In Fujisawa et al. (2022) [1], we previously produced an objective analysis of the Venusian atmosphere by assimilating horizontal winds derived from cloud tracking of the UVI camera onboard the Venus orbiter Akatsuki. To produce objective analysis, we used the Venus atmospheric data assimilation system ALEDAS-V (Sugimoto et al., 2017) [2], which is based on the Venus general circulation model AFES-Venus (Sugimoto et al., 2014) [3]. This dataset appropriately corrects both the phase bias of thermal tides and the super-rotation speed in AFES-Venus to be closer to those observed in the real Venusian atmosphere. The dataset was produced by assimilating observations from September to December 2018, a period that includes an intensive observation period of Akatsuki.

Akatsuki has accumulated observational data over a long period from 2015 to 2024, and it has been revealed that the super-rotation speed exhibits both faster and slower periods (Horinouchi et al., 2024) [4]. In this study, we selected five epochs during the Akatsuki observation period that exhibit characteristic super-rotation speeds and performed data assimilation for each epoch. As a result, we confirmed that distinct super-rotation speeds corresponding to each epoch, including their meridional asymmetry, are reproduced. In the presentation, we will show the relationship between the reproduced super-rotation speeds and the structure of the atmospheric circulation.

• [1] Fujisawa, Y., et al. (2022) Sci. Rep. 12, 14577.
• [2] Sugimoto, N., et al. (2017) Sci. Rep. 7(1), 9321.
• [3] Sugimoto, N., et al. (2014) J. Geophys. Res. Planets 119, 1950–1968.
• [4] Horinouchi, T., et al. (2024) J. Geophys. Res. Planets 129, e2023JE008221.

How to cite: Fujisawa, Y., Sugimoto, N., Komori, N., Murakami, S., Ando, H., Takagi, M., Imamura, T., Horinouchi, T., Hashimoto, G. L., Ishiwatari, M., Enomoto, T., Miyoshi, T., Kashimura, H., and Hayashi, Y.-Y.: Reproduction of Long-Term Variability of Super-Rotation Using Akatsuki Horizontal Wind Data Assimilation, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3726, https://doi.org/10.5194/egusphere-egu26-3726, 2026.

Terrestrial exploration with the help of rovers typically employs traditional stereo cameras, relying on binocular optical designs with large, bulky, and often moving parts. The stereo camera design concept presented in this study was developed and built using commercial off-the-shelf (COTS) components, allowing for rapid-prototyping, cost-effective testing, and performance evaluation under simulated mission conditions. An innovative use of four-mirror optical configuration and a monochrome CMOS sensor introduces a novel approach to achieve high resolution stereo imaging, while maintaining low power consumption and space requirements suitable for compact lander missions. By utilizing a single-detector stereo vision, the camera system can effectively create 3D reconstructions of observed objects with a spatial resolution of 54 μm per pixel, and depth resolution of <1 mm per pixel with the stereo baseline length of 116 mm, an instantaneous field of view of 601 μrad per pixel. The optical performance was validated with experiments such as the resolution and shape measurement test. The scientific applicability was demonstrated by extracting the static angle of repose of regolith simulants EAC-1A and NU-LHT-2M, as well as the relative surface albedo through a photometric stereo method, providing deeper understanding into the physical and optical properties of lunar regolith analogues. The presented camera design offers a balance between performance with compactness, addressing challenges faced by conventional stereo cameras such as baseline constraints, environmental exposure, and computational efficiency. Further design limitations and stereo matching inaccuracies were identified during testing and characterisation. The stereo camera developed in this study demonstrates capabilities for high-resolution, in-situ lunar surface analysis based on regolith characterization and contributes to an in-depth understanding of lunar regolith properties by close-range scientific analysis of its geo-mechanical behaviour.

How to cite: Chauhan, S. C., Jaumann, R., Grott, M., and Althaus, C.: Prototype Design for a Lunar Lander High Resolution Stereo Camera, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7948, https://doi.org/10.5194/egusphere-egu26-7948, 2026.

Auroras are the result of charged particles interacting with a planetary atmosphere, driving several processes involving the excitation and ionization of molecules and atoms, leading to spectacular emissions. This study investigates Martian auroral emissions using observations from the Emirates Ultraviolet Spectrometer (EMUS) onboard the Emirates Mars Mission (EMM) Hope Probe. The analysis focuses on the oxygen emission lines at 130.4 nm and 135.6 nm, which are key diagnostics of electron precipitation. EMUS emission images are processed to compute brightness maps and intensity ratios, identify energetic regions using thresholding techniques, and generate histograms that characterize the spatial distribution and statistical properties of auroral energy across different regions of Mars.

In addition, data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission, particularly magnetic field measurements from the MAG instrument, are used to correlate auroral observations with the Martian crustal magnetic field. By combining EMM ultraviolet observations with MAVEN magnetic field measurements, the study explores the relationship between auroral morphology, energy deposition, and underlying magnetic field topology.The goal is to assess how magnetic field geometry influences the localization and structure of auroral emissions and to better constrain the coupling between the solar wind, the Martian magnetosphere, and the upper atmosphere.

The combined analysis demonstates the potential of how combined EMM and MAVEN observations improves our understaing of of auroral processes on Mars and their implications for planetary atmosphere studies and space weather interactions.

How to cite: Alblooki, S. and Atri, D.: Exploring Martian Auroras Using EMM/EMUS and MAVEN/MAG: Insights into Ultraviolet Emissions and Crustal Magnetic Field Interactions, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8953, https://doi.org/10.5194/egusphere-egu26-8953, 2026.

The recent Martian exploration mission has provided substantial evidence for the presence of hydrous sulphate minerals, especially in the Gale Crater and Meridiani Planum. These findings are crucial for understanding the past climate, water activity, and geological history of early Mars. Studying the sulphate formation process, particularly jarosite, has become increasingly important. In this context, terrestrial analog sites with similar mineral deposits can serve as effective models for exploring and analyzing sulphate deposits in detail. The Matanomadh and Harudi formations of Kachchh, Gujarat, India, were chosen as Martian analog sites because they expose well-preserved, clay-rich jarosite layers that may help better understand paleo-environmental conditions during Martian alteration. Here, jarosite is found alongside grey carbonaceous shale, weathered basalt, and gypsum, typically appearing as lenses of variable width, interconnected veins, or veinlets. Pure jarosite samples were collected after detailed field studies from the Matanomadh and Harudi formations of Kachchh. Powdered samples were characterized using X-Ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HR-TEM), Field Emission Scanning Electron Microscopy (FE-SEM), X-Ray Photoelectron Spectroscopy (XPS), and Elemental Analyzer-Isotope Ratio Mass Spectrometry (EA-IRMS) for sulfur isotope analysis. All XRD patterns were analyzed with the FullProf program using Rietveld refinement, employing the R-3m space group. The average a- and c-cell dimensions for jarosite were calculated as a = 7.3028 Å and c = 16.6376 Å. The XRD diffractogram displays a distinct peak at (006) at 2θ = 32.29°. FE-SEM images show that jarosite crystals have well-formed pseudohexagonal shapes with defined faces and edges. HR-TEM analysis indicates the dominance of sodium (Na), and elemental mapping confirms homogeneous grains. XPS analysis of jarosite revealed prominent peaks for Fe2p_3/2 and S2p at approximately 713.4 eV and 169.9 eV, respectively. S2p peaks were also observed in the host shale rock. δ³⁴S values for jarosite (-8.4 to -16‰) are close to values typical of supergene or steam-heated hydrous sulphates derived from pyrite or H₂S oxidation. The cell dimensions obtained from XRD data agree with literature values, confirming the mineral as Natrojarosite. The peak position of the (006) reflection in natrojarosite differs from that of jarosite. In this sample group, iron (Fe) exists in the +3 oxidation state, as confirmed by XPS. Based on the presence of sulfur (S -1) peaks in the associated shale, it is inferred that shale may serve as a sulfur source for natrojarosite formation in the current study area under acidic, oxidizing conditions.

How to cite: Saha, N. and Majumdar, A. S.: Integrated Micro to Nano-Scale Characterization of Hydrous Sulphate Mineral-Jarosite in Kachchh, Gujarat, India: Implication for Mars, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-12992, https://doi.org/10.5194/egusphere-egu26-12992, 2026.

The radical terraforming of Mars was proposed in 2025 (LPSC2025, 1558.pdf) envisions bringing volatiles with a total mass of approximately 10¹⁹ kg from the Kuiper Belt to Mars. This would amount to approximately 1000 asteroids. Upon reaching Mars, these bodies will have velocities ranging from a few to a dozen or so km/s relative to the planet. The impact sites and their parameters will be controlled to some extent. This would be a unique opportunity to use these bodies to modify the surface of Mars. The goal of radical terraforming is also to create open water reservoirs and rivers. The planet's current topography makes these plans very difficult. Large elevation differences would lead to rapid concentration of water in a few low-lying areas. We show examples of possible stable zones that would provide habitable conditions for ecosystems from Earth. Another possibility of using impacts is the targeted transformation of minerals. Asteroids themselves contain not only water and volatile substances but also other compounds. Placing them in appropriate places can make the economy easier for future residents.

How to cite: Czechowski, L.: Radical Terraforming of Mars and Planetary Engineering, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14494, https://doi.org/10.5194/egusphere-egu26-14494, 2026.

Jupiter’s moon Io is the most volcanically active body in the Solar System, powered by intense internal heating due to tidal dissipation. Although tidal friction is widely accepted as the main energy source, how this heat is distributed within Io and how it shapes the moon’s internal structure remain open questions. In this study, we use Io’s tidal response, quantified through the degree-2 Love number (k₂)_, to constrain its interior, using recent estimates derived from Juno observations (Park et al., 2025).

We model Io with a three-layer structure consisting of a fluid core, a viscoelastic mantle, and a crust, using an adapted version of the California Planetary Geophysics Code (CPGC). Tidal dissipation is self-consistently coupled to mantle rheology through an Andrade model, with viscosity and shear modulus updated as functions of the local melt fraction. We explore two end-member scenarios that differ in the treatment of the Andrade parameter β: in the first, β is held constant, representing a uniform dissipation regime dominated by deep-mantle heating; in the second, β varies with depth, allowing dissipation to be preferentially localized in the upper mantle. In both scenarios, viscosity and shear modulus evolve with melt fraction.

Our results identify several partially molten mantle configurations whose real part of k₂ is consistent with Juno constraints. In all acceptable models, melt fractions remain below the threshold required to form a global magma layer. To test the physical viability of these states, we compare thermodynamic melt production with the capacity for melt migration. We find that melt transport is efficient enough to prevent long-term melt accumulation, favoring a stable, partially molten “magma sponge” rather than a global magma ocean. These results provide new constraints on Io’s thermal state and are consistent with independent estimates of its global volcanic output.

How to cite: Paris, M., Mura, A., Zambon, F., Genova, A., Tosi, F., Piccioni, G., Consorzi, A., Mitri, G., Sordini, R., Noschese, R., Cicchetti, A., Plainaki, C., Bolton, S., and Sindoni, G.: Juno Constraints on Io’s Interior: Tidal Response and Melt Stability, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-5870, https://doi.org/10.5194/egusphere-egu26-5870, 2026.

The Juno spacecraft made close flybys of Io on Dec. 2023 (PJ57) and Feb 2024 (PJ58) above respectively the northern/southern hemisphere with an altitude at closest approach (CA) of ~1,500 km.

On PJ57, Juno went through the Alfven wing and both the Juno/Waves and Radio-occultation measurements showed a surprising large electron density n_el ~ 28,000 near closest approach. On PJ58, Juno flew slightly behind the Alfven wing and the instruments measured a plasma density consistent with the background plasma torus density.

We run numerical simulations of the plasma/atmosphere interaction along teh PJ57 and PJ58 flyby to constrain IO’s polar atmosphere. Our numerical simulations are based on (1) A prescribed atmospheric composition and distribution of S, O, SO₂ and SO; (2) A MHD code to calculate the plasma flow into Io’s atmosphere; (3) A multi-species physical chemistry code to compute the change of the plasma properties (ion densities, composition and temperature) during the plasma/atmosphere interaction (4) a formulation of the ionization by the field-aligned electron beams used for auroral electrons on Earth.

We compute the multi-charged ion composition of the plasma along each flyby and compare to the Juno/JADE measurements to infer the atmosphere composition (O, S, SO2, SO) and density at polar latitudes. 

How to cite: Dols, V. and Bagenal, F.: The Juno PJ57 and PJ58 flybys of Io: Multi-species physical chemistry simulations , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-14914, https://doi.org/10.5194/egusphere-egu26-14914, 2026.

Jupiter’s magnetosphere features internal mass loading from its innermost moon Io. The neutral gases from Io’s escaping atmosphere are ionized to become the plasma torus, which mainly consists of sulfur and oxygen ions. Under centrifugal force, plasma in the torus is transported outward and forms a thin plasma disk near the equator, while the transport mechanism and timescale remain unclear. Since 2016, the plasma disk between 10 and 50 RJ has been continuously observed by the Juno mission. Using multi-year thermal plasma measurements from the JADE ion detector, we perform an analysis that reveals significant temporal variation of plasma disk from a long-term perspective. For different Juno orbits, the plasma disk observations are categorized as either enhanced or depleted based on plasma density. Extreme cases indicate vastly different states of the plasma disk, with variations exceeding one order of magnitude. Further analysis of multiple plasma disk crossings by Juno reveals correlations between density enhancements and fluctuations in plasma density and magnetic field profiles, which are typical features of flux tube interchange. This suggests that flux tube interchange is triggered by an increase in the plasma source and is considered the primary mechanism for outward plasma transport. Finally, Juno’s in-situ measurements also show a correlation with remotely sensed Io’s torus ribbon brightness from the ground-based IoIO observatory, lagged by about 30 to 50 days. This suggests that the temporal variation of the plasma disk is modulated by changes in Io’s torus and that the average plasma transport time from the torus to the plasma disk is around 40 days. 

How to cite: Bagenal, F. and Wang, J.-Z.: Temporal Variations of Jupiter’s Plasma Disk Observed by Juno , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4537, https://doi.org/10.5194/egusphere-egu26-4537, 2026.

This contribution presents a petrographic, microstructural, and micro-analytical approach developed for the comprehensive study of ordinary chondrites, as part of a master’s thesis aimed at defining an analytical protocol for the petrological and minerochemical characterization of extraterrestrial materials. The ultimate goal is the establishment of a dedicated laboratory for the petrological study of meteorites, exploiting available instrumentation and acquired micro-analytical expertise to achieve both a complete classification of chondrites and a deeper understanding of the processes governing their genesis and evolution.

The study was carried out in collaboration with the Italian Museum of Planetary Sciences, where an internship allowed the examination of a reference collection of classified meteorite thin sections commonly used for educational purposes. Subsequently, three ordinary unclassified chondrites, provided by the “Museo del Cielo e della Terra” (San Giovanni in Persiceto, Bologna, Italy) and by a private collection, were investigated.

The analytical workflow includes: (i) macroscopic measurements and photographic documentation; (ii) petrographic analysis by transmitted and reflected light optical microscopy for microstructural and mineralogical characterization; (iii) SEM-EDS X-ray compositional mapping on the whole petrographic thin section as well as on selected chondrules and microstructural sites; (iv) SEM-EDS quantitative microanalyses of mineral phases; and (v) micro-Raman spectroscopy.

Preliminary results indicate that, from a chemical perspective, two of the unclassified samples can be assigned to the H group and one to the L group of ordinary chondrites. Petrographic observations classify the investigated meteorites as petrologic types 4 to 6. The most common chondrule textures observed include porphyritic and barred olivine, porphyritic olivine–pyroxene, granular olivine–pyroxene, radial pyroxene, and complex chondrules.

SEM-EDS compositional maps of entire thin sections and selected microstructural domains enable visualization of textural relationships, estimation of modal mineral abundances relative to metallic phases, and the development of a comparative framework among ordinary chondrites. Mineral chemistry data are compared with literature values to refine classification criteria. Micro-Raman spectroscopy is performed on opaque phases or on selected minerals for the correct identification of the polymorphic phase which constrains proper ranges of P-T conditions. Moreover, micro-Raman analyses are employed to characterize solid and fluid/melt inclusions within primary minerals, assess surface alteration features, and investigate dust extracted from fractures, providing insights into secondary processes related to atmospheric entry and post-impact evolution.

How to cite: Borghetti, S., Di Martino, M., Ferrando, S., Faggi, D., Ghignone, S., Morelli, M., Serra, R., and Vaggelli, G.: A Petrographic and Micro-Analytical Framework for the Study and Classification of Meteorites, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11477, https://doi.org/10.5194/egusphere-egu26-11477, 2026.

Organic compounds are a ubiquitous component of cosmic dust and provide insight into the origin of planetary systems, the availability of carbon for life in the solar system and beyond, and the distribution of potential biosignatures in the universe. Compositional and dynamical analysis of such dust grains can shed insight into their origin. The Destiny Dust Analyzer (DDA) onboard JAXA’s interplanetary space mission DESTINY+ will detect and analyse the composition of (sub-)micron sized dust ejecta during flybys of asteroids Apophis and Phaethon [1,2]. DDA will characterise both interplanetary and interstellar dust grains during the mission’s lifetime [3]. DDA is an impact ionisation time-of-flight mass spectrometer, whereby dust particles incident onto the instrument’s target at hypervelocity (≥ 2 km s^-1) vaporise and partially fragment into various constituent ions and neutrals. Here, we investigate the capability of DDA to detect a mixture of complex organic compounds in single cosmic dust particles. An organic cosmic dust analogue is prepared by coating polycyclic aromatic hydrocarbon, perylene (C₂₀H₁₂), microparticles with an ultrathin overlayer of a conductive polymer, polypyrrole H(C₄H₂NH)_nH, to enable acceleration up to hypervelocities with a high-voltage van de Graaff instrument. Time-of-flight mass spectra obtained at impact speeds ~3-20 km/s are recorded in this calibration campaign. The characteristic parent molecular ion for perylene, [C₂₀H₁₂ (+H)]⁺, is observed at m/z 251 ± 1 in mass spectra arising from impacts between 3 and 8 km s^-1. However, between 8 and 18 km s^-1, no such parent ion is observed. Instead, impact ionisation mass spectra exhibit a characteristic series of homologous [C_nH_m]⁺ fragments originating from both polypyrrole and perylene, alongside some non-sequential ions which may be diagnostic for distinguishing between different organic components in cosmic dust. The contributions of each species to fragmentation patterns in the mass spectra is coupled with the impact velocity. Our results are in agreement with Mikula et al. (2024), who investigated impact ionisation of polypyyrole-coated anthracene particles for the Interstellar Dust EXperiment (IDEX) onboard NASA's Interstellar Mapping and Acceleration Probe (IMAP), and observed a similar relationship between fragmentation pattern and velocity [4].

Additional experiments with a range of PAHs, heterocycles, and lower mass organics at various velocities, will yield further insight into the detection and characterisation of heterogeneous dust likely to be encountered by DDA. Similarly, theoretical chemical calculations could assist in deciphering the contribution of different species to mass spectral features via the analysis of dissociation thermodynamics and kinetics.

[1] Ozaki et al. (2022) https://doi.org/10.1016/j.actaastro.2022.03.029

[2] Simolka et al. (2024) https://doi.org/10.1098/rsta.2023.0199

[3] Krüger et al. (2024) https://doi.org/10.1016/j.pss.2024.106010

[4] Mikula et al. (2024) https://doi.org/10.1021/acsearthspacechem.3c00353

How to cite: Khawaja, N., Srama, R., Chan, D. H. H., Simolka, J., Armes, S. P., Mikula, R., Hirai, T., Li, Y., Strack, H., O'Sullivan, T. R., Bera, P. P., Mocker, A., Trieloff, M., Postberg, F., Hillier, J. K., Kempf, S., Sternovsky, Z., Yabuta, H., and Krüger, H.: Deciphering mixtures of complex organic compounds in cosmic dust particles using JAXA's Destiny+ Dust Analyzer, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-21015, https://doi.org/10.5194/egusphere-egu26-21015, 2026.

Multi-ring impact basins represent some of the oldest and most degraded large-scale structures on terrestrial planetary bodies, making their identification and characterization particularly challenging. Only a few well-preserved examples are known, such as the Orientale basin on the Moon, commonly regarded as the archetype of multi-ring basins. On Mercury, several multi-ring basins were initially proposed based on Mariner 10 imagery (Spudis & Guest, 1988); however, most of these candidates were not confirmed by subsequent analyses using MESSENGER data (e.g., Fassett et al., 2012; Orgel et al., 2020), highlighting the difficulty of recognizing ancient, highly modified basin architectures. Here we present a semi-automatic workflow aimed at the systematic characterization of multi-ring basins on Mercury. The workflow combines manual structural mapping with quantitative, data-driven analyses and consists of four main steps: (1) construction of a structural map of tectonic features; (2) determination of the basin center using concentric deviation analysis (Karagoz et al., 2024); (3) estimation of the multi-ring geometry through a newly developed tool that analyzes the radial distribution of mapped structures using one-dimensional kernel density estimation (KDE). In this step, dominant concentric rings are identified as statistically robust density maxima obtained with a Gaussian kernel and an objectively defined Silverman bandwidth, while ring uncertainty is quantified through the interquartile range (IQR) of associated structures; and (4) comparison of the inferred ring geometry with the basin’s median radial topographic profile, derived from 360 azimuthally distributed radial profiles, to assess geometric and morphological consistency. We apply this workflow to two basins of different confidence levels. For the Orientale basin on the Moon, the method identifies three concentric rings corresponding to the Inner Rook Ring, Outer Rook Ring, and Cordillera Ring, consistent with previous studies (Spudis et al., 2013). For the Andal–Coleridge basin on Mercury, a probable multi-ring basin, the workflow retrieves a four-ring geometry that broadly coincides with rings II–V proposed by Spudis & Guest (1988). These results demonstrate that the combined use of structural mapping, KDE-based ring detection, and radial profile analysis provides a robust and reproducible framework for investigating degraded multi-ring basins. Future work will apply this workflow to additional candidate basins on Mercury to reassess their multi-ring nature and improve constraints on the planet’s early impact and tectonic history.

Acknowledgements: We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2024-18-HH.0.

How to cite: Sepe, A., Ferranti, L., Galluzzi, V., Schmidt, G. W., and Palumbo, P.: A data-driven approach to multi-ring basin identification on Mercury, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-23072, https://doi.org/10.5194/egusphere-egu26-23072, 2026.

The influence of dissipating solar diurnal tides in driving the mean zonal wind in the upper mesosphere and lower thermosphere (UMLT) is investigated using the zonal and meridional winds observed by the Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI) instrument onboard the Ionospheric Connection Explorer (ICON) satellite over the region of interest having a latitudinal and longitudinal extent of 5° N - 15°N and 67.5°E - 90°E, respectively, for the years 2020, 2021 and 2022. The mean zonal wind exhibits consistent seasonal variation with large westward winds at 91-103 km during January-March and September-December, however with varying intensity (20-40 m/s) in all the three years. The diurnal tidal amplitude in meridional wind (DTV) also displays similar seasonal variation with maximum amplitudes reaching ~80–100 m/s. The seasonal variation of westward acceleration due to diurnal tide momentum deposition is found to be maximum during January-March (18-43 m/s/day) and September-December (40-55 m/s/day) and reveals similar seasonal variation and intensity of the mean westward winds. This clearly indicates that the potential role of diurnal tide in driving the mean zonal flow.  The westward acceleration induced by the vertical gradient of meridional flux of zonal momentum (F_meridional) due to diurnal tide exceeds the convergence of vertical flux of zonal momentum (F_zonal) due to diurnal tide during January-March, while the westward acceleration induced by both F_zonal and F_meridional are larger and comparable during September-December.

How to cite: Basu, S. and Sundararajan, Dr. S.: Influence of diurnal tide on the low-latitude UMLT mean zonal wind: Evidence from momentum flux estimation using ICON-MIGHTI winds, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2435, https://doi.org/10.5194/egusphere-egu26-2435, 2026.

We performed a one-year long simulation using the upper-atmosphere configuration of the Icosahedral Nonhydrostatic model (UA-ICON). The simulation has a horizontal resolution of 20 km and 180 vertical levels between the ground and 150 km. At 110 km height and every hour we extracted the gravity wave vectors and amplitudes with the small-volume few-wave decomposition method S3D, which is part of the software package JUWAVE. We focus on low-latitudes, i.e. +/- 40 degrees. The model simulates clear signatures of gravity wave activity above convective hotspots over summer continents. Ray tracing shows that the largest perturbations in the thermosphere are likely primary waves from developing convection. These signatures are most prominent in waves with short horizontal scales and long vertical wavelengths. In turn, horizontally short waves with smaller vertical wavelengths cannot be traced down to the lower stratosphere. For horizontally long waves, we find a clear diurnal/longitudinal pattern in the gravity wave activity, which results from interactions with tides. The study has broad implications of how whole-atmosphere high-resolution models may help forecast thermospheric density and ionospheric perturbations, both from the numerical weather prediction perspective, as well as empirically based on known patterns of lower-atmospheric variability.

How to cite: Stephan, C.: Tracing low-latitude thermospheric gravity waves in a whole-atmosphere simulation to their sources, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-2620, https://doi.org/10.5194/egusphere-egu26-2620, 2026.

Participatory science, also called citizen science, connects scientists with the public to enable discovery by engaging broad audiences across the world. In aurora science, direct collaborations, crowdsourced efforts, and community engagement bridge aurora chasers with scientists to do research. These efforts have been fueled by recent large geomagnetic storms, evolving consumer camera technologies, social media, and dedicated citizen science projects. In this presentation, we highlight recent, cutting-edge participatory science efforts with a primary focus on the Aurorasaurus project and how it can be used to study major storm-time auroral activity.

Aurorasaurus is an award-winning citizen science platform that has been operating for over a decade. Aurora observers submit visibility reports and photos, which are filtered and cleaned to generate science-quality datasets. We highlight Aurorasaurus data from recent major geomagnetic storms in 2024 and 2025, emphasizing how rapid, widespread reporting during extreme events enables mapping of storm-time auroral extent and tracking changes in the auroral oval boundary at low latitudes. During the May 10-11, 2024 geomagnetic storm, Aurorasaurus compiled more than 5,000 vetted reports from 50+ countries, allowing for unique data-model comparisons and tracking of the extent of auroral visibility.

We also address the efficacy of using citizen science photos for research. We discuss how submitted images not only provide additional perspectives and validation of reported auroral forms, but can also constitute unique scientific datasets beyond the capabilities of traditional instrument networks. For example, modern consumer cameras can capture high spatial resolution views of fine-scale auroral structure, and photos from multiple observers can be combined to enable stereoscopic and tomographic reconstructions of auroral morphology and its evolution.

Finally, we briefly note complementary campaign-style participatory science efforts, including the AurorEye project’s low-cost deployable all-sky timelapse units, the SolarMaX mission in coordination with SpaceX’s Fram2 launch, and collaborations between aurora chasers and the SuperDARN team to supplement radar measurements with optical aurora data. With the ongoing solar maximum, it is important to harness the excitement and enthusiasm surrounding the aurora and space weather. Participatory science efforts build important relationships between public communities and scientists and unlock unique research benefits.

How to cite: Ledvina, V., MacDonald, E., Edson, L., and Natsheh, F.: Cutting-Edge Projects in Aurora Participatory Science, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-16003, https://doi.org/10.5194/egusphere-egu26-16003, 2026.

Prior studies identified a fine structure in the middle latitude ionosphere known as the strip-like plasma density bulge. These bulges emerge during geomagnetic storms, exhibiting a broad longitudinal span of over 150° and a narrow latitudinal extent of 1°~5°. The observations from the DMSP and ICON satellites reveal stronger equatorward ion drifts and neutral winds on the poleward side of bulges compared to the equatorward side. Using the Sami2 is Another Model of the Ionosphere (SAMI2), the bulge feature was reproduced for the storm of 4~6 November 2021 by amplifying the default meridional winds. Numerical simulations indicate that global wind disturbances establish a sharp meridional wind gradient within the lower mid-latitude region. This gradient, in turn, drives a divergence in ion transport parallel and perpendicular to the magnetic field lines, which ultimately results in the localized accumulation of plasma. The phenomenon is most pronounced in the vicinity of ±30° quasi-dipole latitude. This region is characterized by a magnetic inclination angle of approximately 45°, a configuration where the meridional wind component acts most efficiently to elevate ions vertically.

How to cite: Du, W., Zhong, J., and Wan, X.: Storm-Time Strip-Like Plasma Density Bulges at Middle Latitudes Shaped by Meridional Wind Gradients, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-3064, https://doi.org/10.5194/egusphere-egu26-3064, 2026.

How to cite: Encrenaz, T., Greathouse, T., Marcq, E., Shao, W., Lefèvre, F., Giles, R., Lefèvre, M., Widemann, T., Bézard, B., and Sagawa, H.: Simultaneous mapping of CO, SO2 and HDO on the night side of Venus , EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-22816, https://doi.org/10.5194/egusphere-egu26-22816, 2026.

Abstract

Meteorite impacts can lead to significant disruptions of Earth’s systems, potentially affecting the planet's climate, ecosystems, and environment. The Manicouagan impact event is recorded by one of the largest impact craters of the Phanerozoic era, located in Quebec, Canada in the Grenville Province of the Canadian Shield, with a rim-to-rim diameter of 85–100 km. It has a precise age of 215.40 ± 0.16 Ma, yet its environmental aftermath remains poorly constrained, particularly any robust link to the Norian, Late Triassic extinction pulses or carbon-cycle perturbations. Here we present a new impact-Simplified Arbitrary Lagrangian-Eulerian (iSALE) hydrocode simulation against the Manicouagan’s target lithologies to constrain the most plausible impactor diameters and velocities that would reproduce the observed crater morphology. Three best-fit models of crater diameters and velocities of 7.2 km at 20 km s^-1, 8.8 km at 15 km s-¹, and 10.4 km at 12 km s^-1 reproduced crater diameters of 90, 95, and 100 km, respectively. We calculated the kinetic energy delivered by each projectile, which is on the order of 1.17–1.27x10²³ J. The calculated energy is sufficient to vaporize the entire projectile and a considerable amount of the upper target lithologies, and melt large volumes of the target rocks. We then estimated the mass of vapor released into the atmosphere by using scaling relations and assessed the potential post-initial settling of the vapor mass after condensation and re-entry to be ~5x10¹⁷ g. This exceeds the ~10¹⁶ g blackout threshold required to cause global cessation of photosynthesis, darkness, and cooling. Our results provide numerical assessments of the environmental consequences of the Manicouagan impact event and a framework for reassessing its potential role in Late Triassic biotic and climatic events.

Keywords

Manicouagan Impact Event, Hydrocode modeling, iSALE simulations, Late Triassic, Environmental consequences.

How to cite: Salem, S., Al-Suwaidi, A., and El-Maarry, M.: A New Impact Model for The Norian, Late Triassic Manicouagan Crater, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-8876, https://doi.org/10.5194/egusphere-egu26-8876, 2026.