arXiv subjects

Jack Ireland

Publications and source records attributed to Jack Ireland.

At least 19 recordsLinked to original sources

arXiv2026

HDRL Staff Strategy Meeting Report

HDRL held its first HDRL wide strategy meeting in January 2026, pulling in a majority of HDRL member staff and selected HDRL grantees. Just over 40 people attended with a few more online to listen to over 30 lightning talks presented by their colleagues and leaders, participate in several breakout and group discussions, and cast 324 votes on over 50 strategic topic ideas contributed by the attendees. The many ideas generated by attendees can be grouped into seven themes which describe the overall breadth of discussion at the meeting. These themes included: Metadata, Standards, and Semantics Discovery, Search, and Recommendation Modernizing HDRL User experience Modernizing HDRL Staff experience Modernized, Scalable, and Dependable Infrastructure for Compute and Storage Metrics and Impact Assessment Community Engagement and Sustainability Considering the gathered information and the interconnections between the prioritized ideas we concluded that several strategic areas for action exist. This document provides an overview of contributed materials and post meeting strategic analysis.

astro-ph.IM↗

arXiv2023

The Focusing Optics X-ray Solar Imager (FOXSI)

FOXSI is a direct-imaging, hard X-ray (HXR) telescope optimized for solar flare observations. It detects hot plasma and energetic electrons in and near energy release sites in the solar corona via bremsstrahlung emission, measuring both spatial structure and particle energy distributions. It provides two orders of magnitude faster imaging spectroscopy than previously available, probing physically relevant timescales (<1s) never before accessible to address fundamental questions of energy release and efficient particle acceleration that have importance far beyond their solar application (e.g., planetary magnetospheres, flaring stars, accretion disks). FOXSI measures not only the bright chromospheric X-ray emission where electrons lose most of their energy, but also simultaneous emission from electrons as they are accelerated in the corona and propagate along magnetic field lines. FOXSI detects emission from high in the tenuous corona, where previous instruments have been blinded by nearby bright features and will fully characterizes the accelerated electrons and hottest plasmas as they evolve in energy, space, and time to solve the mystery of how impulsive energy release leads to solar eruptions, the primary drivers of space weather at Earth, and how those eruptions are energized and evolve.

astro-ph.IM↗

arXiv2023

Fundamentals of impulsive energy release in the corona

It is essential that there be coordinated and co-optimized observations in X-rays, gamma-rays, and EUV during the peak of solar cycle 26 (~2036) to significantly advance our understanding of impulsive energy release in the corona. The open questions include: What are the physical origins of space-weather events? How are particles accelerated at the Sun? How is impulsively released energy transported throughout the solar atmosphere? How is the solar corona heated? Many of the processes involved in triggering, driving, and sustaining solar eruptive events -- including magnetic reconnection, particle acceleration, plasma heating, and energy transport in magnetized plasmas -- also play important roles in phenomena throughout the Universe. This set of observations can be achieved through a single flagship mission or, with foreplanning, through a combination of major missions (e.g., the previously proposed FIERCE mission concept).

astro-ph.IM↗

arXiv2023

The SunPy Project: An Interoperable Ecosystem for Solar Data Analysis

The SunPy Project is a community of scientists and software developers creating an ecosystem of Python packages for solar physics. The project includes the sunpy core package as well as a set of affiliated packages. The sunpy core package provides general purpose tools to access data from different providers, read image and time series data, and transform between commonly used coordinate systems. Affiliated packages perform more specialized tasks that do not fall within the more general scope of the sunpy core package. In this article, we give a high-level overview of the SunPy Project, how it is broader than the sunpy core package, and how the project curates and fosters the affiliated package system. We demonstrate how components of the SunPy ecosystem, including sunpy and several affiliated packages, work together to enable multi-instrument data analysis workflows. We also describe members of the SunPy Project and how the project interacts with the wider solar physics and scientific Python communities. Finally, we discuss the future direction and priorities of the SunPy Project.

astro-ph.SR↗

arXiv2023

Science Platforms for Heliophysics Data Analysis

We recommend that NASA maintain and fund science platforms that enable interactive and scalable data analysis in order to maximize the scientific return of data collected from space-based instruments.

astro-ph.IM↗

arXiv2022

Deep Learning for Space Weather Prediction: Bridging the Gap between Heliophysics Data and Theory

Traditionally, data analysis and theory have been viewed as separate disciplines, each feeding into fundamentally different types of models. Modern deep learning technology is beginning to unify these two disciplines and will produce a new class of predictively powerful space weather models that combine the physical insights gained by data and theory. We call on NASA to invest in the research and infrastructure necessary for the heliophysics' community to take advantage of these advances.

astro-ph.IM↗

arXiv2021

Evaluating Pointing Strategies for Future Solar Flare Missions

Solar flares are events of intense scientific interest. Although certain solar conditions are known to be associated with flare activity, the exact location and timing of an individual flare on the Sun cannot as yet be predicted with certainty. Missions whose science objectives depend on observing solar flares must often make difficult decisions on where to target their observations if they do not observe the full solar disk. Yet, little analysis exists in the literature which might guide these missions' operations to maximize their opportunities to observe flares. In this study we analyze and simulate the performance of different observation strategies using historical flare and active region data from 2011 to 2014. We test a number of different target selection strategies based on active region complexity and recent flare activity, each of which is examined under a range of operational assumptions. In each case we investigate various metrics such as the number of flares observed, the size of flares observed, and operational considerations such as the number of instrument re-points that are required. Overall, target selection methods based on recent flare activity showed the best overall performance, but required more repointings than other methods. The mission responsiveness to new information is identified as a strong factor determining flare observation performance. It is also shown that target selection methods based on active region complexities show a significant pointing bias towards the western solar hemisphere. The number of flares observed grows quickly with field-of-view size until the approximate size of an active region is reached, but further improvements beyond the active region size are much more incremental. These results provide valuable performance estimates for a future mission focused on solar flares, and inform the requirements that would ensure mission success.

astro-ph.SR↗

arXiv2020

Machine Learning in Heliophysics and Space Weather Forecasting: A White Paper of Findings and Recommendations

The authors of this white paper met on 16-17 January 2020 at the New Jersey Institute of Technology, Newark, NJ, for a 2-day workshop that brought together a group of heliophysicists, data providers, expert modelers, and computer/data scientists. Their objective was to discuss critical developments and prospects of the application of machine and/or deep learning techniques for data analysis, modeling and forecasting in Heliophysics, and to shape a strategy for further developments in the field. The workshop combined a set of plenary sessions featuring invited introductory talks interleaved with a set of open discussion sessions. The outcome of the discussion is encapsulated in this white paper that also features a top-level list of recommendations agreed by participants.

astro-ph.SR↗

arXiv2020

A Survey of Computational Tools in Solar Physics

The SunPy Project developed a 13-question survey to understand the software and hardware usage of the solar physics community. 364 members of the solar physics community, across 35 countries, responded to our survey. We found that 99$\pm$0.5% of respondents use software in their research and 66% use the Python scientific software stack. Students are twice as likely as faculty, staff scientists, and researchers to use Python rather than Interactive Data Language (IDL). In this respect, the astrophysics and solar physics communities differ widely: 78% of solar physics faculty, staff scientists, and researchers in our sample uses IDL, compared with 44% of astrophysics faculty and scientists sampled by Momcheva and Tollerud (2015). 63$\pm$4% of respondents have not taken any computer-science courses at an undergraduate or graduate level. We also found that most respondents utilize consumer hardware to run software for solar-physics research. Although 82% of respondents work with data from space-based or ground-based missions, some of which (e.g. the Solar Dynamics Observatory and Daniel K. Inouye Solar Telescope) produce terabytes of data a day, 14% use a regional or national cluster, 5% use a commercial cloud provider, and 29% use exclusively a laptop or desktop. Finally, we found that 73$\pm$4% of respondents cite scientific software in their research, although only 42$\pm$3% do so routinely.

astro-ph.IM↗

arXiv2019

Persistent Quasi-Periodic Pulsations During a Large X-Class Solar Flare

Solar flares often display pulsating and oscillatory signatures in the emission, known as quasi-periodic pulsations (QPP). QPP are typically identified during the impulsive phase of flares, yet in some cases, their presence is detected late into the decay phase. Here, we report extensive fine structure QPP that are detected throughout the large X8.2 flare from 2017 September 10. Following the analysis of the thermal pulsations observed in the GOES/XRS and the 131 A channel of SDO/AIA, we find a pulsation period of ~65 s during the impulsive phase followed by lower amplitude QPP with a period of ~150 s in the decay phase, up to three hours after the peak of the flare. We find that during the time of the impulsive QPP, the soft X-ray source observed with RHESSI rapidly rises at a velocity of approximately 17 km/s following the plasmoid/coronal mass ejection (CME) eruption. We interpret these QPP in terms of a manifestation of the reconnection dynamics in the eruptive event. During the long-duration decay phase lasting several hours, extended downward contractions of collapsing loops/plasmoids that reach the top of the flare arcade are observed in EUV. We note that the existence of persistent QPP into the decay phase of this flare are most likely related to these features. The QPP during this phase are discussed in terms of MHD wave modes triggered in the post-flaring loops.

astro-ph.SR↗

arXiv2018

Roadmap for Reliable Ensemble Forecasting of the Sun-Earth System

The authors of this report met on 28-30 March 2018 at the New Jersey Institute of Technology, Newark, New Jersey, for a 3-day workshop that brought together a group of data providers, expert modelers, and computer and data scientists, in the solar discipline. Their objective was to identify challenges in the path towards building an effective framework to achieve transformative advances in the understanding and forecasting of the Sun-Earth system from the upper convection zone of the Sun to the Earth's magnetosphere. The workshop aimed to develop a research roadmap that targets the scientific challenge of coupling observations and modeling with emerging data-science research to extract knowledge from the large volumes of data (observed and simulated) while stimulating computer science with new research applications. The desire among the attendees was to promote future trans-disciplinary collaborations and identify areas of convergence across disciplines. The workshop combined a set of plenary sessions featuring invited introductory talks and workshop progress reports, interleaved with a set of breakout sessions focused on specific topics of interest. Each breakout group generated short documents, listing the challenges identified during their discussions in addition to possible ways of attacking them collectively. These documents were combined into this report-wherein a list of prioritized activities have been collated, shared and endorsed.

astro-ph.SR↗

arXiv2018

AWARE: An algorithm for the automated characterization of EUV waves in the solar atmosphere

Extreme ultraviolet (EUV) waves are large-scale propagating disturbances observed in the solar corona, frequently associated with coronal mass ejections and flares. They appear as faint, extended structures propagating from a source region across the structured solar corona. Since their discovery, over two hundred papers discussing their properties, causes and physical nature have been published. However, despite this their fundamental properties and the physics of their interactions with other solar phenomena are still not understood. To further the understanding of EUV waves, we have constructed the Automated Wave Analysis and REduction (AWARE) algorithm for the measurement of EUV waves. AWARE is implemented in two stages. In the first stage, we use a new type of running difference image, the running difference persistence image, which enables the efficient isolation of propagating, brightening wavefronts as they propagate across the corona. In the second stage, AWARE detects the presence of a wavefront, and measures the distance, velocity and acceleration of that wavefront across the Sun. The fit of propagation models to the wave progress isolated in the first stage is achieved using the Random Sample and Consensus (RANSAC) algorithm. AWARE is tested against simulations of EUV wave propagation, and is applied to measure EUV waves in observational data from the Atmospheric Imaging Assembly (AIA). We also comment on unavoidable systematic errors that bias the estimation of wavefront velocity and acceleration. In addition, the full AWARE software suite comes with a package that creates simulations of waves propagating across the disk from arbitrary starting points.

astro-ph.SR↗

arXiv2017

On the Performance of Multi-Instrument Solar Flare Observations During Solar Cycle 24

The current fleet of space-based solar observatories offers us a wealth of opportunities to study solar flares over a range of wavelengths. Significant advances in our understanding of flare physics often come from coordinated observations between multiple instruments. Consequently, considerable efforts have been, and continue to be made to coordinate observations among instruments (e.g. through the Max Millennium Program of Solar Flare Research). However, there has been no study to date that quantifies how many flares have been observed by combinations of various instruments. Here we describe a technique that retrospectively searches archival databases for flares jointly observed by RHESSI, SDO/EVE (MEGS-A and -B), Hinode/(EIS, SOT, and XRT), and IRIS. Out of the 6953 flares of GOES magnitude C1 or greater that we consider over the 6.5 years after the launch of SDO, 40 have been observed by six or more instruments simultaneously. Using each instrument's individual rate of success in observing flares, we show that the numbers of flares co-observed by three or more instruments are higher than the number expected under the assumption that the instruments operated independently of one another. In particular, the number of flares observed by larger numbers of instruments is much higher than expected. Our study illustrates that these missions often acted in cooperation, or at least had aligned goals. We also provide details on an interactive widget now available in SSWIDL that allows a user to search for flaring events that have been observed by a chosen set of instruments. This provides access to a broader range of events in order to answer specific science questions. The difficulty in scheduling coordinated observations for solar-flare research is discussed with respect to instruments projected to begin operations during Solar Cycle 25, such as DKIST, Solar Orbiter, and Parker Solar Probe.

astro-ph.SR↗

arXiv2017

Pulsations in the Earth's Lower Ionosphere Synchronized with Solar Flare Emission

Solar flare emission at X-ray and extreme ultraviolet (EUV) energies can cause substantial enhancements in the electron density in the Earth's lower ionosphere. It is now become clear that flares exhibit quasi-periodic pulsations with timescales of minutes at X-ray energies, but to date, it has not been known if the ionosphere is sensitive to this variability. Here, using a combination of Very Low Frequency (24 kHz) measurement together with space-based X-ray and EUV observations, we report pulsations of the ionospheric D-region, which are synchronized with a set of pulsating flare loops. Modeling of the ionosphere show that the D-region electron density varies by up to an order of magnitude over the timescale of the pulsations ($\sim$20 mins). Our results reveal that the Earth's ionosphere is more sensitive to small-scale changes in solar soft X-ray flux than previously thought, and implies that planetary ionospheres are closely coupled to small-scale changes in solar/stellar activity.

physics.space-ph↗

arXiv2017

Detection of 3-Minute Oscillations in Full-Disk Ly$α$ Emission During A Solar Flare

In this Letter we report the detection of chromospheric 3-minute oscillations in disk-integrated EUV irradiance observations during a solar flare. A wavelet analysis of detrended Lyman-alpha (from GOES/EUVS) and Lyman continuum (from SDO/EVE) emission from the 2011 February 15 X-class flare (SOL2011-02-15T01:56) revealed a $\sim$3-minute period present during the flare's main phase. The formation temperature of this emission locates this radiation to the flare's chromospheric footpoints, and similar behaviour is found in the SDO/AIA 1600Å and 1700Å channels, which are dominated by chromospheric continuum. The implication is that the chromosphere responds dynamically at its acoustic cutoff frequency to an impulsive injection of energy. Since the 3-minute period was not found at hard X-ray energies (50-100 keV) in RHESSI data we can state that this 3-minute oscillation does not depend on the rate of energization of non-thermal electrons. However, a second period of 120 s found in both hard X-ray and chromospheric emission is consistent with episodic electron energization on 2-minute timescales. Our finding on the 3-minute oscillation suggests that chromospheric mechanical energy should be included in the flare energy budget, and the fluctuations in the Lyman-alpha line may influence the composition and dynamics of planetary atmospheres during periods of high activity.

astro-ph.SR↗

arXiv2017

Detection and Interpretation Of Long-Lived X-Ray Quasi-Periodic Pulsations in the X-Class Solar Flare On 2013 May 14

Quasi-periodic pulsations (QPP) seen in the time derivative of the GOES soft X-ray light curves are analyzed for the near-limb X3.2 event on 14 May 2013. The pulsations are apparent for a total of at least two hours from the impulsive phase to well into the decay phase, with a total of 163 distinct pulses evident to the naked eye. A wavelet analysis shows that the characteristic time scale of these pulsations increases systematically from $\sim$25 s at 01:10 UT, the time of the GOES peak, to $\sim$100 s at 02:00 UT. A second ridge in the wavelet power spectrum, most likely associated with flaring emission from a different active region, shows an increase from $\sim$40 s at 01:40 UT to $\sim$100 s at 03:10 UT. We assume that the QPP that produced the first ridge result from vertical kink-mode oscillations of the newly formed loops following magnetic reconnection in the coronal current sheet. This allows us to estimate the magnetic field strength as a function of altitude given the density, loop length, and QPP time scale as functions of time determined from the GOES light curves and RHESSI images. The calculated magnetic field strength of the newly formed loops ranges from about $\sim$500 G at an altitude of 24 Mm to a low value of $\sim$10 G at 60 Mm, in general agreement with the expected values at these altitudes. Fast sausage mode oscillations are also discussed and cannot be ruled out as an alternate mechanism for producing the QPP.

astro-ph.SR↗

arXiv2017

Exploring impulsive solar magnetic energy release and particle acceleration with focused hard X-ray imaging spectroscopy

How impulsive magnetic energy release leads to solar eruptions and how those eruptions are energized and evolve are vital unsolved problems in Heliophysics. The standard model for solar eruptions summarizes our current understanding of these events. Magnetic energy in the corona is released through drastic restructuring of the magnetic field via reconnection. Electrons and ions are then accelerated by poorly understood processes. Theories include contracting loops, merging magnetic islands, stochastic acceleration, and turbulence at shocks, among others. Although this basic model is well established, the fundamental physics is poorly understood. HXR observations using grazing-incidence focusing optics can now probe all of the key regions of the standard model. These include two above-the-looptop (ALT) sources which bookend the reconnection region and are likely the sites of particle acceleration and direct heating. The science achievable by a direct HXR imaging instrument can be summarized by the following science questions and objectives which are some of the most outstanding issues in solar physics (1) How are particles accelerated at the Sun? (1a) Where are electrons accelerated and on what time scales? (1b) What fraction of electrons is accelerated out of the ambient medium? (2) How does magnetic energy release on the Sun lead to flares and eruptions? A Focusing Optics X-ray Solar Imager (FOXSI) instrument, which can be built now using proven technology and at modest cost, would enable revolutionary advancements in our understanding of impulsive magnetic energy release and particle acceleration, a process which is known to occur at the Sun but also throughout the Universe.

astro-ph.SR↗

arXiv2016

Quasi-Periodic Pulsations during the Impulsive and Decay phases of an X-class Flare

Quasi-periodic pulsations (QPP) are often observed in X-ray emission from solar flares. To date, it is unclear what their physical origins are. Here, we present a multi-instrument investigation of the nature of QPP during the impulsive and decay phases of the X1.0 flare of 28 October 2013. We focus on the character of the fine structure pulsations evident in the soft X-ray time derivatives and compare this variability with structure across multiple wavelengths including hard X-ray and microwave emission. We find that during the impulsive phase of the flare, high correlations between pulsations in the thermal and non-thermal emissions are seen. A characteristic timescale of ~20s is observed in all channels and a second timescale of ~55s is observed in the non-thermal emissions. Soft X-ray pulsations are seen to persist into the decay phase of this flare, up to 20 minutes after the non-thermal emission has ceased. We find that these decay phase thermal pulsations have very small amplitude and show an increase in characteristic timescale from ~40s up to ~70s. We interpret the bursty nature of the co-existing multi-wavelength QPP during the impulsive phase in terms of episodic particle acceleration and plasma heating. The persistent thermal decay phase QPP are most likely connected with compressive MHD processes in the post-flare loops such as the fast sausage mode or the vertical kink mode.

astro-ph.SR↗