Physical Models of Solar Active Regions and the Solar Spectral Irradiance
Our team of civil servants, on-site contractors, and off-site partners is funded by the Heliophysics Internal Scientist Funding Model (HISFM) program to build state-of-the-art physical models of solar active regions their EUV and X-ray emissions. The spectral irradiance varies on timescales of one to several days and has important space weather impacts as active regions evolve and rotate onto and off of the visible side of the Sun. Coronal heating is the source of the radiant energy, and our work includes detailed investigations into the mechanism(s) of the heating. The new active region modeling effort builds on accomplishments made during our previous HISFM projects. Team activities are closely linked to those of International Space Weather Action Team ISWAT 02-06, which we lead. For more information about the projects being undertaken in the group, please see the funded proposals, progress reports, and presentations listed below.
Publications and External Presentations supported by this and previous work packages:Workpackage Reviews
- 5/16/2023, ISFM Review: Heating of the Magnetically Closed Corona pdf, pptx
- 4/6/2022, ISFM Showcase: Heating of the Magnetically Closed Corona (pptx)
- 3/15/2021, ISFM Showcase: Heating of the Magnetically Closed Corona (pptx)
Upcoming Meetings
- 4/15/2026, Yi-Min Huang, Coronal heating simulation
Presentations given at previous group meetings:
Physical Models of Solar Active Regions and the Solar Spectral Irradiance
- 3/18/2026, Shanwlee Sow Mondal, Deriving Coronal Heating Scaling Laws from 3D MHD Simulations
- 3/4/2026, Aparna Venkataramanasastry, Is Heating in Coronal Loops also governed by Field Advection Speeds?
- 2/18/2026, Vadim Uritsky, Are rotational motions / velocity swirls in the photosphere a significant coronal driver? Part 2: plage analysis, driver model
- 2/4/2026, Sibasish Laha, Coronal X-ray signatures in active galactic nuclei: Observational perspectives and the open questions
- 1/21/2026, Shanwlee Sow Mondal, Nanoflare Energy-Delay Correlation in the Closed Solar Corona
- 1/14/2026, James Leake, The Onset of Magnetic Reconnection in the Solar Corona
- 9/3/2025, Alfred de Wijn, Magnetic Element Motions
- 8/6-8/6/2025, COSPAR ISWAT Team S2-06: Origins of the Spectral Irradiance and its Intermediate Timescale Variability, Meeting Agenda
- 6/25/2025, Terry Kucera, GX Simulator Modeling of AR 12760
- 5/14/2025, Matthias Rempel, Simulations of the Solar Atmosphere with MURaM
- 4/16/2025, Shanwlee Sow Mondal, Characterizing Nanoflare Energy and Frequency through Field Line Analysis
- 4/2/2025, Gelu Nita, Disentangling the Coronal and TR EUV emission by combining EUV and Microwave data with GX Simulator 3d data-constrained modeling
- 3/19/2025, Vadim Uritsky, Are rotational motions/velocity swirls in the horizontal flow a significant coronal driver?
- 3/5/2025, David Pontin, Reconnectipn and Heating in Braided Coronal Loops
- 2/19/2025, Biswajit Mondal, Spatial and Temporal Distribution of Nanoflare Heating during Active Region Evolution
- 2/5/2025, Jim Klimchuk, Processes Creating Clumpy Magnetic Field
- 2/5/2025, Shanwlee Sow Mondal, DEMs from Models
- 2/5/2025, Peter Young, Data based DEMs from Active Regions
- 11/13/2024, Aisha Iyer, Brett Morris, Sarah Peacock, & Allison Youngblood, Motivation and constraints from stellar astrophysics
- 10/30/2024, Terry Kucera, AR 12760: ISWAT region
- 10/30/2024, Kalman Knizhnik, Reconnection in terribly resolved dynamically driven current sheets
Heating of the Magnetically Closed Corona
- 9/11/2024, Jim Klimchuk, Sherry Chhabra & Craig Johnston HSD Director's Seminar, Physical Models of Solar Active Regions and the Solar Spectral Irradiance pdf, pptx
- 9/4/2024, James Leake, Reconnection Onset in the Solar Corona
- 8/21/2024, Jenny Marcela Rodriguez Gomez Modeling Solar Spectral Irradiance (SSI) from Iron lines using the COronal DEnsity and Temperature (CODET) model v1.1
- 8/7/2024, Adam Kobelski The MaGIXS rocket experiment
- 7/24/2024, Sam Schonfeld GX Simulator as a tool for studying coronal heating and solar irradiance
- 4/17/2024, Irina Kitiashvili 3D Radiative MHD Modeling of Subsurface Dynamics and Atmosphere of the Sun and Links to Coronal Heating
- 4/3/2024, Will Barnes synthesizAR: A Python framework for forward-modeling optically-thin emission from field-aligned hydrodynamic models
- 3/20/2024, Joe Plowman Coronal 3D Reconstruction with CROBAR
- 3/6/2024, Jim Klimchuk Observable Constraints on Models
- 3/6/2024, Terry Kucera Prepping to Run GX Simulator: Progress Report
- 11/15/2023, Lars Daldorff Solar Convection
- 11/1/2023, Antoine Dolliou Campfires
- 10/18/2023, Joshua Pettit Atmospheric Impacts of X-ray and EUV Irradiance
- 10/4/2023, Craig Johnston Multi Strand Simulations
- 8/24/2023, Sam Van Kooten Tracking bright points with shape-resolved observations Image: DKIST (pptx), (pdf)
- 7/26/2023, Jim Klimchuk The Thickness of Current Sheets and Implications for Coronal Heating
- 7/12/2023, James Leake The Onset of Magnetic Reconnection in Dynamically Evolving Current Sheets in the Solar Corona
- 5/31/2023, Vladimir Airapetian Signatures of Stellar Atmospheric Heating: From the Sun to Sun-like Stars
- 4/19/2023, Vadim Uritsky Reconstructing the cross-sectional geometry of a thin closed corona (pdf), (pptx)
- 4/5/2023, Jim Klimchuk The Unavoidable Thinning of Current Sheets
- 3/9/2023, Cosima Breu Broadening of coronal lines in a 3D MHD loop model
- 2/22/2023, Cecilia Mac Cormack Observation and modeling of solar coronal loops
- 1/25/2023, Biswajit Mondal Role of small-scale impulsive events in heating the X-ray bright points of the quiet Sun
- 11/30/2022, Jenny Marcela Rodriguez Gomez The COronal Density and Temperature (CODET) model, improvements and new perspectives
- 11/16/2022, Jeff Brosius Nonthermal Line Broadening and Velocities Observed by EUNIS- 2021 and EIS in the Core of AR 12824 (pdf), (pptx)
- 11/2/2022, Pankaj Kumar Plasmoids, flows, and jets associated with a failed filament eruption (pdf), (pptx)
- 10/19/2022, Shanwlee Sow Modal Simulations of spicules and constraints on their role in explaining hot coronal emission
- 10/5/2022, Vadim Uritsky On Loops and Veils
- 8/25/2022,Tom Howson Coronal Heating with Random Foot Point Driving: Understanding Time Scales
- 5/4/2022, Yihua Zheng Solar Irridiance: Measurement, Modeling and Connection to the Ionosphere -Thermosphere Dynamics
- 4/20/2022, Nicki Viall, Answering the Outstanding Questions of Solar Wind Physics using Ultraviolet Measurements of the Solar Corona
- 3/23/2022, James Leake, Onset of Reconnection in Dynamically Evolving Coronal Current Sheets
- 3/9/2022, Jim Klimchuk, Observational Signatures of Coronal Heating in MHD Models Without a Lower Atmosphere
- 2/25/2022, Anna Malanushenko,The Coronal Veil
- 2/9/2022, Terry Kucera, How do more realistic nanoflare distributions affect thermal nonequilibrium in model loops?
- 12/1/2021, Nicki Viall, Understanding Heating in Active Region Cores through Machine Learning
- 11/17/2021, Ineke De Moortel, Effectiveness of Heating in Driven Arcades with Different Driving Timescales
- 10/20/2021, Kalman Knizhnik, Reconnection Statistics in Nanoflares
- 10/6/2021, Lars Daldorff, Possible Consequences of the 3rd Dimension on Reconnection
Understanding Coronal Heating and the Solar Spectral Irradiance
- 9/22/2021, Jeff Brosius, Updates on EUNIS-2021
- 8/11/2021, Jim Klimchuk, Turbulence and the Formation of Coronal Current Sheets
- 7/14/2021, Doug Rabin, Coronal Microscale Observatory (CMO)
- 5/19/2021, Peter Young, Solar UV Bursts
- 3/24/2021, Vadim Uritsky, In search of new observational tests for small scale field aligned coronal structures,
- 3/16/2021, Jim Klimchuk, Kalman Knizhnik, Sam Schonfeld, Sherry Chhabra, ISFM Showcase, NASA HQ: Heating of the Magnetically Closed Corona
- 1/15/2021, Jim Klimchuk, Solar Physics Webinar of Global Reach, Heating of the Magnetically Closed Corona
- 12/2/2020, Sam Schonfeld, Considering the transition region when studying coronal heating
- 11/18/2020, Sherry Chhabra, Study of Type III Radio Bursts from Small-scale Reconnection Events
- 10/28/2020, Vadim Uritsky, Statistical modeling and analysis of multi-stranded coronal loops (part 2)
- 7/17/2020, Vadim Uritsky, HSD Director's Seminar, Can nanoflare heating define the coronal loop size?
- 7/17/2020, Terry Kucera, HSD Director's Seminar, Spectroscopic Constraints on the Cross-Sectional Asymmetry and Expansion of Active Region Loops
- 7/17/2020, Jim Klimchuk, HSD Director's Seminar, Cross Sections of Coronal Loops Flux Tubes 3/4/2020, Sam Schonfeld, Considering the transition region when studying coronal heating
- 3/4/2020, Sam Schonfeld, Considering the transition region when studying coronal heating
- 2/5/2020, Vadim Uritsky, Statistical modeling of multi-stranded coronal loops
- 1/29/2020, Jim Klimchuk, Spicules, Si IV Doppler Shifts, and Their Lack of Center-to-Limb Variation
- 10/9/2019, Craig Johnston, The effects of numerical resolution and background heating on thermal no-equilibrium in coronal loops (Johnston et al. 2019a,b)
- 7/24/2019, Emily Mason, Simulations of TNE in Raining Null-Point Topologies
- 4/17/2019, Nicki Viall, Nanoflare Timelage Observation and Modeling
- 4/17/2019, Jim Klimchuk, Modeling Solar Active Regions and their Emission
- 4/10/2019, Terry Kucera, Are Coronal Loops Really Cylindrical?: Spectroscopy Edition
- 3/27/2019, James Leake and Lars Daldorff, Investigating the Role of Magnetic Shear in the Onset of Magnetic Reconnection in the Corona
- 3/13/2019, Sam Schonfeld, Impacts of Intermediate Time Scale SSI Variability
- 3/6/2019, Joel Allred, Model of AR 11726 Heated by Nanoflares
- 12/4/2018, Marcelo López Fuentes, The Effect of Nanoflare Heating on Coronal Spectral Lines
- 11/7/2018, Jim Klimchuk, The detectability of individual nanoflares
- 10/3/2018, Vadim Uritsky, Scale-invariance and scale-dependence in impulsive coronal loop heating
- 9/12/2018, Emily Mason, Thermal Non-Equlibrium in Null-Point Topologies
- 5/19/2018, Jim Klimchuk, Thermal Non-equilibrium (TNE) In the Presence of Asymmetries
- 5/2/2018, James Leake, Investigating the Onset of Magnetic Reconnection in the Corona and Chromosphere
- 4/25/2018, Vadim Uritsky, Detecting current sheets in turbulent reconnecting plasmas
- 4/25/2018, Kalman Knizhnik, Collective Behavior in Drive Coronal Loops
- 4/25/2018, Lars Daldorff, Nanoflare on Kinetic Scale: Spectra for the smallest scales
- 4/25/2018, Jeff Brosius, Emission Lines Relevant to Nanoflare Heating Observed by EUV and UV Spectrometers
- 3/14/2018, Jim Klimchuk, Poynting Flux and Heating Rate
- 2/14/2018, Nicholeen Viall and Terry Kucera, Using SDO/AIA to Understand the Thermal Evolution of Solar Prominence Formation
Proposals
- Physical Models of Solar Active Regions and the Solar Spectral Irradiance Oct. 2024 - Sept. 2027.
Work-plan flow chart for the project. - Heating of the Magnetically Closed Corona Oct. 2021 - Sept. 2024
- Understanding Coronal Heating and the Solar Spectral Irradiance Oct. 2017 - Sept. 2020
Reports
Heating the Magnetically Closed CoronaHonors
NASA Robert H. Goddard Honor Award for Exceptional Achievement in Science to James Leak and Lars Daldorff for outstanding research leading to a breakthrough in understanding a key aspect of the fundamental physical process of magnetic reconnection.
Meetings
Meetings are usually alternating Wednesdays at 2:00 pm ET in GSFC building 33, room H118.
For more information about attending meetings contact PI Jim Klimchuk or deputy PI Terry Kucera.
Announcements
- June 2025: Work Package PI Jim Klimchuk was awarded the AAS/Solar Physics Division's George Ellery Hale Prize for his transformative contributions to understanding the Sun's hot atmosphere.
- September 2024: The team's proposal to the H-ISFM program Physical Models of Solar Active Regions and the Solar Spectral Irradiance was accepted. Work will start Oct. 1, 2024.
- September 2023: The work package team initiated the COSPAR International Space Weather Action Team (ISWAT) Origins of the Spectral Irradiance and its Intermediate Timescale Variability
- February 2022:
- Jim Klimchuk's Parker Lecture from the Dec. 2021 AGU meeting is now on line: Coronal Heating: A Coupled Multi-Scale Problem
- August 2021:
- NASA Robert H. Goddard Honor Award for Exceptional Achievement in Science to James Leak and Lars Daldorff for outstanding research leading to a breakthrough in understanding a key aspect of the fundamental physical process of magnetic reconnection.