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Intermittent energy dissipation by turbulent reconnection
Eastwood, J. P.; André, M.; Vaivads, A. +5 more
Magnetic reconnection—the process responsible for many explosive phenomena in both nature and laboratory—is efficient at dissipating magnetic energy into particle energy. To date, exactly how this dissipation happens remains unclear, owing to the scarcity of multipoint measurements of the "diffusion region" at the sub-ion scale. Here we report suc…
Methodology to create a new total solar irradiance record: Making a composite out of multiple data records
Schöll, Micha; Dudok de Wit, Thierry; Fröhlich, Claus +1 more
Many observational records critically rely on our ability to merge different (and not necessarily overlapping) observations into a single composite. We provide a novel and fully traceable approach for doing so, which relies on a multiscale maximum likelihood estimator. This approach overcomes the problem of data gaps in a natural way and uses data…
Explaining the rolling-pin distribution of suprathermal electrons behind dipolarization fronts
Cao, J. B.; Xu, Y.; Fu, H. S. +2 more
The rolling-pin distribution of suprathermal electrons (40-200 keV), showing electron pitch angles primarily at 0°, 90°, and 180°, has recently been reported behind dipolarization fronts (DFs) both in observations and simulations. The formation of such type of distribution, however, has been unclear so far. In this study, we present an observation…
Response of Jupiter's auroras to conditions in the interplanetary medium as measured by the Hubble Space Telescope and Juno
Wilson, R. J.; Kurth, W. S.; McComas, D. J. +24 more
We present the first comparison of Jupiter's auroral morphology with an extended, continuous, and complete set of near-Jupiter interplanetary data, revealing the response of Jupiter's auroras to the interplanetary conditions. We show that for ∼1-3 days following compression region onset, the planet's main emission brightened. A duskside poleward r…
Kinetic Alfvén wave explanation of the Hall fields in magnetic reconnection
Lavraud, Benoit; Wang, Chi; Dai, Lei +4 more
Magnetic reconnection is initiated in a small diffusion region but can drive global-scale dynamics in Earth's magnetosphere, solar flares, and astrophysical systems. Understanding the processes at work in the diffusion region remains a main challenge in space plasma physics. Recent in situ observations from Magnetospheric Multiscale and Time Histo…
Titan's Topography and Shape at the End of the Cassini Mission
Hayes, A. G.; Iess, L.; Stiles, B. W. +6 more
With the conclusion of the Cassini mission, we present an updated topographic map of Titan, including all the available altimetry, SARtopo, and stereophotogrammetry topographic data sets available from the mission. We use radial basis functions to interpolate the sparse data set, which covers only ∼9% of Titan's global area. The most notable updat…
Energy conversion at dipolarization fronts
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +2 more
We use multispacecraft observations by Cluster in the Earth's magnetotail and 3-D particle-in-cell simulations to investigate conversion of electromagnetic energy at the front of a fast plasma jet. We find that the major energy conversion is happening in the Earth (laboratory) frame, where the electromagnetic energy is being transferred from the e…
Topographic Constraints on the Evolution and Connectivity of Titan's Lacustrine Basins
Lorenz, R. D.; Hayes, A. G.; Kirk, R. L. +11 more
The topography provided by altimetry, synthetic aperture radar-topography, and stereo radargrammetry has opened new doors for Titan research by allowing for quantitative analysis of morphologic form. Using altimetry measurements, we show that Titan's Maria are consistent with an equipotential surface but that several filled lakes are found to be h…
Rapid Pitch Angle Evolution of Suprathermal Electrons Behind Dipolarization Fronts
Daly, P. W.; Cao, J. B.; Xu, Y. +4 more
The pitch angle distribution (PAD) of suprathermal electrons can have both spatial and temporal evolution in the magnetotail and theoretically can be an indication of electron energization/cooling processes there. So far, the spatial evolution of PAD has been well studied, leaving the temporal evolution as an open question. To reveal the temporal …
Global observations of magnetospheric high-m poloidal waves during the 22 June 2015 magnetic storm
Russell, C. T.; Anderson, B. J.; Nakamura, R. +12 more
We report global observations of high-m poloidal waves during the recovery phase of the 22 June 2015 magnetic storm from a constellation of widely spaced satellites of five missions including Magnetospheric Multiscale (MMS), Van Allen Probes, Time History of Events and Macroscale Interactions during Substorm (THEMIS), Cluster, and Geostationary Op…