Solar Eclipse Research Articles (Page 1)

A total solar eclipse covered much of the USA in 2024. Ahead of the eclipse, the University of Arkansas at Little Rock began preparing to host an event for the campus and community to watch this phenomenon. During the planning process, Marketing and Communications (MarComm) recognised the potential to use the eclipse to secure national media placement for the university. By employing five key strategies of taking a unique approach, preparing media experts, using the website early, incorporating video and dreaming big, the MarComm team garnered more than 320 media mentions and 3.5 billion media impressions and secured multiple national placements. This article is also included in The Business & Management Collection which can be accessed at https://hstalks.com/business/.

Response of the ionosphere to the total solar eclipse in the United States on April 8, 2024

This study examines the impact of the 2024 Total Solar Eclipse on participants’ feelings of awe, science identity, and interest in science-related activities through structured science engagement events. Drawing on a mixed-methods approach, the research collected data from over 1,300 attendees at NASA-hosted eclipse events across the United States, with follow-up surveys conducted 6 months later. Findings reveal that the eclipse evoked high levels of awe, which remained relatively stable over time. Participants also reported elevated science identity and intentions to engage in future science activities; however, a gap was observed between intention and action. Correlational analyses suggest that awe, science identity, and science engagement are interrelated and mutually reinforcing. These results underscore the potential of awe-inspiring natural phenomena to serve as powerful catalysts for informal science learning and long-term public engagement with science.

This paper explores how ancient Mayan calendar specialists designed a predictive eclipse table, revising a century of interpretation. The table's length, 405 months, was originally implemented in a general lunar calendar table of 405 successive months; within a few passes through this lunar calendar, intervals among observed eclipses could have stimulated an approximation to the series of lunar intervals that were later compiled as stations of an eclipse table; and for all and only these lunar stations to correspond to dates of upcoming eclipses, dates in successive 405-month eclipse tables would have to have overlapped. It identifies optimal procedures for the amounts of overlap that would maintain its predictions' correctness and shows that these procedures could yield a sequence of tables that would anticipate every solar eclipse observable in the Mayan territory from a century or two after the first evidence of the Mayan lunar calendar to at least the era of the extant eclipse table, 700 years later.

Abstract Solar eclipse events (SEs) provide an excellent natural experiment for the response of the middle atmosphere to short‐term changes in solar radiation. For this study, we quantify radiation variations through obscuration, which is defined as the fraction of the solar disk obscured by the Moon during SEs. Using Aura Microwave Limb Sounder satellite observations, we analyze the changes in the average ozone mixing ratio at the upper stratosphere and the lower mesosphere during multiple SEs since July 2004. The results show that during SEs, ozone at the upper stratosphere and the lower mesosphere is sensitive to short‐term solar radiation changes and increases to about twice the normal daytime ozone mixing ratio. The ozone increase tends to level off with increasing obscuration during SEs, especially near the totality. We estimate that the effect of water vapor photolysis, the primary photochemical process of mesospheric ozone depletion, is greatly suppressed during SEs. Furthermore, we detect O 3 changes at 0.46 hPa, which cannot be explained solely by changes in temperature or solar radiation. However, CO observation, a long‐lived tracer, did not reveal any common characteristics in dynamical behavior related to O 3 changes near the stratopause.

The exchange of letters between Elias von Löwen and Johannes Hevelius, conducted in the years 1648–1654, contains an extensive thread devoted to solar eclipses. This article examines the attitudes of both astronomers towards the prevailing theories of lunar motion (necessary for calculating the course of eclipses) and towards the use of traditional (camera obscura, mechanical clock with the foliot) and innovative (telescope, pendulum) methods of conducting observations. The accuracy of the observations of solar eclipses from 1649 and 1652 described in the correspondence, made by Hevelius in Gdańsk, von Löwen in Byczyna, Albert Linemann in Königsberg and Pierre des Noyers in Warsaw, is also analyzed.

Non-uniform and Non-linear background correction methods for ionospheric TEC changes detection associated with solar eclipse

Abstract We report on a further analysis of the Airborne Infrared Spectrometer (AIR-Spec) observations from the 2019 July 2 total eclipse and present the identifications of three new coronal lines from Fe x, Si xi, and Si vi in AIR-Spec’s 1.87–1.99 μm band. The new lines were predicted to be observable but were not observed previously in the corona. The identifications are confirmed on the basis of observed and expected line wavelengths and radiances. The observed wavelengths are very accurate, as confirmed by neutral H and He lines measured during the same observation. The predicted wavelengths are assessed by reviewing previous experimental data used to estimate the energies of these ions. We find discrepancies with several previous measurements. A reanalysis of Solar Ultraviolet Measurement of Emitted Radiation data corrects previous measurements and provides excellent agreement with the AIR-Spec values for Si xi. AIR-Spec was developed to survey the near-infrared (NIR) coronal spectrum from above Earth’s atmosphere, a critical first step in designing future balloonborne and spaceborne instrumentation to observe coronal plasma and magnetic fields using NIR emission lines. The reported results are also of interest for ground-based observatories, as the precise measurements of line wavelength enable observers to understand the nearby telluric spectrum and determine which lines can be used from the ground.

On 8 April 2024, a total solar eclipse disrupted light-dark cycles for North American birds during the lead-up to spring reproduction. Compiling more than 10,000 community observations and artificial intelligence analyses of nearly 100,000 vocalizations, we found that bird behavior was substantially affected by these few minutes of unexpected afternoon darkness. More than half of wild bird species changed their biological rhythms, with many producing a dawn chorus in the aftermath of the eclipse. This natural experiment underscores the power of light in structuring animal behavior: Even when "night" lasts for just 4 minutes, robust behavioral changes ensue.

Abstract The corona is a crucial region that connects the solar surface to the solar wind and serves as the primary site of solar activity. The 2024 total solar eclipse (TSE) provides a unique opportunity to investigate the large-scale coronal structure. Combined with TSE observations, we study the impact of the magnetic structure of the farside active region, located in the eastern hemisphere of the Sun that has not yet rotated into the Earth field of view, on a global magnetohydrodynamic simulation. To address the limitation of single-view measurements for the routine synoptic map, we correct the magnetic field in the farside region by incorporating full-disk magnetograms measured several days after the TSE, allowing us to capture the temporal evolution of the photospheric magnetic field in near real time. Simulation results demonstrate that the local magnetic field in the farside active region can significantly influence the global coronal structure, by altering the position of the heliospheric current sheet, and further affect the global distribution of plasma parameters, even in polar regions. A comparison of the simulation results with white-light TSE + Large Angle and Spectrometric Coronagraph C2 observations and in situ measurements by the Parker Solar Probe reveals that the composite synoptic map improves the accuracy of the coronal modeling. This work provides robust support for advancing our understanding of coronal evolution, as well as deepening the link between the photosphere and large-scale coronal structure. Furthermore, it establishes a theoretical foundation for the future development of multiview stereoscopic measurements of the photospheric magnetic field.

An Interesting Shadow Observed during a Solar Eclipse

The total eclipse in 2026 is visible from Greenland, Iceland and Spain; in the British Isles, a large partial eclipse may be seen during the early evening. This paper summarises the circumstances of the eclipse in the British Isles, Iceland and across the Iberian Peninsula.

Studies of Salicylic Acid and Chitosan on Storage Ability of “Solar Eclipse” Plum Fruits

Solar eclipses induce abrupt reductions in solar radiation, triggering notable changes in the atmospheric boundary layer (ABL). This study employs large eddy simulations (LES) to investigate eclipse-induced ABL modulations over Thiruvananthapuram during the annular solar eclipse of 15 January 2010. Unlike previous studies that primarily relied on observational analyses, this work provides a first-of-its-kind numerical simulation of such phenomena using a state-of-the-art LES framework. The results reveal substantial impacts on ABL processes, including reduced solar irradiance, cooling of air and soil temperatures, and diminished turbulence intensity. These changes resulted in suppressed convection, a lowered ABL height, and weakened vertical mixing of heat and momentum. Furthermore, the suppression of turbulence, evidenced by reductions in eddy diffusivity coefficients for heat and momentum, restricted the vertical growth of the ABL and delayed its post-eclipse recovery. This investigation underscores the significant role of solar eclipses in modulating ABL dynamics and offers new insights into the atmospheric response to transient radiative forcing.

The 8 April 2024, total solar eclipse presented a unique opportunity to study ionospheric and magnetospheric responses to local changes in the solar illumination. As part of NASA’s citizen science initiative, we launched the EZIE-Mag Eclipse Measurement Campaign and deployed ultra low-cost, science-grade magnetometer kits operated by trained citizen scientists across diverse geographic locations. This grassroots decentralized approach enabled the collection of high-quality, distributed geomagnetic data. Observations from Muncie, Indiana, revealed a clear signal that is interpreted as being produced by eclipse-induced current system perturbations. This is an excellent example of complex electrodynamic coupling between the Sun and the magnetosphere-ionosphere-atmosphere environment. The results not only contribute to advancing Heliophysics research but also demonstrate the value of citizen science in enhancing space weather awareness and public education. The campaign’s inclusive approach in engaging participants from various backgrounds, underscores the potential for scalable, community-driven efforts to broaden participation and deepen public understanding of space weather phenomena.

Abstract We present an analysis of solar wind dynamics based on Doppler spectral width measurements of X-band radio signals from the Japanese Akatsuki spacecraft. The dataset includes two solar conjunction occultation experiments conducted in 2016 and 2022, capturing the transition from the descending phase of Solar Cycle 24, a period of low solar activity, to the ascending phase of Solar Cycle 25, which exhibited moderate to intense activity. Our study demonstrates the utility of this technique for estimating both slow and fast solar wind velocities across different phases of solar activity. A key focus is the 2022 experiment, which probed the solar corona near coronal holes at heliocentric distances ranging from 1.4 to 10 R⊙. We also investigate the impact of electron density estimates on the accuracy of solar wind speed determinations, underscoring the need for improved electron density modeling to enhance the robustness of such measurements.

The article is focused on the quantitative assessment of the thermal impact of polar mesospheric clouds (PMCs) on the mesopause caused by the emission of absorbed solar and terrestrial infrared (IR) radiation by cloud particles. For this purpose, a parameterization of mesopause heating by PMC crystals has been developed, the main feature of which is to incorporate the thermal properties of ice and the interaction of cloud particles with the environment. Parametrization is based on PMCs zero-dimensional (0-D) model and uses temperature, pressure, and water vapor data in the 80–90 km altitude range retrieved from Solar Occultation for Ice Experiment (SOFIE) measurements. The calculations are made for 14 PMC seasons in both hemispheres with the summer solstice as the central date. The obtained results show that PMCs can make a significant contribution to the heat balance of the upper atmosphere, comparable to the heating caused, for example, by the dissipation of atmospheric gravity waves (GWs). The interhemispheric differences in heating are manifested mainly in the altitude structure: in the Southern Hemisphere (SH), the area of maximum heating values is 1–2 km higher than in the Northern Hemisphere (NH), while quantitatively they are of the same order. The most intensive heating is observed at the lower boundary of the minimum temperature layer (below 150 K) and gradually weakens with altitude. The NH heating median value is 5.86 K/day, while in the SH it is 5.24 K/day. The lowest values of heating are located above the maximum of cloud ice concentration in both hemispheres. The calculated heating rates are also examined in the context of the various factors of temperature variation in the observed atmospheric layers. It is shown in particular that the thermal impact of PMC is commensurate with the influence of dissipating gravity waves at heights of the mesosphere and lower thermosphere (MLT), which parameterizations are included in all modern numerical models of atmospheric circulation. Hence, the developed parameterization can be used in global atmospheric circulation models for further study of the peculiarities of the thermodynamic regime of the MLT.

Rapid industrialization and urbanization have progressed in Korea, yet public attention to hazardous pollutants emitted from industrial complexes remains limited. With the increasing coexistence of industrial and residential areas, there is a growing need for real-time monitoring and management plans that account for the rapid dispersion of hazardous air pollutants (HAPs). In this study, we conducted spatiotemporal data collection and analysis for the first time in Korea using real-time measurements obtained through mobile extractive differential optical absorption spectroscopy (Me-DOAS) mounted on a solar occultation flux (SOF) vehicle. The measurements were conducted in the Saha Sinpyeong–Janglim Industrial Complex in Busan, which comprises the Sasang Industrial Complex and the Sinpyeong–Janglim Industrial Complex. BTEX compounds were selected as target volatile organic compounds (VOCs), and real-time measurements of both BTEX and fine particulate matter (PM) were conducted simultaneously. Correlation analysis revealed a strong relationship between PM10 and PM2.5 (r = 0.848–0.894), indicating shared sources. In Sasang, BTEX levels were associated with traffic and localized facilities, while in Saha Sinpyeong–Janglim, the concentrations were more influenced by industrial zoning and wind patterns. Notably, inter-compound correlations such as benzene–m-xylene and p-xylene–toluene suggested possible co-emission sources. This study proposes a GIS-based, three-dimensional air quality management approach that integrates variables such as traffic volume, wind direction, and speed through real-time measurements. The findings are expected to inform effective pollution control strategies and future environmental management plans for industrial complexes.

Abstract This study investigates thermospheric response to the 2019 solar eclipse, focusing on temperature and neutral mass density variations at Wuhan and Beijing. The method proposed by Li et al. (2023, https://doi.org/10.1029/2022ja030988) to derive thermospheric parameters from electron density profiles was employed. Results revealed a significant temperature decrease at both locations. At Wuhan, the exospheric temperature (Tex) dropped by up to 50 K, with maximum decrease occurring approximately 45 min after peak obscuration. Similarly, at Beijing, Tex decreased by a maximum of 30 K, also peaking around 45 min after maximum obscuration. Using an energy balance model, the estimated Tex reduction explained the time lag between maximum obscuration and minimum Tex. Changes in neutral mass density exhibited altitude dependence, but followed a similar temporal trend to temperature changes. These findings highlight the significant impact of solar eclipses on the thermosphere and emphasize the importance of considering various influencing factors in future research.

Abstract We analyzed Hubble Space Telescope observations of Europa’s optical aurora, yielding further insight into the composition of its tenuous atmosphere and its plasma-interaction variability. We obtained these observations of auroral emissions while Europa was in solar eclipse behind Jupiter to avoid reflected sunlight as a background signal and source of noise. We analyzed oxygen 630.0 and 636.4 nm emission line brightness profiles across the disk to constrain O2 abundances. Analyses of time-varying brightness ratios across different regions of Europa were compared with previous auroral studies in the ultraviolet and in the visible. We confirm a correlation with auroral brightness and relative distance from Jupiter’s plasma sheet crossing. We find that the decorrelated set of auroral brightnesses diminishes with longer eclipse duration, suggesting a possible partial collapse of Europa’s atmosphere when in eclipse.