A new electron density model of the plasmasphere for operational applications and services

Abstract

The Earth's plasmasphere contributes essentially to total electron content (TEC) measurements from ground or satellite platforms. Furthermore, as an integral part of space weather, associated plasmaspheric phenomena must be addressed in conjunction with ionosphere weather monitoring by operational space weather services. For supporting space weather services and mitigation of propagation errors in Global Navigation Satellite Systems (GNSS) applications we have developed the empirical Neustrelitz plasmasphere model (NPSM). The model consists of an upper L shell dependent part and a lower altitude dependent part, both described by specific exponential decays. Here the McIllwain parameter L defines the geomagnetic field lines in a centered dipole model for the geomagnetic field. The coefficients of the developed approaches are successfully fitted to numerous electron density data derived from dual frequency GPS measurements on-board the CHAMP satellite mission from 2000 to 2005. The data are utilized for fitting up to the L shell L = 3 because a previous validation has shown a good agreement with IMAGE/RPI measurements up to this value. Using the solar radio flux index F10.7 as the only external parameter, the operation of the model is robust, with 40 coefficients fast and sufficiently accurate to be used as a background model for estimating TEC or electron density profiles in near real time GNSS applications and services. In addition to this, the model approach is sensitive to ionospheric coupling resulting in anomalies such as the Nighttime Winter Anomaly and the related Mid-Summer Nighttime Anomaly and even shows a slight plasmasphere compression of the dayside plasmasphere due to solar wind pressure. Modelled electron density and TEC values agree with estimates reported in the literature in similar cases.

Modeling Stable Auroral Red (SAR) Arcs at Geomagnetic Conjugate Points: Implications for Hemispheric Asymmetries in Heat Fluxes

“…Numerically, fluxtube contents were similar to nighttime ionospheric total electron content in a column of 1‐cm 2 cross section below 1,000 km (typically a few × 10 12 e − /cm 2 ). More recent studies based on non‐whistler methods are consistent with such prior work (Gonzalez‐Casado et al, ; Jakowski & Hoque, ; Lee et al, ). One of the earliest findings about plasmaspheric fluxtube contents is that they have a pronounced seasonal dependence.…”

Estimation of Spatial Gradients and Temporal Variations of the Total Electron Content Using Ground‐Based GNSS Measurements

“…Recently, an empirical global plasmasphere model has been added to the Neustrelitz model family. This is called the Neustrelitz Plasmasphere Model (Jakowski & Hoque, ) and is used to estimate the topside ionosphere and plasmaspheric density distribution. NEDM is composed of the ionosphere key parameter models Neustrelitz TEC Model, Neustrelitz Peak Density Model, and Neustrelitz Peak Height Model only driven by the solar radio flux index F10.7 that describes the solar activity level.…”

Multi‐Instrument Characterization of Magnetospheric Cold Plasma Dynamics in the June 22, 2015 Geomagnetic Storm

“…Another important aspect in the space weather context is the contribution of the plasmasphere (the region of cold and dense plasma encircling the Earth and approximately corotating with it) to the Total Electron Content (TEC) of the ionosphere. Plasmasphere density variations may then cause Global Navigation Satellite System (GNSS) inaccuracies and communications problems (Jakowski & Hoque, 2018).The most dramatic changes in plasma density and in its spatial distribution occur during geomagnetic storms. In particular, during events of southward turning of the interplanetary magnetic field (IMF), the enhanced dawn-dusk convection electric field may significantly erode the nightside plasmasphere (e.g., Goldstein et al, 2003), bringing its boundary (the plasmapause) from the typical distance of 4-5 Earth radii (R E ) up to ∼2 R E for the most extreme events (e.g., Chi et al, 2000).…”