A multifluid version of the Lyon‐Fedder‐Mobarry global simulation model has been used to investigate effects outflowing ionospheric O + on magnetosphere‐ionosphere system. To quantify these effects, we specify number density, upward parallel velocity, and temperature outflow in a limited area low‐altitude boundary representing projection cusp, cleft, low‐latitude layer. baseline without is compared with simulations range fluxes initial velocities. In cases high fluxes, it shown that...

It is widely accepted that the ionosphere an important source of ions in magnetosphere and until recently this population has largely been neglected from many global simulations. In study, a causally regulated cusp O + outflow added to multifluid version Lyon‐Fedder‐Mobarry (LFM) simulation. The algorithm uses empirical relationships regulate flux with further conditioning isolate spatially dynamic cusp. impact on magnetosphere‐ionosphere (MI) system investigated for moderate storm 31 August...

Abstract Electron acceleration by dispersive scale Alfvén waves at Jupiter is investigated using a Gyrofluid‐Kinetic‐Electron model. Specifically, the simulations consider propagation of an wave perturbation from center Io plasma torus to high‐latitude regions that are consistent with recent Juno satellite observations (e.g., Allegrini et al., 2017, https://doi.org/10.1002/2017GL073180 ; Mauk, 2017a, https://doi.org/10.1038/nature23648 2017b, https://doi.org/10.1002/2016GL072286 Szalay 2018,...

Abstract The Juno spacecraft had previously observed intense high frequency wave emission, broadband electron and energetic proton energy distributions within magnetic flux tubes connected to Io, Europa, Ganymede, their wakes. In this work, we report consistent enhancements in <46 keV fluxes during these satellite tube transit intervals. We find enhanced at discrete energies linearly separated velocity for Io wake tubes, both Europa Ganymede tubes. propose be a result of resonances...

Abstract Banded energy distributions of H + , O ++ S +++ and or ions between 100 eV ∼20 keV are consistently observed in Jupiter's magnetosphere mapping to M‐shells M = 10–20. The bands correspond flux enhancements at similar speeds for different ion species, providing the first evidence simultaneous bounce‐resonant acceleration multiple species magnetosphere. Ion occur energies which bounce frequencies trapped matched integer harmonics System‐III corotation frequency. observations highlight...

Abstract Recent Cluster satellite observations have illustrated that substorm auroral bead formation and currents are associated with the presence of dispersive scale standing Alfvén waves, which also known as kinetic field line resonances (KFLRs) or eigenmodes. In this work, properties these waves further examined using simulations a gyrofluid‐kinetic electron model in conjunction at mid‐latitudes Defense Meteorological Satellite Program high‐latitudes. These incorporate, for first time,...

Abstract A new 2‐D self‐consistent hybrid gyrofluid‐kinetic electron model in dipolar coordinates is presented and used to simulate dispersive‐scale Alfvén wave pulse propagation from the equator ionosphere along an L = 10 magnetic field line. The extension of MHD‐kinetic that incorporates ion Larmor radius corrections via kinetic fluid Cheng Johnson (1999). It found consideration a realistic temperature ratio decreases time plasma sheet by several seconds relative ρ i =0 case (which also...

The generation of Alfvénic Poynting flux in the central plasma sheet and its polar distribution at low altitude are studied using three dimensional global simulations solar wind‐magnetosphere‐ionosphere interaction. A 24‐hour event simulation (4–5 Feb 2004) driven by wind interplanetary magnetic field data reproduces morphology measured Polar satellite, including dawn‐dusk asymmetry. Controlled show that asymmetry is regulated spatial variation ionospheric conductance. disappears when...

Abstract In this study, a 2‐D self‐consistent hybrid gyrofluid‐kinetic electron model is used to investigate Alfvén wave propagation along dipolar magnetic field lines for range of ion temperature ratios. The focus the investigation on understanding role these effects trapping in kinetic waves sourced plasma sheet and contributing overall energization at ionosphere. This work also builds our previous effort by considering similar system limit fixed initial parallel current, rather than...

Abstract Ability to quantify variations in magnetic field topology and density within Jupiter's magnetosphere is an important step understanding the overall structure dynamics. The Juno spacecraft has provided a rich data set dawnside magnetosphere. recent Grid Agnostic MHD for Extended Research Applications (GAMERA) global simulation study by Zhang et al. (2021, https://doi.org/10.1126/sciadv.abd1204 ) showed highly structured plasmadisc with closed lines mapped between outer dawn‐tail...

Abstract Juno performed two close flybys of Io and found enhanced field‐aligned proton fluxes are absorbed by Io. These protons at mass input rates comparable to previous estimates for hydrogen losses from Io, hence Jupiter is likely the source The conditions necessary this occur are: (a) formation Alfvén waves (b) wave‐particle coupling energize protons, (c) anti‐planetward transport ions due magnetic mirror force and/or parallel acceleration, (d) strong sub‐Alfvénic interaction slowing...

We have determined the black carbon concentration in three sets of ice core samples from GISP2 (Greenland Ice Sheet Project 2) core. The major peaks between 320 and 330 A.D. correlate well with ammonium dips electrical conductivity measurements (ECM), which allows us to identify extensive forest fires this time period. average during decade is found be 2.1 µg per 1 kg snow melt water. current (1989 1990) site shows an about 2.0 µ/kg suggesting that rate deposition at Greenland 1989–1990 was...

A hybrid MHD kinetic‐electron model in dipolar coordinates is used to simulate the upward current region of a geomagnetic Field Line Resonance (FLR) system for realistic ambient electron temperature keV. It found that mirror force effects result potential drops sufficient accelerate electrons energies excess keV support field aligned currents on order 0.5 μ A/m 2 . The wave energy dissipated this acceleration would completely damp an undriven FLR with equatorial width R E within two resonance cycles.

Abstract Juno satellite observations have illustrated substantial examples of broadband electron energization up to 10 5 –10 6 eV levels. In order explain these observations, we use a hybrid gyrofluid kinetic‐electron model in an untilted dipolar topology illustrate high levels weak current conditions by inertial Alfvén waves close the Jupiter ionosphere for ambient plasma densities and magnetic field perturbations inferred from observations. The key is extremely low evident which...

Abstract A simple approximation has been developed for the infrared emittance of clouds composed water spheres based on absorption and polynomial to Mie efficiency. The expression IR is obtained in a analytical form as function liquid content two size distribution parameters, namely, effective radius variance. suitable numerical weather prediction, climate modeling, radiative transfer calculations. accuracy, when compared exact calculation integration over distribution, within few percent,...

The linear wave equation (sixth order in space and time) the corresponding dispersion relation is derived for Hall magnetohydrodynamic (MHD) waves including electron inertial finite Larmor radius effects together with several limiting cases a homogeneous plasma. We contrast these limits solution of full terms normal (k⊥,k∥) diagrams to clearly illustrate range applicability individual approximations. analyze solutions all three MHD modes (fast, slow, Alfvén), particular attention given how...

Abstract Observations in kinetic scale field line resonances, or eigenmodes of the geomagnetic field, reveal highly field‐aligned plateaued electron distributions. By combining observations from Van Allen Probes and Cluster spacecraft with a hybrid gyrofluid simulation we show how these distributions arise nonlocal self‐consistent interaction electrons wavefield. This is manifested as trapping standing wave potential. The process operates along most qualitatively accounts for near equatorial...

The ion temperature of the magnetosphere Jupiter derived from Galileo PLS data was observed to increase by about an order magnitude 10 40 radii. This suggests presence heating sources that counteract adiabatic cooling effect expanding plasma. There have been different attempts explaining this phenomena, including a magnetohydrodynamic (MHD) turbulent model which is based on flux tube diffusion [Saur, Astrophys. J. Lett., 602, L137, 2004]. We explore alternate advection, similar models...

Abstract Using measurements from the Van Allen Probes, we show that field‐aligned fluxes of electrons energized by dispersive Alfvén waves (DAWs) are prominent in inner magnetosphere during active conditions. These have preferentially anisotropies 1.2 to > 2 at energies ranging tens electron volts several kiloelectron (keV), with largest values being coincident magnetic field dipolarizations. Comparisons reveal DAW energy densities and Poynting strongly correlated precipitating also O +...

Abstract One of the grand challenge problems giant planet magnetospheres is issue nonadiabatic plasma heating. Simple turbulent heating models consider energy cascade rate from one scale to another where density based on perpendicular magnetic fluctuations counterpropagating Alfvén waves. Analytical expressions turbulence theory for have yielded promising results observed ion at Jupiter and Saturn. Here, we compare using hybrid simulations Kelvin–Helmholtz instability analytical estimates in...

Abstract Using a combination of Juno magnetometer and plasma data, we show evidence Alfvénic turbulence within the mid‐to‐high latitude magnetosphere with sufficient conditions to trigger auroral particle acceleration. We analyze 12 events that, in agreement theoretical results, are found be dissipative at electron inertial scale. Furthermore, these contain significant Poynting flux range ∼0.8–20 mW/m 2 ionospheric altitudes. This is generate emissions. confirm that such incompressible,...

Atmospheric black carbon concentrations have been measured in air and cloud water samples collected over southern Nova Scotia, Canada, during the North Atlantic Regional Experiment. The average atmospheric concentration found continental masses is 0.23±0.04 μg/ m 3 compared with 0.03±0.01 for maritime air. 1‐ to 3‐km layer are higher than those below 1 km, suggesting that most of not local origin. About 9% was form an internal mixture inside droplets. content about 40 μg/kg. non‐sea‐salt SO...

A two-dimensional hybrid magnetohydrodynamic-kinetic electron model in dipolar coordinates is used to study the case of a fundamental mode toroidal field line resonance (FLR) centered on an L=10 closed magnetic line. The initialized via perturbation azimuthal shear Alfvén velocity so that only upward aligned currents (corresponding downwelling electrons) are present at ionospheric boundaries during first half wave period. It found acceleration electrons carry can be significant sink energy...

Abstract The Juno spacecraft in a polar orbit around Jupiter has observed broadband electron energization signatures at high latitudes (Mauk et al., 2017, https://doi.org/10.1038/nature23648 ). We investigate the origin of this by simulating propagation dispersive Alfvén waves from Io plasma torus to latitudes. These may be triggered mechanisms such as moon‐magnetosphere interaction or inflows radial transport. build on initial hybrid gyrofluid‐kinetic simulation Damiano al. (2019,...