OPS4

Juno’s low-light sensitive Stellar Reference Unit (SRU) navigation camera has embarked on Juno’s Extended Mission as a full-fledged member of the science payload. SRU images from Juno’s Prime Mission led to multiple discoveries within the Jovian system, inspiring new objectives that the orbit’s evolution will soon put within reach. SRU images of Jupiter’s dark side revealed the presence of “shallow lightning” flashes with origins in high altitude ammonia-water clouds above the 2 bar level. These observations fortify theories in which ammonia-water hailstones (“mushballs”) transport ammonia into Jupiter’s deep atmosphere, accounting for the ammonia variability observed at depth by Juno’s Microwave Radiometer (MWR). Images of Jupiter’s faint dust ring have been acquired from unique vantage points while inside the ring looking out, and while observing the shadow line cast by Jupiter across the dust. In June 2021, the SRU imaged Ganymede’s dark side at >79 degrees illumination angle and <920 m/pixel resolution while the surface was illuminated only by Jupiter-shine. This novel use of a low-light star tracker resolved multiple craters, surface features (such as grooved terrain), and an unusual elongated ejecta deposit in Xibalba Sulcus. These features are not resolved in the Voyager and Galileo imagery used for the USGS global geologic map of Ganymede. Our discussion will focus on proposed updates to Ganymede’s geologic record and SRU ring science. A preview of upcoming SRU observations to investigate the influence of Jupiter’s shallow thunderstorms on Jupiter’s deep atmospheric dynamics (during the dark side perijoves starting in 2023) will also be included.

How to cite: Becker, H., Florence, M., Brennan, M., Hansen, C., Schenk, P., Ravine, M., Arballo, J., Bolton, S., Lunine, J., Guillaume, A., and Alexander, J.: Jovian Satellite and Ring Observations from the Juno Stellar Reference Unit, plus Plans for the Dark Side Perijoves, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-95, https://doi.org/10.5194/epsc2022-95, 2022.

As observed for over 100 years, Jupiter's atmosphere has been characterized by a well-organized system of zones and belts disrupted by storms and vortices such as the Great Red Spot (GRS).  Jupiter’s meteorologically-active weather layer, where storms, vortices, and convective clouds are observed, was expected to be constrained to relatively shallow depths above the levels where water condensation and latent heat release might be an important driver of convection.  Early results from Juno extended the puzzle by discovering that both ammonia and water vary across most of the planet at much greater depths than their expected saturation levels.

The Microwave Radiometer (MWR) instrument on the Juno spacecraft provides a new and unique view into giant planetary atmospheres, using a set of radiometers operating at a range of frequencies that interrogate depths from the upper troposphere down to more than 600 km beneath the visible cloud tops.  As part of Juno, an unprecedented collaboration between ground- and space-based observations has been organized to help interpret the MWR and other Juno data.  Infrared images and spectroscopy from Juno’s Jovian Infrared Auroral Mapper (JIRAM) instrument, as well as from Earth-based observatories, provide compositional boundary conditions for the interpretation of the MWR data.  Spatial context comes from color imaging by JunoCam on Juno and from HST, together with ground-based imaging spanning the UV to the IR.  We present preliminary results of a study on the dynamics inside Jupiter’s atmosphere relating the cloud and storm features observed at shallow depths to the deeper atmospheric dynamics detected by the MWR.

How to cite: Bolton, S. and the Juno MWR Science Team: Exploring the depth of weather storms and vortices in Jupiter’s atmosphere, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-174, https://doi.org/10.5194/epsc2022-174, 2022.

Since 2010 several amateur astronomers have discovered flashes of light that result from the collision of objects of 5-20 m in diameter, impacting in Jupiter’s atmosphere at velocities higher than 60 km/s. These objects release energies of the order of 10¹⁵-10¹⁶ J, or 200-1000 kiloton [1] and become observable even with small-size telescopes. Up to 2019, 6 such impact flashes have been observed by amateur astronomers [2-3]. In one case, the quality of the light-curve allowed to investigate the physical composition of the impacting object through the effect of its density when comparing with models of impacts and with the likely conclusion of a stony composition [4]. An important step forward has been the availability of software tools that allow to check video files of Jupiter to automatically search for the faint trace of an impact. The software DeTeCt is a free-software designed for the task [5] and available at: http://www.astrosurf.com/planetessaf/doc/project_detect.php

Here we report the characteristics of 3 additional impacts detected in 2020-2021. These were a very bright flash discovered on 13 September, which was simultaneously observed by at least 9 observers from Brazil to Germany. A new impact was discovered by Kothji Arimatsu from Kyoto University on 15 October 2021, running a dedicated telescope with two CMOS cameras, and also observed by amateur astronomers in Japan and Singapore. After finding this impact, one of these observers used the DeTeCt software on past observations acquired one year earlier on 11 Aug. 2020 finding an additional impact that had passed unnoticed. These 3 impacts in 2020 and 2021 were observed by a variety of cameras with different sensitivities to color. This allows a good quantification of the effective brightness temperature of the impact and a more accurate measurement of the energy released, and thus, a better estimation of the mass of the impactor. The event observed on 13 September 2021 was the brightest flash observed in Jupiter. The 15 October 2021 event was also brighter than most previous flashes and it impacted Jupiter in an area observed by the Junocam instrument 28 hours later. However, Junocam did not observe a remnant even at a spatial resolution over the impact area of ~30 km/pix. We present light-curves of these three impacts and their brightness temperatures from multi-wavelength observations. Brightness temperatures compare well with the spectra of a smaller impact observed in 2018 by the Juno mission [8]. From the light-curves and brightness temperatures we deduce masses, sizes and how these 3 new objects,  and the combined data of the DeTeCt project set ups new constrains in the current impact rate in the Jupiter System [3, 7]. We also evaluate the quality of the structures observed in the simultaneous lightcurves and their capability to constrain models of bolides impacting Jupiter’s atmosphere [2,4].

Figure: Composite images of the three impacts discussed in this work together with multi-wavelength lightcurves of the central impact from one of the colour videos obtained. The rate between blue and red is indicative of a high brightness temperature.

Acknowledgments

We are very grateful to all the observers of these impacts supplying the observations and reports used in this analysis. These are: (1) Victor PS Ang (Singapore), who observed the 2020-08-11 impact and was one of the 3 amateur observers of the 2021-11-15 impact. (2) Jose Luis Pereira (Brazil), Harald Paleske (Germany), Jean-Paul Arnould (France), Didier Walliang (France), Michel Jacquesson (France), Cosmin Sabdu Val (Romania), Jean-Christophe Griveau (France), who all observed and recorded videos of the 2020-09-13 impact together with additional colleagues operating their telescopes. In addition Maciej Libert (Germany), Simone Galelli (Italy) both reported visual observations of the impact looking at the eyepiece of their telescopes. (3) “Yotsu” (Japan) and Yasunobu Higa (Japan) who were two of the observers of the 2021-11-15 impact. We are also grateful to Kothji Arimatsu and the PONCOTS team from Kyoto Observatory for comments on the October 2021 impact they originally discovered and announced making possible its detection in amateur videos acquired from Singapore and Japan. In addition, we are extremely grateful to the many amateur astronomers taking part in the DeTeCt project and committing a large amount of their time to look for impacts.

References

[1] Hueso, R., Wesley A. et al. (2010). First Earth-based detection of a superbolide on Jupiter, The Astrophysical Journal Letters (721), 2010.

[2] Hueso, R. et al. (2013). Impact flux on Jupiter: From superbolides to large-scale collisions. Astronomy & Astrophysics, 560, A55.

[3] Hueso, R., Delcroix, M. et al. (2018). Small impacts on the giant planet Jupiter, Astronomy & Astrophysics, A68.

[4] Sankar, R. et al. (2020). Fragmentation modelling of the August 2019 impact on Jupiter, Montly Notices of the Royal Astronomical Society, 493, 4622-4630.

[5] Hueso, R. Et al. (2018). Detectability of possible space weather effects on Mars upper atmosphere and meteor impacts in Jupiter and Saturn with small telescopes. Journal of Space Weather and Space Climate, 8, A57.

[6] Delcroix, M. et al. (2019). Jupiter impact detection project, Europlanet Science Conference, EPSC2019-970.

[7] Delcroix, M. et al. (2020). Impact detection on Jupiter through amateur’s processing of their own videos using DeTeCt, Europlanet Science Conference, EPSC2020-775.

[8] Giles, R. S. et al. (2021). Detection of a Bolide in Jupiter’s atmosphere with Juno UVS, Geophysical Research Letters, 48, e2020GL091797.

How to cite: Hueso, R., Delcroix, M., Sánchez-Lavega, A., Sánchez-Arregui, M., Palotai, C., and Boslough, M.: Bolide Impacts in Jupiter’s Atmosphere in 2020-2021, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-220, https://doi.org/10.5194/epsc2022-220, 2022.

The thousands of exoplanets that have already been discovered launched an unprecedent drive towards the exploration of these new worlds, particularly their atmospheres. Many of these new planets fit the profile of a gas giant, although with a wide range of characteristics. To study these far away objects, we often use the Solar System as a starting point, thus a good knowledge of the atmospheres of these objects is paramount to understand these other worlds. In this regard, Jupiter often serves as model gas giant, due to its size and mass combination, among other parameters. However, despite numerous interplanetary and orbiting spacecraft combined with a long record of Earth-based observations, some fundamental questions regarding dynamical processes in Jupiter's atmosphere remain [Fletcher et al. (2020)]. The vertical structure of the colourful clouds we see with a small-sized telescope and their circulation mechanisms are still elusive [Sanchez-Lavega (2011)]. Also, to study the atmosphere dynamics of solar system planets, particularly its behaviour and evolution with time, continuous observations are required [Hueso et al. (2020)].

Multiple records of detailed observations span across more than 30 years, from first analysis of the zonal winds [Limaye et al. (1986), Vasavada et al. (1998)] using Pioneer and Galileo data, to more detailed views from the Cassini flyby [Porco et al. (2003), Salyk et al. (2006), Garcia-Melendo et al. (2011), Galperin et al. (2014)]. The most recent efforts in this regard are attributed to the Juno mission, which contributes with very high spatial resolution images [Hansen et al. (2017)], supported by observation campaigns from the Hubble Space Telescope [Garcia-Melendo et al. (2001), Tollefson et al. (2017), Hueso et al. (2017), Johnson et al. (2018)]. Although an impressive volume of data, winds at tropospheric levels have mostly been obtained with cloud-tracking techniques, which follow large patterns moving in the observable atmosphere of Jupiter. Recent efforts in studying the dynamics of the tropospheric region of Jupiter with other techniques such as high-resolution spectroscopy are gaining momentum, with the improvement of facilities which enable increased spectral resolution [Gaulme et al. (2018), Goncalves et al. (2019)].

Different techniques, such as high resolution spectroscopy applied to planetary atmospheres of the Solar System to study dynamics, can be complementary to the usually employed cloud-tracking method, by targeting slightly different levels of the atmosphere [Machado et al. (2021)], with the possibility therein to study the vertical wind shear. The technological capabilities of modern facilities that were designed to discover exoplanets can also be taken advantage of to observe Solar System atmospheres, achieving unprecedent levels of precision from the ground [Gonçalves et al. (2020)]. One such facility is ESPRESSO, assembled on the Very Large Telescope, at ESO. ESPRESSO is able to get two simultaneous spectra in a wavelength range between 378.2 and 788.7 nm with a resolving power that ranges from 70,000 in the Medium Resolution mode (MR) to more than 190,000 in the Ultra High Resolution mode (UHR) [Pepe et al. (2021)]. ESPRESSO was originally designed for exoplanet hunting and atmospheric characterisation, however, just as was demonstrated in [Gonçalves et al. (2020)] for HARPS-N, using these very high resolution spectrographs on solar system atmospheric characterisation can open new horizons on what is possible to achieve with ground-based instruments to study large objects in our cosmic vicinity.

We present an optimised Doppler velocimetry method, originally used to retrieve winds on Venus' cloud top region in the visible part of the spectrum [Widemann et al. (2008), Machado et al. (2012), Machado et al. (2014), Machado et al. (2017)]. With its successful application to Venus, this work presents an exploration of other targets within the solar system with our method. It is also an opportunity to investigate the effectiveness of ESPRESSO in the study of Solar System atmospheres, since it was used for this purpose for the first time. We show zonal wind speeds at equatorial latitudes using all the lines in the visible spectrum, from solar radiation backscattered on Jupiter’s atmosphere. These results are compared with the plethora of wind velocity data already retrieved in Jupiter’s troposphere for validation, finding consistency between both methods, despite our limited spatial and temporal coverage.

This work promotes another step in the exploration of other Solar System targets with ground-based observations, to fill the gap left by the limited availability of interplanetary space missions, ensuring continuous monitoring of the evolution of the atmospheric circulation on those planets at high spectral resolutions.

References

• Fletcher, L.N., et al. (2020), PSJ, 216, article id. 30, DOI: 10.1007/s11214-019-0631-9;
• Galperin, B., et al. (2014), Icarus, 229, pp. 295-320, DOI: 10.1016/j.icarus.2013.08.030;
• Garcia-Melendo, E., Sanchez-Lavega, A., (2001), Icarus, 152, pp 316-330, DOI: 10.1006/icar.2001.6646;
• Gaulme, P., et al. (2018), A&A, 617, article id. A41, DOI: 10.1051/0004-6361/201832868;
• Gonçalves, I., et al. (2019), Icarus, 319, pp. 795-811, DOI: 10.1016/j.icarus.2018.10.019;
• Gonçalves, R., et al. (2020), Icarus, 335, article id. 113418, DOI: 10.1016/j.icarus.2019.113418;
• Hansen, C.J., et al., (2017), Spc. Sci. Rev., 243, pp. 475-506, DOI: 10.1007/s11214-014-0079-x;
• Hueso, R., et al. (2017), Geophys. Res. Lett., 44, pp. 4669-4678, DOI: 10.1002/2017GL073444
• Johnson, P.E., et al. (2018), Nat. Lett., 155, pp. 2-11, DOI: 10.1016/j.pss.2018.01.004;
• Limaye, S.S., (1986), Icarus, 65, pp. 335-352, DOI: 10.1016/0019-1035(86)90142-9;
• Machado, P., et al. (2012), Icarus, 221, pp. 248-261, DOI: 10.1016/j.icarus.2012.07.012;
• Machado, P., et al. (2014), Icarus, 243, pp. 249-263, DOI: 10.1016/j.icarus.2014.08.030;
• Machado, P., et al. (2017), Icarus, 285, pp. 8-26, DOI: 10.1016/j.icarus.2016.12.017;
• Machado, P., et al. (2021), Atmosphere, 12, nº506, DOI: 10.3390/atmos12040506;
• Pepe, F., et al. (2021), A&A, 645, A96, DOI: 10.1051/0004-6361/202038306;
• Porco, C., et al. (2003), Science, 299, nº1541, DOI: 10.1126/science.1079462;
• Salyk, C., et al. (2006), Icarus, 185, pp. 430-442, DOI: 10.1016/j.icarus.2006.08.007;
• Sanchez-Lavega, A. (2011), CRC Press, 1^st, Taylor & Francis Group;
• Tollefson, J., et al. (2017), Icarus, 296, pp. 163-178, DOI: 10.1016/j.icarus.2017.06.007;
• Vasavada, A.R., et al. (1998), Icarus, 135, pp. 265-275, DOI: 10.1006/icar.1998.5984;
• Widemann, T., et al. (2008), Planet. Space Sci., 56, pp. 1320-1334, DOI: 10.1016/j.pss.2008.07.005.

How to cite: Silva, J. E., Machado, P., Brasil, F., Gonçalves, R., and Silva, M.: Jupiter's banded circulation through the eyes of VLT/ESPRESSO, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-221, https://doi.org/10.5194/epsc2022-221, 2022.

The study of the thermal spectrum of Jupiter gives us the possibility to study the elements that constitute the Jovian atmosphere, allowing us to infer the formation history and conditions of the giant planet (Taylor et al., 2004). Determining the abundance of chemical species and isotopic ratios is fundamental in this regard. For this, we reanalyse 1997 Jupiter data obtained by the ESA mission Infrared Space Observatory (ISO) (Kessler et al., 1996) in the 793.65-3125 cm-1 (3.2-12.6 µm) region using the Short-Wave Spectrometer (SWS) (de Graauw et al., 1996).  Despite the age of this data, we argue that it warrants a revisit and reanalysis since it was an important step in the study of Jupiter’s atmosphere and there have since been advancements in atmospheric models and line data.

In this work we used the NEMESIS radiative transfer suite (Irwin et al. 2008) to reproduce the observations from Encrenaz et al. (1999), which will also work as a validation of our method. Using the Cassini/CIRS model as a starting point, we adapted the template for the ISO/SWS data. We compiled correlated k-tables from the spectral line database from Fletcher et al. (2018) for a NH₃, PH₃, ¹²CH₃D, ¹²CH₄, ¹³CH₄, C₂H₂, C₂H₆, C₂H₄, C₄H₂, He and H₂ atmosphere.

Figure 1: Plot of ISO/SWS and CIRS observations showing the discrepancy between both (no offset applied)

We first compare the spectrum obtained by ISO/SWS with the a priori model in order to find discrepancies between them as well as how each molecule individually impacts the forward model (Figure 1).

Our current work is focused on the 793.65-1500 cm^-1 (6.7-12.6 µm) region of the spectrum, for comparison reasons between the CIRS and ISO-SWS data, with the 793.65-1200 cm^-1 (8.3-12.6 µm) region showing the best fit.

We present here our preliminary results of the study of abundances of ¹²CH₃D, ¹²CH₄, ¹³CH₄, C₂H₂ and C₂H₆ of Jupiter’s atmosphere as well as our study of the pressure-temperature profile of Jupiter obtained using NEMESIS retrievals. We also compare our results with the profiles and abundances from Neimann et al. (1998) and Fletcher et al. (2016) with the aim of constraining the number of possible best fit profiles.

As consequence of the former study, we also present our initial study of the H/D and ¹²C/¹³C isotopic ratio of the Jovian atmosphere from the abundances of ¹²CH₃D, ¹³CH₄ and ¹²CH₄ following the methodology from Fouchet et al. (2000).

We hope with this work to advance the understanding of the atmosphere of Jupiter and the physical and chemical processes that occur, as well as better determining its vertical distribution of chemical species and thermal profile. As future work, we expect to extend our frequency domain to the full range of ISO/SWS observations, study the ¹⁵N/¹⁴N ratio and compare our finding with other relevant results.

References:

• de Graauw et al., Observing with the ISO short-wavelength spectrometer, A&A 315, L49-L54, 1996
• Encrenaz et al., The atmospheric composition and structure of Jupiter and Saturn form ISO observations: a preliminary review, Planetary and Space Science 47, 1225-1242, 1999
• Fletcher et al., Mid-infrared mapping of Jupiter’s temperatures, aerosol opacity and chemical distributions with IRTF/TEXES, Icarus 278, 128–161, 2016
• Fletcher et al., A hexagon in Saturn's northern stratosphere surrounding the emerging summertime polar vortex, Nature Communications, Volume 9, 2018.
• Fouchet et al., ISO-SWS Observations of Jupiter: Measurement of the Ammonia Tropospheric Profile and of the 15N/14N Isotopic Ratio, Icarus 143, 223–243, 2000
• Irwin et al., The NEMESIS planetary atmosphere radiative transfer and retrieval tool, Journal of Quantitative Spectroscopy & Radiative Transfer 109, 1136–1150, 2008
• Kessler et al., The Infrared Space Observatory (ISO) mission, A&A 315, L27, 1996
• Neimann et al., The composition of the Jovian atmosphere as determined by the Galileo probe mass spectrometer, Journal of Geophysical Research Atmospheres 103(E10):22831-45, 1998
• Taylor et al., Jupiter, The Planet, Satellites and Magnetosphere, Ch.4, Cambridge Planetary Science, Eds. Bagenal, Dowling, McKinnon, 2004

Acknowledgements:

We thank Thérèse Encrenaz, from LESIA, Observatoire de Paris, for providing the data for this work, Patrick Irwin, from the University of Oxford (UK), for the help with the NEMESIS radiative transfer suite and Maarten Roos-Serote for guidance and help in analysing the data and retrieval results.

We acknowledge support from the Portuguese Fundação Para a Ciência e a Tecnologia (ref. PTDC/FIS-AST/29942/2017) through national funds and by FEDER through COMPETE 2020 (ref. POCI-01-0145 FEDER-007672) and through a grant of reference 2021.04584.BD. 

How to cite: Ribeiro, J., Machado, P., Pérez-Hoyos, S., Dias, J., and Irwin, P.: Preliminary atmospheric study of Jupiter using ISO/SWS data, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-257, https://doi.org/10.5194/epsc2022-257, 2022.

Introduction

The Great Red Spot of Jupiter (GRS) is the largest and longest-lived anticyclone in the Solar System. First observed probably in the XVII century, it is one of the most remarkable dynamical phenomena in any known atmosphere. The structure, coloration and dynamical behavior of the Jovian anticyclone are severely affected by the formation and evolution of the GRS upper hazes, making them a relevant field of study.

The distinctive reddish color of the GRS (see Figure 1) is due to the nature and vertical distribution of the hazes over it. Carlson et al. (2016) proposed a possible chromophore to explain the GRS coloration: the products from photolyzed ammonia reacting with acetylene. Sromovsky et al. (2017) showed that this species was able to explain the reddish colorations all over the planet, despite being of very different intensity. This chromophore must be located on top of the tropospheric haze, in the so called “crème brûlée” model. Anguiano-Arteaga et al. (2021) performed a radiative transfer analysis that showed the existence of a stratospheric haze that could be compatible with the chromophore agent proposed by Carlson et al. (2016), although their study also suggested another chromophore located below that, in the upper tropospheric levels. However, every single color in the region shown in Figure 1 was also explained with those two chromophores.  In a recent paper (Anguiano-Arteaga et al., 2022) we find that the results of Anguiano-Arteaga et al. (2021) remain valid at least from 2015 to 2021, and no major temporal variations are expected in years close to such time span.

Figure 1. Map showing Jupiter’s Great Red Spot in December 2016. The RGB images are constructed from HST/WFC3 images with R=F631N, G=F502N and B=F395N. Image taken from Anguiano-Arteaga et al. (2022).

Vertical structure of the GRS

Images taken in filters sensitive to the altitude of the clouds and hazes show that the cloud top of the GRS is higher than its environment. The altitude of the hazes plays a major role in the coloration and dynamics. For example, in the scheme proposed by Carlson et al. (2016) material in the GRS raises to upper pressure levels and undergoes photochemical reactions that lead to the creation of the coloring agent. The amount of material high in the atmosphere would be then a fundamental factor to determine the production rate of chromophore species. Radiative transfer analyses give some insight on the altitude of the clouds and hazes. In Figure 2, we show maps of cloud top effective altitudes obtained from radiative transfer spectral modeling, as shown in Anguiano-Arteaga et al. (2021, 2022). However, radiative transfer analyses cannot provide some important information on the hazes, such as chromophore production rates or timescales of the undergoing atmospheric processes (e.g., coagulation, condensation and sedimentation). Because of this, microphysical considerations should be also taken into account in order to get a more complete description of the nature, structure and evolution of the hazes.

Figure 2. Map of the GRS area in December 2016 showing the pressure levels (in mbar) where the optical depth at 900 nm equals unity. This map is interpreted as the cloud top effective altitude.

Microphysical study

In this work, we perform microphysical simulations of the GRS hazes in the stratosphere and upper troposphere (P < 500 mbar). For this purpose, we develop a 1-D numerical code that takes into account the effects of particle sedimentation, coagulation, eddy diffusion and aerosol growth by molecular condensation. We report here results on the particle size distribution as a function of altitude, together with aerosol concentrations and timescale analysis regarding different microphysical processes. This constrains the mass production rates required to explain the chromophore model and hence serves as a test for any given proposed candidate. The results are interpreted according to prior findings following radiative transfer analysis on the GRS.

References

- Anguiano-Arteaga, A., Pérez-Hoyos, S., Sánchez-Lavega, A., Sanz-Requena, J. F., & Irwin, P. G. J. (2021). Vertical distribution of aerosols and hazes over Jupiter's Great Red Spot and its surroundings in 2016 from HST/WFC3 imaging. J. Geophys. Res. Planets., 126, e2021JE006996 https://doi.org/10.1029/2021JE006996

- Anguiano-Arteaga, A., Pérez-Hoyos, S., Sánchez-Lavega, A., Sanz-Requena, J. F., & Irwin, P. G. J. (2022). Temporal variations in vertical cloud structure of Jupiter’s Great Red Spot, its surroundings and oval BA from HST/WFC3 imaging. Submitted to J. Geophys. Res. Planets.

- Carlson, R.W., Baines, K.H., Anderson, M.S., Filacchione, G., & Simon, A.A. (2016). Chromophores from photolyzed ammonia reacting with acetylene: Application to Jupiter’s Great Red Spot. Icarus, 274, 106-115. https://doi.org/10.1016/j.icarus.2016.03.008

- Sromovsky, L.A., Baines, K.H., Fry, P.M., & Carlson, R.W. (2017). A possibly universal red chromophore for modeling color variations on Jupiter. Icarus, 291, 232-244. https://doi.org/10.1016/j.icarus.2016.12.014

How to cite: Anguiano-Arteaga, A., Pérez-Hoyos, S., and Sánchez-Lavega, A.: Formation and structure of hazes over Jupiter’s Great Red Spot, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-324, https://doi.org/10.5194/epsc2022-324, 2022.

Introduction

The detailed observations by the NASA Juno spacecraft has advanced Jupiter’s interior structure models which can be used to improve our understanding of Jupiter’s origin. In this study, we investigate the potential origin of Jupiter's enriched atmosphere. We revisit the planetesimal accretion during Jupiter’s formation: in previous studies, the planetesimal accretion rate is calculated using N-body simulations that model the swam of planetesimals around proto-Jupiter. It was concluded that the heavy-element enrichment in Jupiter's envelope can be explained by the planetesimal accretion if Jupiter formed in a planetesimal disk that is at least five times more massive than the minimum mass solar nebulae (MMSN). However, this conclusion was inferred under the assumption that the total mass of captured planetesimals linearly increases with the surface density of planetesimals. In reality, in such a massive disk the gravitational interactions between planetesimals and embryos becomes so strong that the initial eccentricity and inclination are excited to 〜0.1 at most. In this study, we investigate this scenario in detail accounting for the change of the eccentricity and inclination of the planetesimals and show its affect off Jupiter’s growth rate and final composition.

Model

Figure 1: The surface density of planetesimals used in this study. This surface density profile is obtained by Kobayashi & Tanaka (2021).

We adopt a planetesimal disk obtained by Kobayashi & Tanaka (2021) where the collisional evolution of dust grains in the protoplanetary disk results in a dense-compact planetesimal disk because of pebble drift from the outer disk. Figure 1 shows the surface density profile of planetesimals we use in this study. We start the N-body simulations with a swam of planetesimals around proto-Jupiter which enters the runaway gas accretion phase and increases its mass from 10 M_⊕ to 318 M_⊕. During its formation, we assume that proto-Jupiter slightly migrates inward due to type II migration. If a planetesimal collides on the surface of proto-Jupiter or loses its escape energy from Jupiter's Hill sphere, we assume that the planetesimal is captured by proto-Jupiter.

We set the initial eccentricities and inclinations of planetesimals as input parameters. Since the choice of the planetesimal’s size can significantly affect the accretion rate we consider various planetesimal sizes.

Results

Figure 2: The cumulative mass of captured planetesimals as a function of time. Black, red, green and blue lines show correspond to different assumed initial eccentricities of ‹e₀›^1/2=10^-3,10^-2,10^-1, and 0.4, respectively. The initial inclination is set as   ‹i₀›^1/2=0.5‹e₀›^1/2.

In a massive planetesimal disk, proto-Jupiter accretes tens Earth-masses of heavy elements by the end of runaway gas accretion. Figure 2 shows the cumulative mass of captured planetesimals vs. time. We find that the increase of the initial eccentricity and inclination:

• weakens resonant trapping and leads to an enhancement of planetesimal accretion,
• reduces the capture probability of planetesimals.

Due to the combination of these effects, the captured mass of planetesimals decreases with the increase of the initial eccentricity and inclination.

Discussion

Figure 3: Total mass of captured planetesimals as a function of planetesimal size and the initial eccentricity. The initial inclination is set as   ‹i₀›^1/2=0.5‹e₀›^1/2. The solid and dashed black line shows the equilibrium eccentricity of planetesimals with and without embryos, respectively.

The initial eccentricity and inclination of planetesimals are determined by the scattering from other planetesimals/embryos. In a massive planetesimal disk as assumed here, embryos other than proto-Jupiter would form and be in the “oligarchic regime”. Considering the eccentricity and inclination excitation from the embryos, we conclude that the total mass of captured planetesimals is about 5-10 M_⊕, and is larger for larger planetesimals.

The bulk metallicity of Jupiter is still a matter of debate (e.g., Stevenson 2020). Planetesimal accretion could explain structure models with ~10 M_⊕ of heavy elements in Jupiter’s outer envelope. However, if Jupiter’s enrichment is found to be higher, as suggested by some structure models (e.g., Miguel et al. 2022), an additional enrichment mechanism would be required. Such an enrichment could be a result of giant impacts of embryos. Such impacts have been suggested by Liu et al. (2019) for the formation of Jupiter’s fuzzy core.

We also compare our results with those presented by Shibata & Helled (2022), where planetesimal accretion was considered for the case of a migrating Jupiter from 20 au to 5 au. We find that the timing of planetesimal accretion must occur earlier for the in-situ formation case, which enriches Jupiter's interior rather than the outer envelope or atmosphere. We suggest that a determination of the heavy-element distribution in Jupiter’s envelope could constrain Jupiter’s formation location and formation history.

References

Kobayashi, H., & Tanaka, H. 2021, ApJ, 922, 16, doi: 10.3847/1538-4357/ac289c

Liu, S.-F., Hori, Y., M ̈uller, S., et al. 2019, Nature, 572, 355, doi: 10.1038/s41586-019-1470-2

Miguel, Y., Bazot, M., Guillot, T., et al. 2022, arXiv e-prints, arXiv:2203.01866. https://arxiv.org/abs/2203.01866

Shibata, S., & Ikoma, M. 2019, MNRAS, 487, 4510, doi: 10.1093/mnras/stz1629

Shibata, S., & Helled, R. 2022, ApJL, 926, L37, doi: 10.3847/2041-8213/ac54b1

Stevenson, D. J. 2020, Annu. Rev. Earth Planet. Sci., 48, 465

How to cite: Shibata, S., Helled, R., and Kobayashi, H.: Revisiting Planetesimal Accretion onto Proto-Jupiter, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-427, https://doi.org/10.5194/epsc2022-427, 2022.

Jupiter’s cyclonic features are known to undergo transitions between quiescent states with smooth edges (often appearing as dark brown ‘barges’) to states with convective outbursts of billowing white clouds, chaotically churned into filamentary structures.  Cyclones in the latter state are known as ‘Folded Filamentary Regions’ (FFRs), and Voyager images (Ingersoll+1979, doi: 10.1038/280773a0) revealed them to be rapidly-varying turbulent regions, occurring in cyclonic domains on the poleward side of Jupiter’s prograde jets.  JunoCam visible-light observations (Orton+2017, doi:10.1002/2016GL072443, Rogers+2021, doi:10.1016/j.icarus.2021.114742), reveal the increasing prevalence of FFRs at mid-to-high latitudes.  They dominate the polar domain alongside smaller anticyclonic white ovals, drifting westward in latitude bands between the narrow prograde jets, and rapidly evolving over timescales of days. 

The present study makes use of Juno’s ever-improving microwave observations of the north polar domain, as the latitude of closest-approach (“perijove”) moves northward.  We therefore focus on FFRs in the northern hemisphere, where we find them to occur in zonally-organised latitude bands even at high latitudes.  Statistics of the FFRs suggest that they occur on the poleward sides of the N4 (43.3^oN, centric), N5 (52.3^oN), and N7 (66.1^oN) prograde jets (N6 at 61.2^oN coincides with a ‘bland zone’ lacking notable FFRs), and scattered in the polar domain up to the octagon of circumpolar cyclones at 85^oN.  JIRAM 5-µm imaging of both poles reveal FFRs as generally dark structures with elevated aerosol opacity blocking thermal infrared emission from the 4-6 bar level, coinciding with the white stratiform clouds observed by JunoCam. Clusters of small cumulus-like clouds, as well as curvilinear cloud streaks, provide texture to the flat stratiform clouds to give the appearance of a network of filaments.  Visibly-dark lanes border the brighter filaments, creating an intricate network of narrow, aerosol-free, and 5-µm-bright striations within each FFR.  This is in contrast to cyclonic features such as barges at lower latitudes, where an absence of overlying aerosols generally renders them 5-µm bright. 

A survey of 1.4-50 cm observations acquired by Juno’s Microwave Radiometer (MWR) between PJ20 (May 2019) to PJ37 (October 2021) reveals that FFRs share a key characteristic with their low-latitude counterparts:  they are microwave-bright in channels sounding the 0.6-2.0 bar range (1.4-3.0 cm), become hard to distinguish from their surroundings near 5 bars (5.75 cm), but are then microwave-dark in the channel sounding 10-15 bar (11.5 cm). This suggests FFRs are depleted in ammonia gas and/or locally warmer at levels above the putative location of Jupiter’s water cloud, the latter implying a decay of cyclonic winds with altitude.  This shallow ammonia depletion is surprising, given the apparent convective nature of the FFRs - maybe NH₃-rich plumes occupy a sufficiently small area of the cyclonic structure, so that they have negligible impact on the warm emission observed by MWR.  This shallow depletion is balanced by a local NH₃ enrichment (or local cooling) at depth, below the water cloud, like a cyclonic lens.  However, the extension of FFR signatures to deeper levels (p>20 bars) is currently unclear due to insufficient spatial coverage and resolution at the longest-wave channels, and confusion arising from auroral contributions to the MWR dataset at 50 cm.  

An inversion in microwave brightness with depth was previously identified for Jupiter’s larger-scale belts and zones (Fletcher+2021, doi:10.1029/2021JE006858) and mid-latitude discrete features (Bolton+2021, doi:10.1126/science.abf1015), and now appears to be common at high latitudes as well.  Geostrophy implies that cyclonic circulations (low-pressure centers) cause a rise in potential-temperature surfaces in deeper layers, potentially triggering moist convection in the water cloud (e.g., Dowling & Gierasch, 1989 Bull. Amer. Astron. Soc 21, 946; Fletcher+2017, doi:10.1016/j.icarus.2017.01.001), producing the distinct convective cloud structure observed by visible and infrared imaging: juxtaposed tall convective towers, deep water clouds, and narrow clear lanes (Imai+2020, doi:10.1029/2020GL088397). Lightning sferics measured by MWR at 50 cm/600 MHz are more frequent in the N4, N5, and N7 domains where FFRs are common (Brown+2018, doi:10.1038/s41586-018-0156-5), and are further clustered in FFRs themselves (Wong+2020, doi:10.3847/1538-4365/ab775f).  Thus the evolution of the cyclonic FFRs, and their penetration to the moist depths below the water condensation level, may hold the key to understanding the distribution of lightning activity on Jupiter.

How to cite: Fletcher, L., Oyafuso, F., Orton, G., Zhang, Z., Brueshaber, S., Wong, M., Li, C., Mura, A., Grassi, D., Melin, H., Levin, S., Bolton, S., Rogers, J., and Brown, S.: Juno Characterisation of Cyclonic “Folded Filamentary Regions” within Jupiter’s Polar Domains, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-475, https://doi.org/10.5194/epsc2022-475, 2022.

During its 53-day polar orbit around Jupiter, Juno often crosses the boundaries of the Jovian magnetosphere, namely the magnetopause and bow shock, as well as the plasma disc (located at the centrifugal equator). The positions of the magnetopause and bow shock allow us to determine the dynamic pressure of the solar wind (using both the updated model of Joy et al. 2002 by Ranquist et al., 2020 and/or in situ data) which allows us to infer magnetospheric compression or relaxation, while the observations of plasma disc perturbations allows us to infer magnetospheric reconfigurations.

The aim of this study is to examine Jovian radio emissions during magnetospheric perturbations. We then use our analysis to determine the relationship between the solar wind and Jovian radio emissions (observed and emitted from different regions of the magnetosphere, from different mechanisms, and at different wavelengths from kilometers to decameters).

In this presentation, we show case studies for each typical case (bow shock, magnetopause and plasma disk crossings) and show that the activation of new radio sources is related to magnetospheric disturbances. By performing a statistical study of these crossings, we hope to be able to show the relationship between the activation of new radio sources (emission intensity and extension, source positions) and the solar wind (dynamic pressure, magnetic intensity, ...), with the aim of being able to use observations of planetary radio emission as a proxy for the solar wind.

How to cite: Louis, C., Jackman, C., O’Kane Hackett, A., Devon-Hurley, E., Kurth, W., Hospodarsky, G., Louarn, P., Allegrini, F., Connerney, J., Weigt, D., McEntee, S., Fogg, A., Waters, J., and Bolton, S.: Effect of magnetospheric disturbances on Jovian radio emissions: an in situ case study from Juno data, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-534, https://doi.org/10.5194/epsc2022-534, 2022.

Measurements by Juno as the spacecraft flew by Ganymede on June 7^th of 2021 from the JADE instrument when combined with images from UVS of the aurora can be used to significantly advance our knowledge of the atmosphere and ionosphere. JADE measures the ion outflow composition that results from downgoing plasma electrons in the polar cap region and also measures the downward electrons associated with the reconnection at the boundary of Ganymede’s magnetosphere with the Jupiter magnetosphere. Modeling can help to check the consistency between the electron energy influx in the polar cap and the resulting ionospheric outflow and can also be used to set constraints on how reconnected electrons form the auroral atmosphere and the auroral emissions measured by UVS.

How to cite: Waite, J. H., Valek, P., Greathouse, T., Allegrini, F., Ebert, R., Gladstone, R., and Bolton, S.: What the JADE electron and ionospheric measurements told us about the aurora and atmosphere of Ganymede, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-267, https://doi.org/10.5194/epsc2022-267, 2022.

On June 7, 2021 Juno performed a close flyby of Ganymede. Here we study the high-resolution magnetic field spectrum which indicates that Juno travelled within Ganymede’s closed magnetic field line region for around 3 minutes during the closest approach. This result is supported by two main facts. 1) The harmonic structure in the spectrum of the high-resolution magnetometer data agrees very well with the frequencies predicted for resonances of a dipole field. 2) The inferred plasma density near the equator at 1.7 RG (L-shell of the closest approach) is approximately 25 amu/cm³, which is much lower than the local density of the plasma sheet near Ganymede (~100 amu/cm³). We also discuss our results together with those obtained by other Juno instruments and theoretical models.

How to cite: Martos, Y. M., Romanelli, N., Espley, J., Connerney, J., and Kotsiaros, S.: Field line resonances in Ganymede’s magnetosphere observed by Juno, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-719, https://doi.org/10.5194/epsc2022-719, 2022.

Io is the Solar System body showing the largest number of active volcanic centers, primarily generated by tidal heating [1]. Many ground based and remote sensing observations have revealed spatial and temporal variabilities, important to define the characteristics of tidal heating and the mechanisms by which heat escapes from the interior [2, 3, 4].

The Jovian Infrared Auroral Mapper (JIRAM), the imager/spectrometer onboard JUNO mission, mainly devoted to the study of Jupiter’s atmosphere, had the opportunity to acquire data of the Galilean satellites, including Io. JIRAM is composed of a slit spectrometer covering a range of wavelengths between 2 and 5 μm and an imager equipped with two filters, L and M, centered at 3.4 and 4.7 μm, respectively [1]. 

In this work, we mapped the Io hot spots by using JIRAM M filter images from orbits 7, 9, 10, 16, 17, 18, 20, 24, 25, 26, 27, 32, 33, with a spatial scale ranging from ∼ 48 up to ~150 km/pixel (Fig. 1), updating the work by [5]. For each orbit, we consider a set of images (referred to as “super images”) which contain the average radiance of several JIRAM contiguous observations. This approach minimizes the effects due to spurious pixels, reducing the detection of false hot spots [5].

JIRAM data cover almost the entire surface of Io, with a redundancy up to 43 super images per pixel in the northern and equatorial regions (Fig. 2), improving the observations of the polar areas. To identify Io hot spots, we first filtered each super image for emission angles > 75°. Then, since JIRAM data have been acquired at different incidence angles, including Io dayside, nightside, and eclipse (Fig. 1), to select the hot spots, we divided the images in three categories: day (i≤ 70°), dawn/dusk (70° < i < 90°) and night i≥ 90°. For each super image, we calculated the median value of the radiance for the dayside, nightside and dawn/dusk background. Hence, we considered as hot spots’ detection limit the radiance values larger than the median radiance for the night side, and median background radiance plus 0.003 for dawn/dusk and day side. 

We identified 242 hot spots, many of which had already been included in other databases (e. g. [6, 7, 8, 9]). Among the hot spots revealed by JIRAM, 24 have not been observed before, and half of these are located at the poles.  The comparison between our results and the last Io global heat flow power output map published by [8] suggests that the highest power heat flow hot spots are still active, indicating their activity lasts for decades or more, while a large part of the intermediate power heat flow hot spots are still present, as only 15 of them are not included in our map. We found the larger discrepancies in the lower heat flow hot spots, given that many of those listed as active by [8] have not been observed by JIRAM. 

The study of Io hot spots variation and distribution, is worthwhile in helping to constrain the interior models and the magma distribution in its subsurface. The Io hot spots map presented here is the most up-to-date one produced by remote sensing datasets. The future JIRAM higher spatial resolution observations will be fundamental to extend and confirm our results, better distinguish close hot spots and improve our overall knowledge of Io volcanic processes and evolution.

Figure 1: Example of Io JIRAM M filter images for the orbits JM 24 and 25.

Figure 2: JIRAM M filter data coverage of Io for JIRAM orbits 10, 11, 16, 17, 18, 20, 24, 25, 26, 27, 32, 33.

Acknowledgments

This work is supported by Agenzia Spaziale Italiana (ASI). JIRAM is funded by ASI contract 2016-353 23-H.0. 

References

[1] Peale, S. J.,  et al., 1979, Science, 203. [2] Davies et al., 2015, Icarus, 262. [3] de Kleer et al., 2019, The Astronomical Journal, 158. [4] Adriani et al., 2017, Space Science Review, 213. [5] Mura, A., et al., 2020, Icarus, 241. [6] Lopes and Spencer, Eds, 2007, Praxis-Springer. [7] Williams, D. A., et al., 2011, Icarus, 214. [8] Veeder, G. J., et al., 2015, Icarus, 245. [9] Cantrall, C., et al., 2018, Icarus, 312.

How to cite: Zambon, F., Mura, A., Rathbun, J., Lopes, R., Tosi, F., Sordini, R., Noschese, R., Adriani, A., Ciarniello, M., Filacchione, G., Grassi, D., Piccioni, G., Plainaki, C., Sindoni, G., Turrini, D., Brooks, S., Hansen-Koharcheck, C., and Bolton, S.: Io hot spots detection as revealed by JUNO/JIRAM data, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-691, https://doi.org/10.5194/epsc2022-691, 2022.

The Juno spacecraft’s polar orbit with periapses (perijove; PJ) within a few thousand kilometers of the 1-bar level has allowed for detailed observations of Jupiter’s thunderstorms from multiple instruments at unprecedented resolution.  Here, we detail the observations of a 2,500-km wide thunderstorm feature located in the North Equatorial Belt (at planetocentric latitude 9°N; Fig. 1) from the six channels of the Microwave Radiometer Instrument (MWR), from JunoCam’s RGB filters, from the Jovian Infrared Auroral Mapper’s (JIRAM) 5-micron band, and from supporting Earth-Based images taken during near the time of the 38^th perijove. Juno flew over one such thunderstorm complex at close range (~5,000 km) on 29 Nov. 2021 for the first time with a favorable alignment to observe such a feature at low emission angles. JunoCam and MWR observations were taken nearly simultaneously while JIRAM’s data was collected approximately 4.5 hours prior. 

Moist convection is widely thought to play a large role in transporting heat from Jupiter’s interior through the weather layer (here defined as 10 to 0.7 bar) and then to space. In the process, heat transport allows for moist convection, which powers thunderstorms and generates small-scale turbulence that, through the inverse-cascade mechanism, generates large-scale vortices and zonal jets.  Convective instability allows for strong updrafts that carry volatiles such as NH₃ and H₂O from the base of the water-cloud (and deeper) upwards to form cumulonimbus (CB) clouds.  The tops of these CB towers diverge outwards and are shaped by local winds to form an icy anvil cloud much as they do on Earth.

Lightning is a defining characteristic of CB clouds and the MWR instrument detected numerous flashes in and around the bright white feature with a storm-like morphology clearly observed by JunoCam. JIRAM’s M-band filter images clearly show the structure of the cloud tops, matching observations from JunoCam once the zonally-averaged motion over the 4.5-hour time separation is accounted for. Figure 2 is a JIRAM image with a noticeable dark ‘notch,’ which is where the optically thick storm clouds are located. Preliminary spectral analysis from JIRAM shows a slightly enhanced signal of H₂O and PH₃ near the anvil top but NH₃ ice is undetectable in these night-time JIRAM observations.

Gaseous NH₃ and H₂O are partially opaque to wavelengths sensed by the MWR instrument.  Each of the six channels of MWR have a sensitivity that peaks at different altitudes in the atmosphere, which allows us to sound the brightness temperature and the vertical structure from the cloud tops down to many tens of bars.  The brightness temperature is a combination of air temperature and humidity, and, at present, we are unable to deconvolve these two measurements. Nevertheless, sounding the brightness temperature provides information on the depth and structure of a tall atmospheric feature and we present brightness temperature maps for all six channels.

We observe that this particular thunderstorm complex is visible from the cloud tops (~0.7 bar) down to approximately the level of the water cloud. Below this level, the thunderstorm signal is no longer apparent, which indicates that any dry convective updraft carrying MWR opacity-inducing vapor is either not present, or its air temperature and humidity are combined in such a way to mask its presence perfectly. If this thunderstorm is a result of dry convection from below the base of the water cloud lifting moist air to the level of free convection (LFC) then the effect of the dry convection is to lift vapor already located around the base of the water-cloud level rather than bringing up significantly moist air from deep below the base of the water cloud, or otherwise a signal would be detected in the short wavelength channels of MWR (See Fig. 3 for a cloud-top MWR map).

The next several perijoves will feature an orientation for the MWR instrument that is conducive for low emission angle observations. Additionally, the latitude of perijove is slowly migrating northward and, if Juno does fly over new thunderstorms, we may have the opportunity to compare the vertical structure of multiple thunderstorms taken from different regions of the planet at high resolution from multiple instruments.

Figure 1: PJ38 Thunderstorm from JunoCam Image JNCE_2021333_38C00030_V01 (left) and close-up  (right: Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill)

Figure 2: Map-Projected Processed Close-Up Image of PJ38 Thunderstorm from JIRAM M-Band Image (Image Credit: NASA/JPL-Caltech/INAF-IAPS). Circle denotes location of optically thick storm clouds.

Figure 3: Map-Projected MWR Ch 6 Brightness Temperature

How to cite: Brueshaber, S., Orton, G., Zhang, Z., Oyafuso, F., Mura, A., Grassi, D., Eichstadt, G., Hansen, C., Fletcher, L., Mizumoto, S., Momary, T., Levin, S., and Bolton, S.: Dissecting Jupiter’s Thunderstorms: Results from JIRAM, JunoCam, MWR and Earth-Based Observations, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-733, https://doi.org/10.5194/epsc2022-733, 2022.

We present a discrete observation of diverse plasma populations and evidence of closed magnetic topology at Jupiter’s polar cap. Two distinct populations of protons are observed over Jupiter’s southern polar cap: a ~1 keV core population and ~1-300 keV dispersive conic population at 6-7 Jovian radii planetocentric distance. We find the 1 keV core protons are likely the seed population for the higher-energy dispersive conics. Transient wave-particle heating in a “pressure-cooker” process is likely responsible for this proton acceleration. The plasma characteristics and composition during this period show Jupiter's polar-most field lines can be topologically closed, with conjugate magnetic footpoints connected to both hemispheres. Finally, these observations demonstrate energetic protons can be accelerated into Jupiter's magnetotail via wave-particle coupling.

How to cite: Szalay, J., Clark, G., Livadiotis, G., McComas, D., Mitchell, D., Rankin, J., Sulaiman, A., Allegrini, F., Bagenal, F., Ebert, R., Gladstone, R., Kurth, B., Mauk, B., Valek, P., Wilson, R., and Bolton, S.: Closed Fluxtubes and Proton Conics in Jupiter’s Polar Cap, Europlanet Science Congress 2022, Granada, Spain, 18–23 Sep 2022, EPSC2022-741, https://doi.org/10.5194/epsc2022-741, 2022.