<p>Chorus waves can cause the loss of energetic electrons in the Earth's radiation belts and ring current via pitch-angle diffusion. To quantify the effect of chorus waves on energetic electrons, we calculated the bounce-averaged quasi-linear diffusion coefficients. In this study, using these diffusion coefficients, we parameterize the lifetime of the electrons with an energy range from 1 keV to 2 MeV. In each magnetic local time (MLT), we calculate the lifetime for each energy and L-shell using two different methods. By applying polynomial fits, we parameterize the electron lifetime as a function of L-shell and electron kinetic energy (Ek) in each MLT and geomagnetic activity (Kp). The parameterized electron lifetimes show a strong functional dependence on L-shell and electron energy. During storm time, the lifetimes for higher energy (> 100 keV) electrons range from hours to days in the heart of the radiation belts. In contrast, the lifetimes for electrons with lower energy (< 100 keV) range from minutes to hours. This parameterization of electron lifetime is convenient for inclusion in simulations in the inner magnetosphere. </p>

<p>An update on our project aiming to provide space weather predictions that will be initiated from observations on the Sun and to predict radiation in space and its effects on satellite infrastructure. Real-time predictions and a historical record of the dynamics of the cold plasma density and ring current allow for evaluation of surface charging, and predictions of the relativistic electron fluxes will allow for the evaluation of deep dielectric charging. The project aims to provide a 1-2 day probabilistic forecast of ring current and radiation belt environments, which will allow satellite operators to respond to predictions that present a significant threat. As a backbone of the project, we use the most advanced codes that currently exist and adapt existing codes to perform ensemble simulations and uncertainty quantifications. This project includes a number of innovative tools including data assimilation and uncertainty quantification, new models of near-Earth electromagnetic wave environment, ensemble predictions of solar wind parameters at L1, and data-driven forecast of the geomagnetic Kp index and plasma density. The developed codes may be used in the future for realistic modelling of extreme space weather events. The PAGER consortium is made up of leading academic and industry experts in space weather research, space physics, empirical data modelling, and space environment effects on spacecraft from Europe and the US.</p>

<p><span>The Earth’s magnetic field traps charged particles which are transported longitudinally around Earth, generating a near-circular </span><span>current, known as the ring current. While the ring current has been measured on the ground and space for many decades, the </span><span>enhancement of the ring current during geomagnetic storms is still not well understood, due to many processes contributing to </span><span>its dynamics on different time scales. The low energy part of the ring current of 10-50 keV </span>is responsible for surface charging effects on spacecraft, potentially causing satellite anomalies.</p><p><span>Here, we show that existing ring cur</span><span>rent models systematically overestimate the in-situ satellite measurements of </span><span>the Earth’s night side electron ring current during geomagnetic storms.</span> <span>By </span><span>analyzing electron drift trajectories during the storm onset, we show that this </span><span>systematic overestimation of flux can be explained through a missing loss pro</span><span>cess which operates in the pre-midnight sector.</span> <span>Quantifying this loss reveals </span><span>that the theoretical upper limit of strong diffusion has to be reached in a broad </span><span>region of space in order to reproduce the observed flux. We include this miss</span><span>ing loss process and show that predictions of electron flux can be significantly </span><span>improved. Identifying missing loss processes in ring current models is vital to </span><span>accurately predict storm time dynamics and the associated hazards, that result </span><span>from a delicate balance of source and loss processes.</span></p>

<p>Ring current particles affect the terrestrial magnetic field configuration, altering particle trajectories, as well as presenting a surface charging hazard for satellites. These particles can act as a seed population for the electron radiation belts and generate plasma waves. Accurately describing ring current dynamics is crucial to understand the near-Earth plasma environment. Here we report on our first results of the expansion of the Versatile Electron Radiation Belt (VERB) code to model ring current proton dynamics (proVERB). We perform sensitivity studies for the four dimensional grid, considering the grid resolution necessary to resolve proton dynamics. Analysing the banana shaped orbits for ring current protons shows that the azimuthal grid resolution is comparable to the electron grid, while the resolution in the radial grid has to be significantly enhanced. Loss mechanisms of charge exchange and Coulomb collisions, thought to be largely responsible for the decay of the ring current during the recovery phase of a storm, are included in proVERB. We present our first simulation results and compare them to observations from the Van Allen probes HOPE and MagEIS instruments. By retaining and omitting charge exchange and Coulomb collisions in our simulations, we study the role of these loss processes on the ring current evolution during active periods.</p>