2023 Boulder Solar Day Abstracts



Talks in chronological order: 

David Malaspina CU/LASP (1) APS Department, CU Boulder,
(2) LASP, CU Boulder,
(3) Princeton U.
(5) Catholic U.,
(6) SSL, Berkeley,
(7) UC Berkeley,
(8) U. Minnesota,
(9) Physics Department, CU Boulder,
(10) JHU/APL,
(11) LPC2E, CNRS, and U. Orleans, France
Discoveries in the Near-Sun Interplanetary Dust Environment made using Parker Solar Probe  Parker Solar Probe's unique orbit carries it closer to the Sun than any other human-made object.  This allows novel access to the near-Sun interplanetary dust environment.  This dense and dynamic region was previously unexplored by in-situ measurements.  Observations in this region are vital for understanding stellar processing of solar system dust. Determining solar dust processing physics such as sublimation, sputtering, solar wind mass loading, and collisional grinding lays the groundwork to interpret dust processing (and related planetary formation) in other stellar systems.
While Parker Solar Probe does not carry a dedicated dust detector, it 'sees' dust impacts via impact ionization.  When a micrometeoroid collides with the spacecraft, it produces a transient plasma cloud which perturbs the electric, and sometimes magnetic, environment near the spacecraft.  These perturbations are detected by the FIELDS instrument.
Analysis of these data has revealed (i) unexpected micrometeoroid populations, possibly formed by the interaction of asteroid and cometary debris trails with the densest parts of the interplanetary dust cloud, (ii) quantitative estimates of the mass flux ejected from the Sun by radiation pressure, (iii) unexpected short-time dust flux modulation, (iv) significantly more dust flux than leading models predicted, and (v) novel observations of spacecraft ablation and plasma environment modification due to micrometeoroid impacts. 
These studies demonstrate how electromagnetic detection of micrometeoroid impacts by spacecraft has opened new lines of research into the physics of solar (and by extension, stellar) processing of stellar system dust clouds.  
Kimberly Moreland CIRES/CU, NOAA/SWPC (1) CIRES, University of Colorado, Boulder
(2) NOAA Space Weather Prediction Center
(3) University of Máilaga, Spain
(4) NASA, Space Radiation Group
(5) NASA, Community Coordinated Modeling Center 
Validation of the UMASEP Solar Radiation Storm Model in the Space Weather Proving Ground The study of space weather is crucial for ensuring the functionality of satellites and other technologies in space. One aspect of space weather that can cause significant damage is radiation storms, which are bursts of high-energy particles that can disrupt electronics and harm astronauts. Accurate forecasting and modeling of such events is crucial for mitigating their impact. Working in a collaborative space weather proving ground with NASA CCMC, M2M, and SRAG we compare the UMASEP solar radiation storm model's predictions against NOAA SWPC's historical event forecasts to assess the models skill metrics and forecast lead times. The evaluation and validation of the UMASEP solar radiation storm model is a critical step in the readiness level process and future operational implementation of the model in the Space Weather Forecast Office.
Samaiyah Farid HAO/NCAR HAO(1-3) Exploring Dynamic Flows in the Middle Corona Transient coronal flows and jets exhibit indicators of magnetic reconnection including the apperance of blobs, bi-directional and downward plasma motions, and spectral line broadening. Recent observations with Parker Solar Probe show evidence of similar indicators of reconnection in the extended corona (3-5 Rsun). Many studies aim to trace flows in the extended corona, to their potential source regions in the lower corona, however much work is needed to understand the relationship between various coronal features, transient flows, and the formation of the solar wind. The Mauna Loa K-coronagraph (KCor) images the corona from 1-5 Rsun and is well suited to examine the formation and evolution of dynamic flows in the lower and middle corona. Here we discuss recent analysis a coronal jet and nearby outflows from the lower to outer corona using a combination of IRIS spectroscopic observations, SDO/AIA EUV images  and KCor polarized brightness images.
Kevin  France CU CU-Boulder Extreme Ultraviolet Observations of Nearby Stars:  Probing Stellar Physics and Estimating Atmospheric Escape from Potentially Habitable Exoplanets Ultraviolet spectroscopy is a primary tool for probing the hot atmospheres of planet-hosting stars (spectral types F – M).  The 10 – 320 nm ultraviolet bandpass contains key diagnostics of the full temperature range from the chromosphere to the corona, is the most sensitive bandpass for stellar flares studies, and can provide direct constraints on stellar coronal mass ejections.  After their emission from the star, high-energy photons and particles regulate the atmospheric temperature structure and photochemistry on orbiting planets, influencing the long-term stability of planetary atmospheres and driving atmospheric photochemistry.   As the field of exoplanet characterization has grown over the past decade, so have large ultraviolet survey programs targeting cool stars.
I will give an overview of recent key results from ultraviolet studies of cool stars (focusing on the "extreme ultraviolet" bandpass, 10 – 91 nm), with an emphasis on implications for atmospheric photochemistry and escape.  I will conclude by presenting the landscape for stellar and exoplanetary investigations utilizing ultraviolet observations over the next two decades.  Missions of all sizes have important roles to play in this area: I will highlight planned or proposed missions ranging from smallsat through medium-class missions to flagships.
Lisa Winter NSF NSF NSF Solar Support NSF supports vibrant research and educational projects in the Boulder area. Some of this work is highlighted to showcase and connect solar scientists in the local area.
Steven Tomczyk HAO/NCAR High Altitude Observatory/ National Center for Atmospheric Research Initial Observations with the Upgraded Coronal Multi-channel Polarimeter (UCoMP) The Upgraded Coronal Multi-channel Polarimeter (UCoMP) is a 20 cm coronagraph that combines a full Stokes polarimeter with a narrow-band tunable Lyot filter. It is capable of performing imaging spectropolarimetry across a wide range of emission lines in the visible and near-IR regions of the coronal spectrum. The UCoMP is an upgrade of the CoMP instrument with a broader wavelength range, larger field-of-view and higher spatial resolution than its predecessor. The UCoMP demonstrates the technology of a large aperture (50 mm) tunable birefringent filter based on Lithium Niobate crystals that is pathfinder instrument for the COSMO project. The instrument was deployed to the Mauna Loa Solar Observatory and started taking data May 26, 2021, followed by a period of instrument commissioning. This presentation will describe the UCoMP instrument, illustrate its operation with samples of the data it produces, and highlight initial results from the instrument.
Savannah  Perez-Piel UC Berkeley Space Sciences Laboratory  (1) Space Sciences Laboratory - University of California, Berkeley,         
(2) NorthWest Research Associates​
Temporal Defocusing: A New Depth Diagnostic of Sources of Transient Seismic Emission from Solar Flares Some solar flares drive tremors, known as 'sunquakes,' across the solar surface. These sunquakes propagate outward from the flare site over the hour, succeeding the impulsive phase. These tremors are a manifestation of acoustic transients that have traveled deep into the solar interior from the flare's location and have thenceforth been refracted back upward to the Sun's surface tens of thousands of kilometers outside of the flaring region.
Our study examined two distinct sunquakes. One exhibited signs of a submerged acoustic source, while the other showed evidence of a superficial source. We applied a novel depth diagnostic dependent on the temporal defocusing of the seismic signature and then contrasted the familiar spatial defocusing on which computational helioseismic holography has capitalized from its early advent. With the utilization of both temporal and spatial defocusing methodologies, we not only affirm the existence of a submerged source in the 10-mHz spectrum and in the flare of 2014-02-07 at 10:28 UTC, but we also detected indications of a secondary submerged acoustic such source linked to the flare of 2011-07-30, at 02:09 UTC. We emphasize the pivotal role of the high-frequency components of these transients in the spatial resolution that shows the fine structure of these sources, including their depths. In addition, we outline plans for control work needed to discern genuine sunquake-driven signatures from possible artifacts of our diagnostics.
Karin Dissauer NorthWest Research Associates (1) NorthWest Research Associates, Boulder, CO, USA;
(2) Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
Unveiling the nexus: Exploring the connection between precursor activity and solar energetic events We investigate the uniqueness and physical role of small-scale phenomena that precede solar flares and coronal mass ejections (CMEs). This includes transient brightenings (TBs) in extreme-ultraviolet and soft X-rays resulting from plasma heating and particle acceleration, along with flows of hot plasma along coronal loops and pre-event coronal dimmings (PCDs) hypothesized to indicate early filament activation or the rise of overlying fields that enable subsequent coronal mass ejections (CMEs).

The precise roles of these signatures, mostly reported in single-event case studies, in the initiation and early evolution of solar energetic events is still unclear. Whether these phenomena predominantly occur during an active region's pre-event phase or are just randomly occurring in the solar atmosphere is also still unclear.

This contribution systematically explores the uniqueness and causal relationship between so-called "precursor activity" and solar flares/CMEs using a significant statistical dataset. The temporal behaviors of TBs and PCDs, their photospheric magnetic context, coronal dynamics, and temperature/density characteristics before events are analyzed and compared against similar activity during quiet epochs of the same active regions (testing for uniqueness). Additionally, we also check if pre-event activity is linked to reconnection-prone locations (open field regions, magnetic null points etc.) by constructing the topological skeleton of the host active regions using a Potential Field Source Surface model (testing for causality).

Archived data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO), specifically EUV time-series images and vector magnetograms are used to present preliminary results.

We acknowledge funding from NASA award No. 80NSSC21K0738 and NSF AGS-ST Grant 2154653.

Donald Schmit NOAA NOAA Getting Ready for NOAA's Fleet of Upcoming Coronagraphs NOAA has been reliant on NASA's LASCO instrument to identify and track coronal mass ejections for decades. This year we will see the first in a series of NOAA commissioned coronagraphs, the Compact Coronagraph (CCOR-1), launch aboard the GOES-U spacecraft. This presentation will describe the specifications of these coronagraphs and their data products, the Spaceweather Follow On (SWFO) platform, and how the data will be used in forecasting applications.
Yuta Notsu CU/LASP/NSO (1) CU Boulder/ LASP/NSO       
(2) NAOJ
Recent observational attempts to observe stellar CMEs Solar flares are often accompanied by filament/prominence eruptions, sometimes leading to coronal mass ejections (CMEs). By analogy, we expect that stellar flares are also associated with stellar CMEs whose properties are essential to know the impact on exoplanet habitability. Probable detections of stellar CMEs are still rare, but in very recent years, there have been several reports that stellar (super-)flares on G,K,M dwarfs show blue-shifted optical/UV/X-ray emissions lines, XUV/FUV dimming, and radio bursts. Some of them are interpreted as indirect evidence of stellar prominence eruptions/CMEs on cool stars. In particular, we have worked on the observation campaigns of young G-dwarfs (solar-type stars) and M-dwarfs and have reported evidence of stellar filament/prominence eruptions, probably leading to a CME, as a blue-shifted absorption of chromospheric lines associated with a superflare. Notably, the erupted masses for these stellar flares are larger than those of the largest solar CMEs, indicating severe influence on exoplanet environments. These mass is roughly consistent with the scaling relation expected from solar CMEs. However, the ratio of the kinetic energy of stellar CMEs to flare energy is significantly smaller than expected from the solar scaling relation and this discrepancy is still in debate. In this talk, we will introduce recent updates of stellar CME studies especially focusing on our recent reports of stellar filament/prominence eruptions, and discuss the future prospects including the importance of more collaborations with solar-based observation/modeling studies.
Lisa  Upton Southwest Research Institute (1) Southwest Research Institute, Department of Solar and Heliospheric Physics, Boulder, USA;
(2) Stanford University, Hansen Experimental Physics Lab, Stanford, USA;
Polar field precursors, geomagnetic precursors, and curve fitting: The outlook for Solar Cycle 25 The strength of the polar fields and the geomagnetic precursors (e.g., the aa index) at solar minimum are established predictors of the amplitude of the solar cycle. Surface Flux Transport (SFT) models describe the process by which magnetic flux from the active regions is transported to the poles and can be used to estimate the polar field strength well before minimum. The Advective Flux Transport (AFT) model, a state-of-the-art SFT model, was designed with the intent of creating the most realistic SFT model possible. AFT has proven successful at predicting active region evolution and decay as well as the evolution of the Sun's polar fields. In 2016 and 2018, AFT was used to create forecasts of the Sun's polar field and predict the strength of Solar Cycle 25 - predicting a weak cycle. During solar minimum (December 2019) the polar field and geomagnetic precursors both indicated that Cycle 25 would indeed be a small cycle, but the prediction from the geomagnetic precursor was about 20-30% higher than the prediction from the polar fields. Now that we are a well into the cycle, we can use curve fitting to provide an additional prediction for the amplitude of Solar Cycle 25. We present an update on the current state of the solar cycle and show how the latest observation compare with the AFT predictions. We show a comparison of the prediction from the geomagnetic and polar field precursor methods. Finally, we provide an update on the outlook for Solar Cycle 25.
Dainiela Lacatus HAO/NCAR HAO/NCAR Evolution of Spectroscopic Characteristics of Solar Filaments We present a detailed investigation of characteristics of solar filaments derived from the chromospheric emission captured by the Mg II resonance lines from the Interface Region Imaging Spectrograph (IRIS) and their relation to the surrounding solar atmosphere. Despite being long-lived structures, filaments show a dynamic evolution of their morphology and properties on both spatial and temporal scales. Given the Mg II lines formation spans the whole chromosphere, these lines can capture changes within the larger structure, corresponding to individually evolving strands. Additional derived characteristics provide information on the emitting region as well as reveal flows and hints of potential destabilization. We present our exploration for finding the best set of parameters for filament identification and pinpointing the loss of confinement.
Tom Schad National Solar Observatory National Solar Observatory The Inouye Solar Telescope:  Early Science Highlights from Cycle 1 and 2 The National Science Foundation's Daniel K Inouye Solar Telescope began its science operations commissioning phase in December 2021, thereby becoming the world's largest solar telescope in operation.  This inaugural first cycle extended through December 2022, supporting PI-led experiments utilizing the VBI, ViSP, and CryoNIRSP instruments.  This was the first time the full lifecycle of PI-defined service-mode observations was fully exercised.  In addition, the first project-led coordinated observations generated open community data sets during Encounter #12 of Parker Solar Probe and Remote Science Window #5 of Solar Orbiter.  This talk highlights these early data and discusses early science results from the science verification phase and Cycle 1.  We also will have an early look at Cycle 2 datasets which have opened up many more instrument capabilities to the community. 
David Kuridze National Solar Observatory National Solar Observatory Fine-scale structure of the plage chromosphere with DKIST The strongly coupled hydrodynamic, magnetic and radiation properties of the plasma in the solar chromosphere makes it a region of the Sun's atmosphere that is poorly understood.  We use data obtained with the high-resolution Visible Broadband Imager (VBI) equipped  with the H-beta filter and Visible spectropolarimeter (ViSP) on The Daniel K. Inouye Solar Telescope (DKIST), to investigate fine-scale structure of a plage chromosphere.  To aid the interpretation of the DKIST filtergraph, we also analyzed H-beta scans obtained with the CHROMospheric Imaging Spectrometer (CHROMIS) on the Swedish Solar Telescope. The analysis of spectral properties, such as enhanced line widths and line depths explains the high contrast of the fibrils relative to the background atmosphere confirming that H-beta is an excellent diagnostic for the enigmatic fine-scale structure of the chromosphere. Correlation between H-beta line depth and width indicates that opacity broadening created by overdense fibrilscan be a main reason of the spectral line broadening observed frequently in chromospheric fine-scale structures. We also found hot transition region signatures for chromospheric H-beta fibrils indicating the multithermal nature of chromospheric canopy dominated with local heating and cooling processes. Analyses of polarization data show that the morphological characteristics of plage fibrils are defined by the topology of magnetic field in the lower solar atmosphere.
Delores Knipp CU (1) Smead Aerospace Engineering Sciences Department, CU Boulder,           
(2) Associate Scientist, CU Space Weather Technology Research and Education Center,
(3) Senior Research Associate, NCAR High Altitude Observatory
When the Sun Goes Rogue The 1859 Carrington-Hodgson solar eruption event is the benchmark against which most space weather events are compared. Might there be others in the same class? I will recount, in abridged form, several such rogue events documented in the course of written history. Some of these events mesmerized/terrified populations who observed great red aurora. Some of these events likely changed the course of history. One of these events brought us to the brink of World War III. Another event was so inconceivably fast in its Sun-Earth transit that it took years to stitch together the facts into a comprehensive analysis. These great events are rarely singular, rather they occur in series. The repetitive or serial nature of these events has significant implications for our technology dependent society when (not if) the Sun goes rogue.


Andrei Afanasev LASP (1) LASP, (2) NSO,    (3) HAO, (4) CSIRO Magnetic evolution of an eruptive solar active region simulated with the hybrid data-driven magnetofrictional and MHD approach We present the hybrid numerical simulations of active region NOAA 11158 that produced an X-class flare and coronal mass ejection on Feb 15, 2011. We first use the data-driven magnetofrictional method within the Coronal Global Evolutionary Model (CGEM) framework to simulate the slow pre-eruption evolution of the active region from the magnetic flux emergence on the photosphere until the formation of twisted and sheared magnetic structures at coronal heights before the eruption. We drive the bottom domain boundary using the electric fields derived from HMI data with the PDFISS method. Then we compute the subsequent dynamic eruption evolution of the coronal magnetic configuration by using the data-constrained MHD Magnetic Flux Eruption code. We present details of the hybrid simulations and discuss the results, focusing on understanding the structure of sheared and twisted magnetic fields in the active region and the eruption mechanism. We analyze the magnetic configuration parameters against the development of the torus and kink instabilities and compare the simulated magnetic fields with EUV observations.
Joan Burkepile HAO/NCAR (1) High Altitude Observatory / NCAR,
(2) NASA Goddard Space Flight Ctr,       
(3) NASA Community Coordinated Modeling Center (CCMC),       
(4) NASA Space Radiation Analysis Group (SRAG)
Near-real-time Coronal Mass Ejection Alerts as part of an Early Warning Forecasting System for Solar Energetic Particle (SEP) events The NCAR Mauna Loa Solar Observatory (MLSO) COSMO K-Coronagraph (K-Cor) issues near-real time coronal mass ejection (CME) alerts to the community and to NASA's Community Coordinated Modeling Center Solar Energetic Particle (SEP) scoreboard for use by the NASA Space Radiation Analysis Group in support of the Artemis mission. The COSMO K-Cor observes the low and middle solar corona in polarized broadband white light at very high time cadence and with very low data latency, making it ideally suited to study the onset and dynamics of coronal mass ejections (CMEs). The K-Cor automated data processing system includes CME detection code that can provide the first warning of an in-progress CME. This information can lead to improvements in SEP forecasts (see St. Cyr et al. 2017). We show that most of the K-Cor alerts were issued before the CME entered the LASCO field-of-view. When LASCO data latency is included, the K-Cor alerts provide, on average, tens of minutes to an hour warning of an in-progress CME before it can be seen in space-based coronagraph images. We discuss the CME detection system and present statistics on performance. We present ongoing work to improve performance and highlight the benefit of ground-based coronagraph network (ngGONG mission).
Shivank Chadda CU University of Colorado Boulder,  Laboratory for Atmospheric and Space Physics, ETH Zürich Solar Rotation modulation of Interstellar Dust inside the solar system Interstellar dust (ISD) is dispersed throughout our solar system. Until recently, understanding the transport of interstellar dust within the heliosphere has been limited by a scarcity of long-duration in-situ dust measurements.
Using over a solar cycle of data from the STEREO spacecraft at 1 AU, we found that the Sun's 26-day rotation and 11-year solar cycle modulate solar wind properties, thereby affecting the ISD flux that reaches 1AU.
Further, a 26-day modulation of dust impacts observed by the Wind spacecraft (at the L1 Lagrange point) is similar to that observed on STEREO-A and STEREO-B, demonstrating that the observed modulation is physical. We used the STEREO data to validate a simulation-based prediction that the ISD flux at 1 AU is modulated by the 11-year periodic flips of the Sun's magnetic field.
We have developed a two-dimensional test particle simulation to explore ISD interaction with fast solar wind streams and magnetic sector boundary changes. We have observed that the structure of the heliospheric current sheet (HCS) causes dust particles to undergo periodic deflections about the equatorial plane. Further, the detectability of ISD near Earth depends strongly on the initial conditions that the ISD encounters at the edge of the heliosphere.
We conducted an extensive parametric study within the simulation to investigate the physical mechanism behind the observed clustering of dust detections. This phenomenon is attributed primarily to the structure of the HCS near the ecliptic plane and to the latitude at which the ISD first encounters the heliosphere.  Our research provides one possible mechanism for ISD clustering near Earth.
Marcel  Corchado-Albelo CU (1) University of Colorado Boulder, Department of Astrophysical and Planetary Sciences/National Solar Observatory/Laboratory for Atmospheric and Plasma Physics.        (2) University of California Berkeley/Space Sciences Laboratory Flare Magnetic Reconnection Dynamics Inferred from Flare Ribbons: Oscillations in the Reconnection Flux Rates and HXR Emission. Magnetic reconnection is understood to be the main physical process that transforms magnetic energy into heat, motion and particle acceleration in flares. Yet, observational constraints on magnetic and plasma properties of the reconnection region, and the dynamics that occur there are limited because of the high cadence and spatial resolution needed to capture these during a flare. Hard X-Ray (HXR) emission during flares allow us to indirectly understand properties of the magnetic reconnection process related to particle acceleration. To estimate the magnetic reconnection flux and its rate of change with time we study the evolution and morphology of post-reconnected field-line footpoints, or flare ribbons. Using 1600 Ã… Atmospheric Imaging Assembly (AIA) and the Helioseismic Magnetic Imager (HMI) vector photospheric magnetic field we estimate the reconnection budget and reconnection rate, which allows us to probe dynamics of the current sheet above. We compare high resolution data from the Slit-Jaw Imager (SJI) onboard the Interface Region Imaging Spectrograph (IRIS) to study the evolution of fine-structures in the flare ribbon as they spread away from the polarity inversion line. We study the temporal relationship between the evolution of these fine structures and the quasi-periodic pulsations (QPP's) signatures in the derived reconnection rates. Additionally, we use the RibbonDB database to perform statistical analysis of  73 C- to X-class flares and identify the relationship between the QPP's in the reconnection rate and HXR emission properties using multiple spectral (Fourier and Wavelet) analysis.  We find that the oscillations' periods range from one to four minutes and are nearly cotemporal. We discuss how current sheet plasmoids could explain these observations, and how future studies could explore the diagnostic potential of these QPP observations.
James Crowley CU/NSO (1, 2) National Solar Observatory,
(1) CU Boulder,
(2) CIRES,
(3) Predictive Science Inc.
Magnetic Insights from Inversions of Hinode SP  Over the last few years, a new wave of high-resolution solar telescopes and in-situ observations have revealed complicated and dynamic interactions between the Sun's surface, magnetic field, and the inner heliosphere. To probe these connections, we use a state of the art global MHD simulation with a lower boundary condition supplied by vector magnetograms from HMI and Hinode/SP inversions. In this poster, I will explain our process in creating, disambiguating, and validating the Hinode/SP magnetograms, as well as interesting findings about the retrieved magnetic properties.
João Manuel da Silva Santos NSO NSO, CU-Boulder Magnetic fields in solar plage regions: insights from DKIST/ViSP spectropolarimetry Previous studies have provided insights into the properties of magnetic fields in solar plage regions, but accurately measuring chromospheric magnetic fields has remained a challenging yet crucial task for understanding chromospheric heating and dynamics. In this study, we utilized high-sensitivity (S/N~8×10 -4) spectropolarimetric data obtained by VBI the four-meter Daniel K. Inouye Solar Telescope (DKIST) to investigate the dynamic environment and distribution of magnetic fields in an extended, decaying plage region. We find strong polarization signals in plages and neighboring fibrils, with the linear polarization signals clearly distinguishing between plage patches and the chromospheric fibril canopy. Inversions show fibril-like structures in the magnetic field, with typical field strength values ranging from approximately 200 G to 300 G. Moreover, we observe large Doppler shifts (up to 15 km/s) and complex profiles at the plage peripheries indicating strong flows and velocity gradients. These results help us understand the magnetic field properties and dynamic processes within plages, underscoring the need for further research to explore magnetic field expansion with height and how that affects the heating rates.
Jonathan Darnel CU University of Colorado Estimating EUV Instrument Degradation Using DEM Analysis NOAA's Solar UltraViolet Imager (SUVI) is a series of nearly-identical solar EUV imagers hosted aboard the GOES 16-18 and upcoming GOES-U satellites. Degradation of solar EUV instruments over time is a expected and many strategies have been developed to track and quantify that degradation. The overlapping periods of operation of the SUVI instruments provide a unique opportunity to study the relative degradation trends and their impacts on the data and subsequent analysis thereof. Herein, we will present the impacts to the results of DEM analysis using SUVI data.   
Michael Galloy HAO/NCAR (1) HAO/NCAR,            
(2) University of Michigan,                   
(3) Ball Aerospace,   
(4) Peking University
  NCAR/HAO has successfully deployed the new Upgraded Coronal Multi-channel Polarimeter (UCoMP; Landi, Habbal and Tomczyk, 2016). It is a 20-cm aperture Lyot coronagraph with a Stokes polarimeter and a narrow-band electro-optically tuned birefringent filter that images the intensity, full Stokes polarization, and Doppler shift across coronal emission lines in the visible and near-IR. It has a broader range (530 - 1083 nm) than CoMP (1074 - 1083 nm), observing 9 emission lines (vs 3 for CoMP). It has a dramatically faster collection of the full Stokes polarization than CoMP, providing higher quality polarimetry and Doppler measurements. UCoMP also has a larger field-of-view (+/- 2 Rsun) [CoMP +/- 1.3 Rsun], and 6 arcsec spatial resolution (CoMP 9 arcsec).
UCoMP provides powerful diagnostic measurements of the coronal magnetic field and plasma properties. The expanded capabilities of UCoMP provide observations over a wide range of coronal temperatures. The larger field-of-view allows it to explore the magnetic and thermal properties of dynamic structures, such as Coronal Mass Ejection (CMEs), and ambient coronal structures, such as coronal cavities, pseudo-streamers, and the polar corona out to greater heights.
We provide examples and descriptions of the variety of UCoMP data products and information about the calibration and processing steps used to produce Level-1 and Level-2 science data. Information on data access and downloading the User Guide is provided. We seek community input for designing observing campaigns that optimize the collection of observations needed to maximize scientific return.
Sarah Gibson HAO/NCAR (1) HAO/NCAR;       
(2) U. of Michigan;     
(3) U. of Hawaii;       
(4) Harvard Smithsonian CfA;          (5) George Mason U.; (6) National Solar Observatory
CORONAL SOLAR MAGNETISM OBSERVATORY COSMO is a proposed synoptic facility designed to measure magnetic fields and plasma properties in the large-scale solar atmosphere. Measurements of coronal and chromospheric magnetic fields are arguably the most important observables required for advancing our understanding of the processes responsible for coronal heating, coronal dynamics and the generation of space weather that affects communications, GPS systems, space flight, and power transmission.
COSMO will provide a unique combination of magnetic field, density, temperature, and velocity observations in the corona and chromosphere, transforming our understanding of fundamental physical processes in the solar atmosphere and revealing their role in the origins of solar variability and space weather.
Holly Gilbert HAO/NCAR NCAR/HAO + others The Chromospheric Magnetism Explorer (CMEx) CMEx is a mission concept submitted to NASA's Heliophysics SMEX program that, if selected, will fly in 2028. CMEx uses ultraviolet spectropolarimetry to diagnose magnetism from the solar photosphere to the transition region, leveraging the heritage of both IRIS and Hinode. CMEx explores how the magnetic field evolves from the β >> 1 photosphere to the β << 1 corona to form twisted non-potential flux ropes in the corona that are the energy storage devices for magnetic eruptions. This key β transition happens in the chromosphere where only UV spectropolarimetry can give us access to the highly complex dynamics where plasma properties change rapidly. Recent advances in the understanding of the polarization of UV chromospheric lines, which are not observable from the ground, have primed a space-based mission like CMEx for success.
Stuart Gilchrist Planetary Science Institute Planetary Science Institute Bayesian validation of coronal magnetic field extrapolations Methods for "extrapolating" the coronal magnetic field from photospheric vector magnetogram data are becoming increasingly popular as a tool to study coronal phenomena. However, extrapolations have always had a "validation problem": the coronal magnetic field is not well measured,  so validation of extrapolations via direct comparison with the coronal field is not possible. How then do we know when an extrapolated  magnetic field should be believed?  Here we address the validation problem using a Bayesian hypothesis-testing framework. Bayesian methods are useful in contexts where there is  too little information for a direct comparison, and we must instead rely on more uncertain criteria.  This material is based upon work supported by the National Science Foundation under Grant No. 1841962. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. 
Bradley Hindman CU (1) University of Colorado Boulder,     
(2) Stanford University,
(3) Universistat Politècnica de Catalunya,                 
(4) Southwest Research Institute,   
(5) University of California, Santa Cruz
Meridional circulation through the lens of helioseismology We apply the ray-theory averaging kernels that are used in time-distance helioseismology to the meridional flows achieved in a sequence of numerical simulations. The numerical simulations cover the lower 5 density scale heights of the Sun's convection zone (reaching up to 0.98 R) and span a range of Rossby numbers between 0.25 and 2.0.  Some have a solar-like differential rotation and others are anti-solar. All of the models with a solar-like differential rotation possess multiple meridional circulation cells in each hemisphere, particularly at low-latitudes. By convolving the averaging kernels with the simulated flow fields, we generate a reconstructed flow field that estimates what a seismic analysis would measure.  We find that all of the flow fields within the upper half of the convection zone are well-reproduced, even those with near-surface reversals in flow direction. On the other hand, the lower half of the convection zone can suffer significant contamination from near surface flows due to side lobes in the averaging kernels. Only in the models with the fastest flows at depth do deep cells survive the convolution process.
Marcus Hughes SwRI (1) Southwest Research Institute Using Foundation Neural Networks to Improve Solar Image Segmentation Identifying solar phenomena such as flares and coronal holes in real-time is invaluable for space weather forecasting as it allows early detection of the drivers of geoeffective events. NOAA currently produces a product called thematic maps that segments extreme ultraviolet (EUV) images utilizing a pixel-based machine learning technique. This product is meant to streamline the labeling of solar structures enabling both human forecasts and other automatic applications (such as flare identification reports). Currently, thematic maps suffer from a variety of complications that limit their usability: degradation, limited testing, lack of textural information, lack of context. To improve upon these limitations, we train an ensemble of fine-tuned Segment Anything Models (SAM). SAM is a computer vision foundation model, i.e. a model trained on a broad task that can be fine-tuned for other tasks, created by Meta AI in 2023. By using an ensemble, we measure the model's confidence in labeling. Finally, we characterize and compare the performance of both the current thematic map and our new SAM-based version.
Megan Kenny CU Boulder University of Colorado Boulder A Trip to the Sun in Poems: A Book of Heliophysics Poetry for Kids and Beyond This short collection of rhyming poems takes the reader/listener on a journey to the Sun to learn about how our solar system formed, how the Sun came to be, how the Sun produces energy, how our star's energy sustains life here on Earth. The intention of this project was to formulate an accessible and light-hearted, yet scientifically rich resource for early students of the Sun. I plan to publish this book so that the resource becomes more widely usable. 
Don Kolinski HAO/NCAR HAO, SwRI, many others for whole PUNCH team PUNCH (Polarimeter to UNify the Corona and Heliosphere) PUNCH is a NASA Small Explorer mission to better understand how the mass and energy of the Sun's corona become the solar wind that fills the solar system. The flight segment consists of a constellation of four small satellites in Sun-synchronous, low Earth orbit that together will produce deep-field, continuous, 3D images of the solar corona as it makes a transition to the young solar wind from the outermost solar atmosphere to the inner heliosphere.
PUNCH's science goal is to comprehend cross-scale physical processes of heliophysics, from micro scale turbulence to the evolution of global scale structures. There are six science objectives that span the quiescent and dynamic young solar wind, which will be achieved by activities of six working groups. PUNCH is sponsoring a series of open workshops with the heliophysics community to develop tools in anticipation of the data and to foster a broad and inclusive community of PUNCH users. Workshops are announced in field newsletters and on the PUNCH mission website.
An undergraduate student collaboration to search for X-ray signatures of coronal heating mechanisms includes development of another instrument, the Student Thermal Energetic Activity Module (STEAM). Moreover, PUNCH engages interested heliophysicists in a mission-embedded outreach program with an Ancient & Modern Sun Watching theme that is collaborating with under-served and underrepresented populations and connecting to the broader public in the US Southwest and beyond. PUNCH is scheduled to launch in April of 2025.
Greg Kopp LASP (1) CU/LASP,             
(2) SSRC,                   
(3) NRL
Reconstructions of Historical Solar Activity To extend the space-era measurement records of total solar irradiance (TSI) back in time, as needed for understanding natural influences on Earth-climate variability, a modeling-focused effort has been completed to create an historical TSI reconstruction using new Advective Flux Transport (AFT) simulations of solar activity over the last 300 years guided by the updated Sunspot Index and Long-term Solar Observations (SILSO) sunspot-number records.
Greg Kopp LASP (1) LASP,                   
Tying It All Together: The Sun as an On-Orbit Reference The Sun is the most accurately known and most stable light source capable of providing a reference for spaceborne instruments measuring solar-reflected scenes from the Earth over Earth-climate timescales. Using the known, SI-traceable spectral solar irradiance as a calibration reference, the CLARREO Pathfinder's HyperSpectral Instrument for Climate Science (HySICS), an imaging spectrometer to be launched in 2024, provides relative measurements of Earth-scene reflectances with < 0.3 % (k=1) uncertainties across most of the 350- to 2300-nm range. The ARCSTONE, a 6U CubeSat spectrometer with an anticipated mid-2024 launch, uses a similar on-orbit solar cross-calibration approach to acquire spectral lunar-irradiance measurements with uncertainties < 0.5 % (k=1) across the same wavelength range, enabling other Earth-viewing instruments able to view the Moon to improve their on-orbit radiometric calibrations. The Sun thus provides improvements in SI traceability for space-based Earth-climate studies in the reflected-solar spectral region.
Lydia Korre CU CU/SwRI Transport by meridional flows in the solar interior Transport by meridional flows may have significant implications in the dynamical interaction between convective and radiative regions in solar-type stars, because it can contribute to the mixing of chemical species and the transport of angular momentum and magnetic fields. To examine these dynamics, we have run a series of three-dimensional global numerical simulations in a rotating spherical shell that consists of an outer convective region overlying a stably stratified zone. We vary the number of density scale heights in the convection zone, along with the degree of convective driving and the rotation rate, and systematically study how these effects impact the dynamical balances and angular momentum transport established throughout the convection zone and the radiative interior. When operating in the solar-like regime, where the Eddington-Sweet timescale $t_{ES}$ is shorter than the viscous timescale $t_{\nu}$, as measured by the parameter $\sigma = (t_{ES}/t_{\nu})^{0.5}, we find that the mean flows can travel large distances beyond the convective boundary into the radiative region. We provide scaling laws of the penetration depth of these mean flows below the base of the convection zone with respect to $\sigma$.
Ultimately, our findings may lead to a better understanding of the role the meridional flows play in different dynamical processes occurring in the solar interior.
Larisza Krista CU/CIRES, NOAA/NCEI CU/CIRES, NOAA/NCEI A DEFT approach to finding pre-flare events in a forest of EUV signatures It is widely accepted that solar flares are powered by free magnetic energy built up in the corona. However, this energy alone might not be sufficient to initiate an eruption. Flare initiation and onset mechanisms are one of the most debated subjects in solar physics. A large-scale statistical study is crucial to investigate the evolution of flare precursors and their link to flare initiation.

The Detection and EUV Flare Tracking (DEFT) tool can identify flare precursors in high temporal and spatial resolution extreme-ultraviolet (EUV) solar observations (e.g. SDO/AIA and GOES/SUVI). DEFT is a fast and robust tool that can determine and track the location, magnitude and change in EUV signatures from one observation to the next. Using a differentiation technique it identifies potential EUV flare precursors amongst a vast number and variety of EUV signatures. In a study of over 1500 flares we found that EUV signatures are consistently observable before B, C, M and X class flares. We hypothesize that the EUV flare precursors we observe are small-scale ongoing reconnection events produced by the increasing magnetic complexity in regions that later produce flares. 

Bhishek Manek LASP/CU University of Colorado Boulder Deep convection driven from the solar surface Solar convection plays an important role in transporting energy, chemical elements, and magnetic fields, in maintaining differential rotation, and in the overall operation of the solar dynamo. Helioseismic techniques like ring-diagram and time-distance used to infer the subsurface structure and amplitudes of deep convection give conflicting results leading to the convective conundrum. Hence, understanding the onset and driving mechanisms of deep solar convection is of crucial importance. In this work, we present 3D Cartesian simulations that explore the onset and setup of a deep solar convection zone self-consistently atop a radiative interior. We treat the radiative transfer using a Kramers-like opacity, along with a highly unstable near-surface layer, allowing for a self-consistent coupling between the solar convection zone and the radiative interior. We investigate the depth of the formed convection zone, the extent of overshooting convective motions, and the convective spectrum at various depths for a range of non-dimensional parameters.
Vanessa Maria Mercea Technical University of Cluj-Napoca, Romania (1) Technical University of Cluj-Napoca, Romania;                   
(2) High Altitude Observatory, Boulder, Colorado,                 
(3) High Altitude Observatory, Boulder, Colorado,                 
(4) Technical University of Cluj-Napoca, Romania;                   
(5) Astronomical Institute of the Romanian Academy
A Machine Learning Enhanced Approach for Automated Sunquake Detection in Acoustic Emission Maps Sunquakes are seismic emissions visible on the solar surface, associated with some solar flares. Although discovered in 1998, they have only recently become a more commonly detected phenomenon. Despite the availability of several manual detection guidelines, to our knowledge, the astrophysical data produced for sunquakes is new to the field of machine learning. Detecting sunquakes is a daunting task for human operators, and this work aims to ease and, if possible, to improve their detection. Thus, we introduce a dataset constructed from acoustic egression-power maps of solar active regions obtained for Solar Cycles 23 and 24 using the holography method. We then present a pedagogical approach to the application of machine-learning representation methods for sunquake detection using autoencoders, contrastive learning, object detection and recurrent techniques, which we enhance by introducing several custom, domain-specific data augmentation transformations. We address the main challenges of the automated sunquake-detection task, namely the very high noise patterns in and outside the active region shadow and the extreme class imbalance given by the limited number of frames that present sunquake signatures. With our trained models, we find temporal and spatial locations of peculiar acoustic emission and qualitatively associate them to eruptive and high energy emission. While noting that these models are still in a prototype stage, and there is much room for improvement in metrics and bias levels, we hypothesize that their agreement on example use cases has the potential to enable detection of weak solar acoustic manifestations.
Momchil Molnar HAO/NCAR (1) HAO, NCAR Explaining the vanishing high-frequency phase delays of chromospheric diagnostics  Phase delays between spectral line features formed at different heights in the solar atmosphere are a diagnostic of vertically propagating disturbances. There has been a long standing question why high-frequency (above about 5 mHz) phase delays between Doppler velocity diagnostics formed in the photosphere and chromosphere of the quiet sun go to zero, whereas lower frequency signals above the acoustic cutoff exhibit signatures of propagating acoustic waves. Possible explanation is that the phase speeds of these types of waves are significantly higher than their lower frequency counterparts, or that a high-frequency wave damping mechanism is in play. We address this question by examining the propagation of waves in MURaM radiative magnetohydrodynamic (rMHD) models of the solar atmosphere. In particular, we extend the previous work by Fleck et al. (2021) by using rMHD models extending into the chromosphere and the corona. We synthesize observable diagnostics (Fe I photospheric lines, Ca II IR triplet, Na I D lines, and the Mg II h&k lines) with the RH15D code from these models. Based on the synthetic observables we explore the possible explanations of the the vanishing high-frequency phase delay conundrum. We also attempt to address this question by using non-LTE inversions to look for signs of vertically propagating waves. We show the limitations of spectral inversions for wave studies in the chromosphere.
James Mothersbaugh III CU (1) University of Colorado Boulder CIRES;
(3) University of Colorado Boulder LASP;
50 Years of GOES XRS Science-Quality Data The X-Ray Sensor (XRS) instrument has flown on every Geostationary Operational Environmental Satellite (GOES) mission since GOES-1 launched in 1975. XRS measures solar irradiance in the X-ray region in 2 bandpasses, at 0.05-0.4 nm (short channel) and 0.1-0.8 nm (long channel). The GOES XRS data is used by the NOAA Space Weather Prediction Center (SWPC) to forecast the effects of space weather phenomena on Earth, and is also used by solar scientists to understand the statistics and dynamics of solar flares. This poster discusses science-quality data from GOES 1-18. We are currently reprocessing the GOES 8-12 XRS data to create a science-quality data set. This reprocessing removes the incorrect "SWPC scaling factor" adjustment to the GOES 1-15 irradiances, corrects the bandpass calibration, sets data quality flags, smooths the calibrations, standardizes file formats, and fills in data gaps, all of which have already been done for the science-quality GOES 13-18 data sets. Additionally, we present plans for completion of the GOES 1-7 XRS science-quality data, and for future new XRS data products.
Alessandra Pacini NOAA/NCEI (1) NOAA-NCEI, Boulder, CO,             
(2) CU-CIRES/NOAA-NCEI, Boulder, CO,   
(3) NOAA-NCAI, Boulder, CO
NOAA's Space Weather Follow On (SWFO) program: overview and current status We present an overview and current status of the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Follow On (SWFO) Program and discuss the importance of the SWFO's data products for the Heliophysics community. SWFO Program will ensure continuity of space weather operational data in the solar wind, providing advanced heliospheric observing capabilities from the Lagrange Point L1 and the geostationary orbit. The SWFO-L1 spacecraft will be launched in 2025, hosting a Solar Wind Plasma Sensor (SWiPS), a Magnetometer (MAG), a SupraThermal Ion Sensor (STIS) and a Compact Coronagraph (CCOR), enabling continuity of Coronal Mass Ejections (CMEs) and solar wind observations from NOAA's Deep Space Climate Observatory (DSCOVR), NASA's Advanced Composition Explorer (ACE) and NASA-ESA Solar and Heliospheric Observatory (SOHO) which are well past their designed lifetime. A second coronagraph (CCOR-1) will fly on the next Geostationary Operational Environmental Satellite to be launched in 2024 (GOES-U) and will add operational resilience to the CME imagery necessary for space weather monitoring and forecasts.
Alin Paraschiv National Solar Observatory National Solar Observatory/High Altitude Observatory Can we Infer Solar Coronal 3D Magnetic Fields using IQU-only Spectropolarimetry? With the upcoming commission of new generation instrumentation coupled with recent advances in understanding the theoretical aspects of solar coronal polarization, new science interpretation and inversion methods for polarized infrared observations is paramount.
Routinely measuring full Stokes polarization of forbidden lines formed in the solar corona is challenging. We propose to separate the problem of inverting coronal vector magnetic fields into two parts: i. Utilizing Stokes IQU observations to disentangling the magnetic field orientation via the newly developed CLEDB inversion code; ii. Estimating the magnetic field strength via magnetically-induced Doppler plasma oscillations. Thus, the vector magnetic field can be inferred without the formal need of including Stokes V circular polarization observations.
We present such a method for inferring the geometrical, thermal and vector magnetic information of coronal features, that can be applied to CoMP, uCoMP, DKIST Cryo-NIRSP, DL-NIRSP and others, by using infrared observations of intensity and linear polarization only, of at least two coronal M1 emission lines, like the Fe XIII 1074.68 nm and 1079.79 nm pair. 
Matthias Rempel HAO/NCAR (1) High Altitude Observatory, National Center for Atmospheric Research,                 
(2) Lockheed Martin Solar and Astrophysics Laboratory,               
(3) CSIRO, Space & Astronomy,               
(4) Astronomical Institute of the University of Bern
Comprehensive Radiative MHD Simulations of Eruptive Flares above Collisional Polarity Inversion Lines We present a series of simulations using the MURaM radiative Magnetohydrodynamic (MHD) code that allow to study the formation of collisional polarity inversion lines (cPILs) in the photosphere and the coronal response including flares. In simpler bipolar setups we study the dependence on parameters such as the collision speed and collision distance. While all setups lead to the formation of an EUV and X-ray sigmoid structure, only the cases with a close passing of the spots cause flares and mass eruptions in the upper C-class to lower M-class range. We find different timings in the transition from a sheared magnetic arcade (SMA) to magnetic flux rope (MFR) depending on the length and persistence of the cPIL; the setup with a large length but shorter duration cPIL produces a MFR during the eruption, while the MFR is pre-existing in the setup with a large length and longer duration cPIL. While both result in flares of comparable strength and the eruption of a CME, the setup with pre-existing MFR (and embedded filament) leads to an MFR eruption with a larger mass content. We present a quadrupolar setup inspired by AR11158, which leads to an X5.6 flare followed by several smaller flares in the C-class to M-class range.
Benjamin Short LASP/CU (1) CU Boulder Department of Physics,
(2) CU Boulder APS Department,             
(1,2) Laboratory for Atmospheric and Space Physics
Parker Solar Probe Observations of Quiescent Regions in the Near-Sun Solar Wind. During each of its 16 orbits around the Sun, Parker Solar Probe has observed regions with Parker spiral-like field geometries which contain low amplitude Alfvenic fluctuations called quiescent regions. Using the deflection angle between a Parker-spiral calculated from the local solar wind speed and the measured magnetic field we identify 507 quiescent regions for orbits 1 through 16. The events identified in this study cover a radial range of 13.3 solar radii (Rs) to 45 Rs. Using these identified times, we analyze the thermal properties of these regions using the SPAN-Ion instrument on Parker Solar Probe. In this study we attempt to quantify the evolution of quiescent regions as they travel outward through the solar wind near the Sun. By looking at the temperature anisotropy and plasma beta, we compare both quiescent solar wind and non-quiescent solar wind plasma to plasma instability thresholds. Results suggest that quiescent regions possess thermal properties consistent with less evolved solar wind and take a different path through the parameter space as they propagate outward into space. The completion of this study will help us understand better the processes which govern the evolution of the solar wind and may allow us to probe the role of turbulence in heating and acceleration.
Cole Tamburri CU/LASP/NSO (1) University of Colorado, Boulder;   
(2) Laboratory for Atmospheric and Space Physics;         
(3) National Solar Observatory
Probing Chromospheric Dynamics with DKIST Observations of a C-class Solar Flare Recent advances in our understanding of solar and stellar flares have revealed several unexplained phenomena in flare dynamics. For example, in red dwarf flares, the hydrogen Balmer lines peak in intensity earlier and are much broader when compared to Ca II lines. Solar flare data appear to follow a similar pattern, but have, until now, been of insufficient resolution to provide an explanation. There also remain unexplained differences between the simulated and observed evolution and intensity of the red-shifted component of chromospheric lines. To address these remaining questions, we obtained observations of the GOES class C6.7 solar flare SOL2022-08-19T20:31 and other flares and brightenings between 15 August 2022 and 25 August 2022 from the Daniel K. Inouye Solar Telescope (DKIST) Visible Spectro-polarimeter (ViSP) and Visible Broadband Imager (VBI). In this work, we analyze spectral line evolution in the Ca II H 396.8 nm and H-epsilon 397.0 nm lines from ViSP observations. We describe the data calibration and processing unique to fulfilling our science goals. We compare the equivalent widths, effective widths, and broadening of the Ca II H and H-epsilon lines at several flaring locations along the ViSP slit in order to constrain the relative amounts of turbulent, velocity, and pressure broadening. We investigate the presence of a double-component structure in Ca II H in order to better understand the details of chromospheric condensation. We discuss how these data will facilitate interpretation of spatially unresolved observations of the same wavelength regions in stellar flares and outline future avenues for analysis. Results from this study will inform the next generation of 1D radiative-hydrodynamic flare models by placing constraints on the details of electron and proton pressure broadening profiles.
Peter Tatum LASP/CU University of Colorado, Boulder/Laboratory for Atmospheric and Space Phsyics Switchback Sources of Kinetic Alfen Wave Power in the near-Sun Solar Wind The solar wind has been observed to heat internally as it expands outward from the Sun, but the nature of this heating has not yet been fully characterized. One primary mechanism for heating comes from turbulent fluctuations that can carry energy from large scales to kinetic scales. Recent solar wind observations at 1AU show the presence of KAWs below inertial range scales, suggesting that they play a role in energy dissipation. Understanding how KAWs are generated and evolve closer to the Sun can help elucidate their role in the radial evolution of solar wind. We present observations of KAWs in the near-sun environment (0.074 AU) using Parker Solar Probe. We show that KAW wave power is spatially correlated with intermittent large-scale Alfvénic fluctuations (including Switchbacks) that be act as source regions for KAWs. We take advantage of this spatial inhomogeneity to estimate the decay rate of the KAW fluctuations as they propagate away from their source.
Dennis Tilipman CU/NSO (1) CU/NSO,             
Using Numerical MHD Simulations to Improve Photospheric Electric Field and Poynting Flux Inversion Methods Photosperic electric fields and Poynting flux are both crucial to energy transport in the solar atmosphere. However, these quantities are not easily derived from observations, even with the data from the most advanced observatories such as DKIST or SO. Uncertainties arise from limited polarimetric sensitivity and from the effects of limited spatial and temporal resolutions, and no instrument can optimize for all three of these simultaneously. The goal of this work is to characterize the propagation of these respective uncertainties, currently with a focus on spatial and temporal effects. In the future we plan to use our findings to design observation strategies optimized for retrieval of electric fields.
Electric field and Poynting flux inversions require the magnetic field and velocity field vectors as intermediate quantities. This presents a problem in observations, since v- and B-fields are observed on optical surfaces, but their derivatives and vector products are computed on geometrical surfaces. Thus, another component of our work is to explore the effect of this discrepancy at different spatial and temporal resolutions.
For these preliminary explorations, we use the outputs of MURaM 3-D MHD simulations containing an active region and the quiet Sun. They are especially suitable for our purposes since they are computed on both height and optical depth grid. We degrade the native MURaM spatial resolution and cadence using a variety of methods.
Our preliminary results indicate that spatial resolution effects are generally more important than the cadence effects, though this depends on the target of observations. We also report that the effects of computing electric fields on the optical rather than geometrical surfaces are outweighed by degraded spatial resolution and cadence. We emphasize, however, that this is a work in progress.
Regner Trampedach SSI Space Science Institute A First Look at Helioseismic Abundances with New T-MHD EOS A new equation of state (EOS) has been developed, based on the venerable MHD EOS, developed here at HAO. I will show the first application of this EOS to astrophysical problems, by presenting a helioseismic optimization of helium-, Y, and metal-, Z, abundances.
Benoit Tremblay HAO/NCAR (1) High Altitude Observatory,
(2) University of Graz,
(3) Imperial College London, 
(4) Massachusetts Institute of Technology,
(5) European Space Agency, 
(6) Intel Labs, 
(7) Applied Physics Lab. Johns Hopkins University,
(8) Applied Physics Lab. Johns Hopkins,
(9) Southwest Research Institute
Enhancing Observational Capabilities of EUV-observing Satellites to Estimate Spectral Irradiance Multiple satellites capture images of the Sun in Extreme Ultraviolet (EUV) light. However, only the Solar Dynamics Observatory (SDO) was equipped with instruments that measure the Sun's spectral irradiance (i.e., MEGS-A and MEGS-B onboard the Extreme ultraviolet Variability Experiment (EVE) suite). The MEGS-A instrument malfunctioned back in 2014, making it impossible to measure the full irradiance spectrum since.

Using AI, we explore the translation of a set of EUV images of the Sun into spectral irradiance, effectively replacing the malfunctioning MEGS-A instrument onboard SDO. In other words, we generate a virtual irradiance instrument, MEGS-AI, for SDO. Additionally, this virtual instrument can be trained and added on other EUV-observing satellites like the STEREO, GOES, SolO, and VIGIL satellites, enabling them to estimate irradiance from their EUV images despite not having the proper instrumentation to do so. Finally, when combined with a neural radiance field model of the Sun, MEGS-AI can estimate spectral irradiance from any viewpoint and can, for example, be used to estimate the Sun's impact on other planets in the solar system. 

Kiera van der Sande SwRI Southwest Research Institute Regression-based flare forecasting using historical magnetograms The majority of machine-learning (ML) flare forecasting models focus on a binary classification task: will there be a flare within a given forecast window or not? This task requires fixing a threshold for what constitutes a positive flaring event, which is commonly defined as flares with a maximum X-ray irradiance of 1e-5 W/m2  (M1 or larger flares), or a maximum of 1e-6 W/m2  (C1 or larger flares).  However, this introduces a challenge for any machine learning model to differentiate between a flare just below the threshold and a flare over the threshold. Additionally, forecasters often want to know not just whether an event will occur, but how likely it is to occur and how large it will be. Given the lack of substantive advances in binary flare forecasting using ML, we consider recasting the forecasting problem as a regression task. We train ML models to output a full disk-forecast of the maximum X-ray irradiance within a given window. This definition moves beyond forecasting flare intensity to include the variable background flux during quiet periods, which are often artificially labeled as zeros for models that do predict flare intensities. Here we compare several ML models on our regression task. As inputs, we use historical magnetogram data from instruments spanning back to 1970. Including historical data increases the number of flare events for training by an order of magnitude compared to training only on modern data, i.e., from SDO/HMI. We leverage model pretraining techniques to take advantage of prior work on probabilistic classification models and use model ensembles to quantify uncertainty.  
Tania  Varesano CU/SwRI (1) CU Boulder
(2) Southwest Research Institute
(3) NASA Goddard Space Flight Center
Linking the Sun's surface and the heliosphere with  SPICE's composition mosaics We present an analysis of the first connection mosaic made by the SPICE instrument on board of the ESA / NASA Solar Orbiter mission on March 2, 2022. The data will be used to map coronal composition that will be compared with in-situ measurements taken by SWA/HIS  to establish the coronal origin of the solar wind plasma observed at Solar Orbiter. The SPICE spectral lines were chosen to have varying sensitivity to the First Ionization Potential (FIP) effect, and therefore the radiances of the spectral lines will vary significantly depending on whether the elemental composition is coronal or photospheric.

We perform temperature diagnostics using line ratios and Emission Measure (EM) loci, and compute relative FIP biases using three different approaches (two line ratio (2LR), ratios of linear combinations of spectral lines (LCR), and differential emission measure (DEM) inversion) in order to perform composition diagnostics in the corona. We then compare the SPICE composition analysis and EUI data of the potential solar wind sources regions to the SWA / HIS data products.

Radiance maps are extracted from SPICE spectral data cubes, with values matching previous observations. We find isothermal plasma of around LogT=5.8 for the active region loops targeted, and that higher FIP-bias values are present at the footpoints of the coronal loops associated with two active regions.

Andres  Villani Davila LASP/CU CU Boulder/Laboratory for Atmospheric and Space Physics (LASP) Finite Element Analysis of TIM's Equivalence Ratio Accurate measurements of total solar irradiance (TSI) are vital for understanding the Earth's climate, predicting space weather events, optimizing solar energy applications, and studying solar variability. The current state-of-the-art data record of TSI has been provided by different iterations of the Total Irradiance Monitor (TIM) onboard the SORCE, TCTE and TSIS-1 missions, and will be continued as its latest version flies in TSIS-2 by the end of 2024. TIM is an electrical substitution radiometer, it quantifies optical power in a black cavity by measuring a proportional electrical power difference that keeps its temperature fixed. The proportionality constant, or "equivalence ratio", is critical for interpreting the TIM measurements. However, it is also the most poorly characterized calibration parameter of TIM. By definition, the only way to directly measure it requires knowing the input optical power with considerably higher certainty than that of TIM itself, but no instrument is capable of achieving that accuracy at present. Current estimates of TIM's equivalence ratio have been obtained from analytical expressions with important approximations and on-orbit measurements capable of estimating its AC behavior, but not the DC or steady state value. We present a different approach using high fidelity finite element analysis of the instrument. Simulations are validated with empirical data, and the uncertainty is estimated through a Monte Carlo approach. 
Matthew West SwRI (1) Southwest Research Institute,   
(2) High Altitude Observatory
Resolving CME Characteristics with Polarized White Light Data The Polarimeter to UNify the Corona and Heliosphere (PUNCH) mission will explore the largely unexplored region of the heliosphere from the middle corona out to 1 AU: i.e., the "young solar wind", through direct, global, spatially continuous, and 3D deep-field imaging. This is achieved through Brightness (B) and polarized brightness (pB) measurements, which is analogous to the Stokes system in solar observing coordinates. PUNCH will be able to study the propagation of coronal mass ejections (CMEs) throughout the heliosphere, and in particular the chirality of CMEs, which can be determined directly from physics of Thomson scattering applied to synoptic polarized images. One difficulty in accurately determining the positions of structures lies in the impact of noise, and requires relative photometry accuracy at a few percent precision.

PUNCH will use a symmetric three-polarizer measurement and representation system to derive the Stokes parameters. As part of the PUNCH development project a universal polarization resolver has been built together with tools to characterize noise in polarimetric response (see presentation: "A New Universal Polarization Resolving Software Package for Solar Coronal and Heliospheric Observations" by Walbridge et al.). In this presentation the potential ability to accurately measure the 3D structure of imaged objects in the heliosphere with PUNCH will be assessed. "Clean" synthetic data from the Gamera model, forward modelled to look like PUNCH data using the HAO FORWARD algorithms will be used with the polarization resolver to determine the chirality of synthetic CMEs. Additionally, realistic photometric (poisson) and instrument noise will be applied to the data to assess the impact on the estimated positions of structures, with comparisons made to the clean datasets. The noisy data will be subsequently "noise-gated" to reduce noise and mitigate its impact. The impacts of noise reduction, and how it can improve estimates of 3D position are also assessed.

Maurice Wilson HAO/NCAR High Altitude Observatory The magnetic and thermodynamic morphology of CMEs with UCoMP at MLSO The mechanism for the storage and release of magnetic energy in coronal mass ejections (CMEs) remains a major unsolved problem of Heliophysics. Thus, observations of the coronal magnetic field before, during, and after the eruption are important both for scientific progress and space weather predictions. We use the newly built Upgraded Coronal Multichannel Polarimeter (UCoMP) instrument from the Mauna Loa Solar Observatory (MLSO) to study the magnetic and thermodynamic morphology of CME precursors and eruptions. With this coronagraph's 20-cm aperture and field of view extending from 1.05 to 2.0 solar radii, we determine the magnetic field orientation of pre- and post-CME coronal loops using Stokes Q and U parameters as derived from the linearly polarized radiation observed from the Fe XIII 1074 nm spectral line. To ascertain the density, temperature, and ionization distribution of the hot plasma, we compare and contrast the structures seen at 1074 nm with the coronal features observed by UCoMP at the Fe X 637 nm line, the Fe XV 706 nm line, the Fe XI 789 nm line, and the Fe XIII 1079 nm line. In this study, we use several CME precursors and eruptions as examples for showcasing the unique capabilities of UCoMP, which will inform the future of ground-based coronograph polarimeter observations that will eventually be performed with the COronal Solar Magnetism Observatory (COSMO).
Rahul Yadav LASP/CU [1] Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder;
[2] National Solar Observatory, Boulder;
[3] Stockholm University, Sweden
Atmospheric Heating Due to Small-scale Events in an Emerging Flux Region We investigate the thermal, kinematic and magnetic structure of small-scale heating events in an emerging flux region (EFR). We use high-resolution multi-line observations (including Ca II 854.2 nm Ca II K, and the Fe I 630.1 nm line pair) of an EFR located close to the disk center from the CRISP and CHROMIS instruments at the Swedish 1-m Solar Telescope. We perform non-LTE inversions of multiple spectral lines to infer the temperature, velocity, and magnetic field structure of the heating events. Additionally, we use the data-driven Coronal Global Evolutionary Model to simulate the evolution of the 3D magnetic field configuration above the events and understand their dynamics. Furthermore, we analyze the differential emission measure to gain insights into the heating of the coronal plasma in the EFR. Our analysis  reveals the presence of numerous small-scale heating events in the EFR, primarily located at polarity inversion lines of bipolar structures. These events not only heat the lower atmosphere but also significantly heat the corona. The data-driven simulations, along with the observed enhancement of currents and Poynting flux, suggest that magnetic reconnection in the lower atmosphere is likely responsible for the observed heating at these sites.
Padma Yanamandra-Fisher SSI SSI   We discuss the polariazation of 2017 TSE