The relationship between supergranulation flows, magnetic field evolution and network flares

The quiet Sun may be the biggest laboratory to study physical elementary processes of fundamental importance to space plasma. The advantage is the continuous availability of small-scale events, carrying the hidden microphysics that is responsible for larger-scale phenomena. By small-scale events, we mean spatial dimensions of a few Mm at most, and durations of less than an hour. This thesis is an attempt to describe and understand the coupling between the photospheric flows, the photospheric magnetic flux, and small-scale energetic transient events. We adapted a highly efficient numerical method, called Balltracking, to derive the photospheric flows from images of the granulation. For studying the dynamics of magnetic flux, and more precisely, its cancellation at relevant sites, we developed a new tool called "Magnetic Balltracking", to track photospheric magnetic elements present in high-resolution magnetograms. In a multi-instrument study using observations of the low corona in soft X-rays, we analyse the triggering mechanism of small-scale network flares. Balltracking directly relates the flows with cancelling magnetic flux, while the latter is tracked with Magnetic Balltracking. We identify two patterns of horizontal flows that act as catalysts for efficient magnetic reconnection: Funnel-shaped streamlines in which the magnetic flux is carried, and large-scale vortices (>15 Mm) at the network intersections, in which distant magnetic features of opposite polarities are sucked in and ultimately cancel. The excess energy stored in the stressed magnetic field of the vortices is sufficient to power network flares

The SDO/EVE Solar Irradiance Coronal Dimming Index Catalog. I. Methods and Algorithms

When a coronal mass ejection departs, it leaves behind a temporary void. That void is known as coronal dimming, and it contains information about the mass ejection that caused it. Other physical processes can cause parts of the corona to have transient dimmings, but mass ejections are particularly interesting because of their influence in space weather. Prior work has established that dimmings are detectable even in disk-integrated irradiance observations, i.e., Sun-as-a-star measurements. The present work evaluates four years of continuous Solar Dynamics Observatory Extreme Ultraviolet Experiment (EVE) observations to greatly expand the number of dimmings we may detect and characterize, and collects that information into Jamess EVE Dimming Index catalog. This paper details the algorithms used to produce the catalog, provides statistics on it, and compares it with prior work. The catalog contains 5051 potential events (rows), which correspond to all robustly detected solar eruptive events in this time period as defined by >C1 flares. Each row has a corresponding 27,349 elements of metadata and parameterizations (columns). In total, this catalog is the result of analyzing 7.6 million solar ultraviolet light curves

Turning Noise Into Data: Characterization of the Van Allen Radiation Belt Using SDO Spikes Data

The Solar Dynamics Observatory (SDO) is a solar mission in an inclined geosynchronous orbit. Since commissioning, images acquired by Atmospheric Imaging Assembly (AIA) instrument on-board the SDO have frequently displayed “spikes,” pixel regions yielding extreme number of digital counts. These are theorized to occur from energetic electron collisions with the instrument detector system. These spikes are regularly removed from AIA Level 1.0 images to produce clean and reliable data. A study of historical data has found over 100 trillion spikes in the past decade. This project correlates spike detection frequency with radiation environment parameters in order to generate an augmented data product from SDO. We conduct a correlation study between SDO/AIA data and radiation belt activity within the SDO’s orbit. By extracting radiation “spike” data from the SDO/AIA images, we produce a comprehensive data product which is correlated not only with geomagnetic parameters such as Kp, Ap, and Sym-H but also with the electron and proton fluxes measured by the GOES-14 satellite. As a result, we find that AIA spikes are highly correlated with the GOES-14 electrons detected by the magnetospheric electron detector and energetic proton, electron and alpha detectors instruments at the equator (where the two satellites meet) with Spearman’s Correlation values of ρ = 0.73 and ρ = 0.53, respectively, while a weaker correlation of ρ = 0.47 is shown with magnetospheric proton detector protons for the 2 year period where both missions returned data uninterruptedly. This correlation proves that the SDO spike data can be proven useful for characterizing the Van Allen radiation belt, especially at areas where other satellites cannot.Plain Language SummaryThe Solar Dynamics Observatory (SDO) is a NASA mission that has been observing the Sun since 2010. One instrument aboard SDO is the Atmospheric Imaging Assembly (AIA) which acquires pictures of the Sun in seven extreme ultraviolet and two ultraviolet channels. The AIA detector is designed to capture solar photons of different wavelengths to create images. However, SDO is located in a geosynchronous orbit, which passes through regions of the outer radiation belt. Energetic particles that impact the detector result in brightened pixels in the SDO images. An algorithm removes and records these unusual pixels in every AIA image. Although these pixels are considered noise, in this research we use them to infer the particle density along SDO’s orbit. This paper proves that the fluctuation of the number of noisy pixels in AIA’s images best matches the fluctuation of the electron readings from the nearby GOES-14 weather satellite. This research shows that these noisy pixels can be turned to a data product useful for characterizing the Van Allen radiation belt.Key PointsMore than 3 trillion “spiked pixels” attributed to magnetospheric particle impacts have been removed from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images so farThe SDO spike rate was compared to particle measurements from GOES-14 during close orbital conjunctions occurring twice daily over 27 monthsThe high correlation between AIA spikes and GOES-14 electron fluxes indicates that AIA spikes could be a proxy for radiation belt electron fluxesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/176078/1/swe21472.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176078/2/swe21472_am.pd

Helionauts: A Cross-Organization Heliophysics Forum

<p>The COVID-19 pandemic highlighted the need for a lasting community-wide discussion platform in the field of Heliophysics, supplementing in-person interactions at conferences and within local departments. To address this, instant messaging apps like Slack and Teams were hastily adopted, but their constant online presence requirements posed problems: overlapping content and information sprawl across various chat workspaces, confusion about where discussions should take place. To provide a more coherent landscape for written communication, NASA is backing Helionauts.org, a permanent platform for heliophysicists. It features topic-based and searchable discussions, smart notifications for asynchronous conversations, and supports technical conversations with Markdowns, LaTeX, and code syntax highlighting. The platform fosters inclusivity, connecting experts, postdocs, and students to promote knowledge-sharing and collaboration in our heliophysics community. </p&gt