solar cycle 21 Wind at a similar phase activity cycle. supplement data observations from other spacecraft (e.g., Voyagers 2, Pioneers 10 11, others). Our set...
We study three CME/ICME events (2008 June 1-6, 2009 February 13-18, 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of STEREO Heliospheric Imagers and situ plasma magnetic field measurements. focus on the ICME propagation IP space that is governed by two forces, propelling Lorentz force drag force. address question at which heliospheric distance range becomes dominant CME gets adjusted solar wind flow. To this aim we analyze speed differences between ICMEs ambient...
Real-time forecasting of the arrival coronal mass ejections (CMEs) at Earth, based on remote solar observations, is one central issues space-weather research. In this paper, we compare arrival-time predictions calculated applying numerical "WSA-ENLIL+Cone model" and analytical "drag-based (DBM). Both models use coronagraphic observations CMEs as input data, thus providing an early forecast two to four days before disturbance depending CME speed. It shown that both methods give very similar...
We present multi-point in situ observations of a complex sequence coronal mass ejections (CMEs) which may serve as benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various missions, Solar Dynamics Observatory/Solar Heliospheric Observatory/Solar-TErrestrial-RElations-Observatory (SDO/SOHO/STEREO), monitored several CMEs originating within tens degrees from the solar disk center. compare their imprints four widely separated...
The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This led to development numerous stereoscopic techniques investigate three-dimensional structure kinematics wind transients such as coronal mass ejections (CMEs). Two methods—triangulation tangent a sphere—can be used determine time profiles propagation direction radial distance (and thereby speed) transient it travels through heliosphere,...
On 2010 August 1, the northern solar hemisphere underwent significant activity that involved a complex set of active regions near central meridian with, nearby, two large prominences and other more distant regions. This culminated in eruption four major coronal mass ejections (CMEs), effects which were detected at Earth system bodies. Recognizing unprecedented wealth data from wide range spacecraft available—providing potential for us to explore methods CME identification tracking, assess...
We present an advance towards accurately predicting the arrivals of coronal mass ejections (CMEs) at terrestrial planets, including Earth. For first time, we are able to assess a CME prediction model using data over 2/3 solar cycle observations with Heliophysics System Observatory. validate modeling results 1337 CMEs observed Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years by 5 in situ observing spacecraft. use self-similar expansion for...
In this study, we present a new method for forecasting arrival times and speeds of coronal mass ejections (CMEs) at any location in the inner heliosphere. This approach enables adoption highly flexible geometrical shape CME front with an adjustable angular width radius curvature its leading edge, i.e., assumed geometry is elliptical. Using, as input, Solar TErrestrial RElations Observatory (STEREO) heliospheric imager (HI) observations, elliptic conversion (ElCon) introduced combined use...