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Abstract The ion temperature in Jupiter's middle magnetosphere has been known to stay constant (or even increase) as a function of radial distance from the planet. This suggests that there is a non‐adiabatic heating process occurring in this region. Efforts have been made to explain this heating with different turbulent heating models utilizing data from previous science missions to Jupiter (Ng et al., 2018,https://doi.org/10.1029/2018JA025345; 2022,https://doi.org/10.1029/2021GL096662; Saur, 2004,https://doi.org/10.1086/382588). Using the turbulent heating rate density calculated from the Juno spacecraft magnetometer and particle data based on a forward fitting model utilizing a kappa distribution (Wang, Bagenal, Wilson, Nerney, et al., 2024,https://doi.org/10.1029/2023JA032218; Wang et al., 2024b,https://doi.org/10.1029/2024JA033454), the thermal equilibrium ion temperature in Jupiter's middle magnetosphere is estimated using an advection temperature model. We find that the model is not sufficient to account for the – K ( keV) temperatures seen in the forward fits particle data, which is about an order of magnitude higher than previously reported in particle data surveys (Bagenal & Delamere, 2011,https://doi.org/10.1029/2010JA016294).more » « lessFree, publicly-accessible full text available July 1, 2027
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Abstract The Juno mission, in conjunction with past missions and Earth‐based observations, has provided a wealth of information on Jupiter's magnetosphere. This magnetosphere is governed by Jupiter's strong magnetic field, rapid 10‐hr rotation, and a significant internal plasma source, the volcanic moon Io. Jupiter's magnetodisc exhibits plasma temperatures that deviate strongly from adiabatic expectations, increasing by nearly two orders of magnitude between the Io plasma torus and ∼25 . The physical mechanisms responsible for this heating remain poorly understood, particularly in the middle magnetosphere where advective transport dominates. In this study, we use a global magnetohydrodynamic (MHD) simulation to investigate the processes controlling plasma temperature evolution. Fluid tracing and test particle simulations are performed to analyze radial transport and energization within the magnetodisc. Our results reproduce key features of the observed temperature profiles, including the pronounced increase beyond 10 , without the need for additional heating terms. We demonstrate that a combination of tail reconnection, adiabatic compression, and large‐scale radial and corotational transport can explain the simulated temperature profiles, providing insight into the mechanisms governing plasma heating in Jupiter's magnetodisc. These findings highlight the importance of global scale MHD processes in shaping the thermal structure of the middle magnetosphere and offer a framework for interpreting Juno observations in regions not directly observed.more » « lessFree, publicly-accessible full text available July 1, 2027
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Japanese Rhinoceros beetles (Trypoxylus dichotomous), known primarily for their large horns, are a classic example of ornate weaponry produced through sexual selection. The male beetle’s prominent horns are used in male-to-male combat for dominance and access to females. Observations in the lab and the field suggest that multiple forms of signaling are also involved in both the aggressive interactions and female mate choice. One such signal seems to be the songs created through male abdominal stridulation. Males perform both an alarm-style chirp (also seen in aggressive interactions) and rhythmic “purring” prior to copulation attempts. Several questions arise in relation to this behavior and its effect on mating outcomes: Is there a relationship between song characteristics and morphological characteristics? Can vibrations be transmitted through the surrounding substrate? Is there a relationship between song characteristics and courtship outcomes? To analyze these songs in the field, a Polytech VibroGo VG-200 laser vibrometer was used to measure the velocity of both the male’s elytra and surrounding tree bark during courtship. Vibrational amplitude and periodicity, corresponding location, beetle characteristics, and courtship details were collected. Male courtship song characteristics will be compared to morphological variables, as well as courtship outcomes. Substrate vibration transmission and attenuation will also be discussed.more » « less
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