27 Result(s)
within
Carolus J. Schrijver
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Article
Open AccessExtreme solar events
We trace the evolution of research on extreme solar and solar-terrestrial events from the 1859 Carrington event to the rapid development of the last twenty years. Our focus is on the largest observed/inferred/...
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Open AccessThe Characteristics of Solar X-Class Flares and CMEs: A Paradigm for Stellar Superflares and Eruptions?
This paper explores the characteristics of 42 solar X-class flares that were observed between February 2011 and November 2014, with data from the Solar Dynamics Observatory (SDO) and other sources. This flare lis...
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Publication Statistics on the Sun and the Heliosphere
The professional literature provides means to review the evolution and geographic distribution of the scientific communities engaged in solar and heliospheric physics. With the help of the Astrophysics Data Sy...
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A Statistical Study of Distant Consequences of Large Solar Energetic Events
Large solar flares and eruptions may influence remote regions through perturbations in the outer-atmospheric magnetic field, leading to causally related events outside of the primary or triggering eruptions th...
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Blind Stereoscopy of the Coronal Magnetic Field
We test the feasibility of 3D coronal-loop tracing in stereoscopic EUV image pairs, with the ultimate goal of enabling efficient 3D reconstruction of the coronal magnetic field that drives flares and coronal m...
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Automated Temperature and Emission Measure Analysis of Coronal Loops and Active Regions Observed with the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (SDO/AIA)
We developed numerical codes designed for automated analysis of SDO/AIA image datasets in the six coronal filters, including: i) coalignment test between different wavelengths with measurements of the altitude of...
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Open AccessThe Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO)
The Atmospheric Imaging Assembly (AIA) provides multiple simultaneous high-resolution full-disk images of the corona and transition region up to 0.5 R ⊙ above the solar limb with 1.5-arcse...
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The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO)
The Atmospheric Imaging Assembly (AIA) provides multiple simultaneous high-resolution full-disk images of the corona and transition region up to 0.5 R ⊙ above the solar limb with 1.5-arcsec spatial re...
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Article
The Stellar Imager (SI) project: a deep space UV/Optical Interferometer (UVOI) to observe the Universe at 0.1 milli-arcsec angular resolution
The Stellar Imager (SI) is a space-based, UV/Optical Interferometer (UVOI) designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and of the Universe in general. It will also probe v...
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The Global Solar Magnetic Field Through a Full Sunspot Cycle: Observations and Model Results
Based on 11 years of SOHO/MDI observations from the cycle minimum in 1997 to the next minimum around 2008, we compare observed and modeled axial dipole moments to better understand the large-scale transport pr...
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Open AccessNonlinear Force-Free Modeling of Coronal Magnetic Fields. II. Modeling a Filament Arcade and Simulated Chromospheric and Photospheric Vector Fields
We compare a variety of nonlinear force-free field (NLFFF) extrapolation algorithms, including optimization, magneto-frictional, and Grad – Rubin-like codes, applied to a solar-like reference model. The model ...
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Nonlinear Force-Free Modeling of Coronal Magnetic Fields Part I: A Quantitative Comparison of Methods
We compare six algorithms for the computation of nonlinear force-free (NLFF) magnetic fields (including optimization, magnetofrictional, Grad–Rubin based, and Green's function-based methods) by evaluating thei...
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Photospheric and heliospheric magnetic fields
The magnetic field in the heliosphere evolves in response to the photospheric field at its base. This evolution, together with the rotation of the Sun, drives space weather through the continually changing con...
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The topology of a mixed-polarity potential field, and inferences for the heating of the quiet solar corona
We study the statistical properties of the connectivity of the corona over the quiet Sun by analyzing the potential magnetic field above the central area of source planes sprinkled randomly with some 300 magne...
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Transverse oscillations in coronal loops observed with TRACE – I. An Overview of Events, Movies, and a Discussion of Common Properties and Required Conditions
We study transverse loop oscillations triggered by 17flares and filament destabilizations; only 2 such cases have been reported in the literature until now. Oscillation periods are estimated to range over a fa...
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Transverse Oscillations in Coronal Loops Observed with TRACE – II. Measurements of Geometric and Physical Parameters
We measure geometric and physical parameters oftransverse oscillations in 26 coronal loops, out of the 17 events described in Paper I by Schrijver, Aschwanden, and Title (2002). These events, lasting from 7 to...
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Catastrophic cooling and high-speed downflow in quiescent solar coronal loops observed with TRACE
Observations with the Transition Region and Coronal Explorer, TRACE, show frequent catastrophic cooling and evacuation of quiescent solar coronal loops over active regions. We analyze this process using image ...
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Does Magnetic Flux Submerge at Flux Cancelation Sites?
Simultaneous measurements of the magnetic fields in the photosphere and chromosphere were used to investigate if magnetic flux is submerging at sites between adjacent opposite polarity magnetic network element...
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Does Magnetic Flux Submerge at Flux Cancelation Sites?
Simultaneous measurements of the magnetic fields in the photosphere and chromosphere were used to investigate if magnetic flux is submerging at sites between adjacent opposite polarity magnetic network element...
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Active regions losing their moorings by subsurface reconnection
The properties of emerging active regions suggest that they originate from deep flux bundles with a field strength well above the equipartition value, so that they can resist strong deformation by convection a...
