A new climatological electron density model for supporting space weather services

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2021044 ◽

2021 ◽

Author(s):

M Mainul Hoque ◽

Norbert Jakowski ◽

Fabricio S. Prol

Keyword(s):

Electron Density ◽

Space Weather ◽

Peak Height ◽

Density Model ◽

Solar Irradiation ◽

Electron Content ◽

Total Electron ◽

In Situ Data ◽

Van Allen Probes

The ionosphere is the ionized part of the Earth atmosphere, ranging from about 60 km up to several Earth radii whereas the upper part above about 1000 km height up to the plasmapause is usually called the plasmasphere. We present a new three-dimensional electron density model aiming for supporting space weather services and mitigation of propagation errors for trans-ionospheric signals. The model is developed by superposing the Neustrelitz Plasmasphere Model (NPSM) to an ionosphere model composed of separate F and E-layer distributions. It uses the Neustrelitz TEC model (NTCM), Neustrelitz Peak Density Model (NPDM) and the Neustrelitz Peak Height Model (NPHM) for the total electron content (TEC), peak ionization and peak height information. These models describe the spatial and temporal variability of the key parameters as function of local time, geographic/geomagnetic location, solar irradiation and activity. The model is particularly developed to calculate the electron concentration at any given location and time in the ionosphere for trans-ionospheric applications and named as the Neustrelitz Electron Density Model (NEDM2020). A comprehensive validation study is conducted against electron density in-situ data from DMSP and Swarm, Van Allen Probes and ICON missions, and topside TEC data from COSMIC/FORMOSAT-3 mission, bottom side TEC data from TOPEX/Poseidon mission and ground-based TEC data from International GNSS Service (IGS) covering both high and low solar activity conditions. Additionally, the model performance is compared with the 3D electron density model NeQuick2. Our investigation shows that the NEDM2020 performs better than the NeQuick2 when compared with the in-situ data from Van Allen Probes and ICON satellites and TEC data from COSMIC and TOPEX/Poseidon missions. When compared with DMSP and IGS TEC data both NEDM2020 and NeQuick2 perform very similarly.

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Strong equatorial plasma bubble associated with prominent TEC enhancement observed at mid-latitude ionosphere under the quiescent condition

10.5194/egusphere-egu21-3832 ◽

2021 ◽

Author(s):

Fuqing Huang ◽

Jiuhou Lei ◽

Chao Xiong

Keyword(s):

Electron Density ◽

Electron Content ◽

Radio Waves ◽

Plasma Bubble ◽

Total Electron ◽

Middle Latitudes ◽

Multiple Observations ◽

Equatorial Plasma Bubbles ◽

Low Latitudes

Equatorial plasma bubbles (EPBs) are typically ionospheric irregularities that frequently occur at the low latitudes and equatorial regions, which can significantly affect the propagation of radio waves. In this study, we reported a unique strong EPB that happened at middle latitudes over the Asian sector during the quiescent period. The multiple observations including total electron content (TEC) from Beidou geostationary satellites and GPS, ionosondes, in-situ electron density from SWARM and meteor radar are used to explore the characteristic and mechanism of the observed EPB. The unique strong EPB was associated with great nighttime TEC/electron density enhancement at the middle latitudes, which moves toward eastward. The potential physical processes of the observed EPB are also discussed.

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New GGOS JWG3 on Improved understanding of space weather events and their monitoring

10.5194/egusphere-egu2020-20492 ◽

2020 ◽

Author(s):

Alberto Garcia-Rigo ◽

Benedikt Soja

Keyword(s):

Electron Density ◽

Space Weather ◽

International Association ◽

Real Data ◽

Weather Conditions ◽

Electron Content ◽

Vertical Total Electron Content ◽

Total Electron ◽

Weather Events ◽

Space Geodetic Techniques

Multiple space geodetic techniques are capable of measuring effects caused by space weather events. In particular, space weather events can cause ionospheric disturbances correlated with variations in the vertical total electron content (VTEC) or the electron density (Ne) of the ionosphere.In this regard and in the context of the new Focus Area on Geodetic Space Weather Research within IAG&#8217;s GGOS (International Association of Geodesy; Global Geodetic Observing System), the Joint Working Group 3 on Improved understanding of space weather events and their monitoring by satellite missions has been created as part of IAG Commission 4, Sub-Commission 4.3 to run for the next four years.Within JWG3, we expect investigating different approaches to monitor space weather events using the data from different space geodetic techniques and, in particular, combinations thereof. Simulations will be beneficial to identify the contribution of different techniques and prepare for the analysis of real data. Different strategies for the combination of data will also be investigated, in particular, the weighting of estimates from different techniques in order to increase the performance and reliability of the combined estimates. Furthermore, existing algorithms for the detection and prediction of space weather events will be explored and improved to the extent possible. Furthermore, the geodetic measurement of the ionospheric electron density will be complemented by direct observations from the Sun gathered from existing spacecraft, such as SOHO, ACE, SDO, Parker Solar Probe, among others. The combination and joint evaluation of multiple datasets with the measurements of space geodetic observation techniques (e.g. geodetic VLBI) is still a great challenge. In addition, other indications for solar activity - such as the F10.7 index on solar radio flux, SOLERA as EUV proxy or rate of Global Electron Content (dGEC)-, provide additional opportunities for comparisons and validation.Through these investigations, we will identify the key parameters useful to improve real-time/prediction of ionospheric/plasmaspheric VTEC, Ne estimates, as well as ionospheric perturbations, in case of extreme solar weather conditions. In general, we will gain a better understanding of space weather events and their effect on Earth&#8217;s atmosphere and near-Earth environment.

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Low-Earth-Orbit observations for space weather and space climate

10.5194/egusphere-egu2020-12209 ◽

2020 ◽

Author(s):

Irina Zakharenkova ◽

Iurii Cherniak ◽

Sergey Sokolovskiy ◽

William Schreiner ◽

Qian Wu ◽

...

Keyword(s):

Electron Density ◽

Plasma Density ◽

Space Weather ◽

Ionospheric Plasma ◽

Radio Occultation ◽

Satellite Orbit ◽

Electron Content ◽

Gps Measurements ◽

Total Electron ◽

Ionospheric Plasma Density

Many of the modern Low-Earth-Orbiting satellites are now equipped with dual-frequency GPS receivers for Radio Occultation (RO) and Precise Orbit Determination (POD). The space-borne GPS measurements can be successfully utilized for ionospheric climatology and space weather monitoring. The combination of GPS measurements, which include RO observations and POD measurements from the upward-looking GPS antenna, provides information about electron density distribution (profile) below the satellite orbit and an integrated Total Electron Content (TEC) above the satellite representing an important data source for electron density climatology above the F2 layer peak on a global scale. We demonstrate the advantages of using space-borne LEO GPS measurements, both RO and upward-looking, for Space Weather activity monitoring including specification of ionospheric plasma density structures at different altitudinal domains of the ionosphere in quiet and disturbed conditions. After the great success of the COSMIC-1 (Constellation Observing System for Meteorology, Ionosphere, and Climate) mission operating since 2006, the six COSMIC-2 satellites were launched into a 24 deg inclination orbit in June 2019. The COSMIC-2 scientific payloads with the advanced Tri-GNSS Radio-Occultation Receiver System provide multiple observation types including multi-GNSS TEC (limb and overhead), RO electron density profiles, amplitude/phase scintillation indices, in-situ ion densities and velocities. The COSMIC-2 advanced instruments allow detection of ionospheric plasma density structures of various scales, and the monitoring of high-rate amplitude and phase scintillations both above and below a satellite orbit. The COSMIC-2 multi-instrumental observations will contribute to a better understanding of the equatorial ionosphere morphology and future forecasting of ionospheric irregularities and radio wave scintillations that harmfully affect satellite-to-Earth communication and navigation systems. We present results of post-event analyses for severe space weather events demonstrating a great potential and contribution of the COSMIC-1/2 missions in combination with the ground-based GNSS receivers and other LEO missions like C/NOFS, DMSP, MetOp, TerraSAR-X, and Swarm for monitoring the space weather effects in the Earth&#8217;s ionosphere.

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IONOSPHERIC DISTURBANCES OVER EASTERN SIBERIA DURING APRIL 12–15, 2016 GEOMAGNETIC STORMS

Solnechno-Zemnaya Fizika ◽

10.12737/szf-61202007 ◽

2020 ◽

Vol 6 (1) ◽

pp. 75-85

Author(s):

Aleksandr Rubtsov ◽

Boris Maletckii ◽

Ekaterina Danilchuk ◽

Ekaterina Smotrova ◽

Aleksei Shelkov ◽

...

Keyword(s):

Electron Density ◽

High Speed ◽

Geomagnetic Storms ◽

Peak Height ◽

Negative Response ◽

Small Scale ◽

Electron Content ◽

Ionospheric Disturbances ◽

Total Electron ◽

Optical Instruments

We present the results of the complex study of ionospheric parameter variations during two geomagnetic storms, which occurred on April 12–15, 2016. The study is based on data from a set of radiophysical and optical instruments. Both the storms with no sudden commencement were generated by high-speed streams from a coronal hole. Despite the minor intensity of the storms (Dst ≥ –55 and –59 nT), we have revealed a distinct ionospheric response to these disturbances. A negative response of electron density and F2-layer critical frequency was observed during the main phase of both the storms. The amplitude of the negative response was higher for the second storm. The period of negative electron density deviations was accompanied by an increase in the peak height, as well as by the downward plasma drift in the evening and night hours, which is not typical of quiet conditions. We have also recorded sharp peaks in the AATR (Along Arc TEC Rate) index and in total electron content noise spikes on average 2–2.5 times. This indicates an intensification of small-scale ionospheric disturbances caused by disturbed geomagnetic conditions and high substorm activity.

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Plasmasphere and Topside Ionosphere Reconstruction using METOP Satellite Data during Geomagnetic Storms

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020076 ◽

2020 ◽

Author(s):

Fabricio dos Santos Prol ◽

Mainul Hoque ◽

Arthur Amaral Ferreira

Keyword(s):

Electron Density ◽

Space Weather ◽

Geomagnetic Storms ◽

Tomographic Reconstruction ◽

Satellite System ◽

Low Earth Orbit ◽

Topside Ionosphere ◽

Reconstruction Technique ◽

Electron Content ◽

Total Electron

As part of the space weather monitoring, the response of the ionosphere and plasmasphere to geomagnetic storms is typically under continuous supervision by operational services. Fortunately, Global Navigation Satellite System (GNSS) receivers on board low Earth orbit satellites provides a unique opportunity for developing image representations that can capture the global distribution of the electron density in the plasmasphere and topside ionosphere. Among the difficulties of plasmaspheric imaging based on GNSS measurements, the development of procedures to invert the Total Electron Content (TEC) into electron density distributions remains as a challenging task. In this study, a new tomographic reconstruction technique is presented to estimate the electron density from TEC data along the METOP (Meteorological Operational) satellites. The proposed method is evaluated during four geomagnetic storms to check the capabilities of the tomography for space weather monitoring. The investigation shows that the developed method can successfully capture and reconstruct well-known enhancement and decrease of electron density variabilities during storms. The comparison with in-situ electron densities has shown an improvement around 11% and a better description of plasma variabilities due to the storms compared to the background. Our study also reveals that the plasmasphere TEC contribution to ground-based TEC may vary 10 to 60% during geomagnetic storms, and the contribution tends to reduce during the storm-recovery phase

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

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2018002 ◽

2018 ◽

Vol 8 ◽

pp. A16 ◽

Cited By ~ 8

Author(s):

Norbert Jakowski ◽

Mohammed Mainul Hoque

Keyword(s):

Electron Density ◽

Space Weather ◽

Geomagnetic Field ◽

Wind Pressure ◽

External Parameter ◽

Electron Content ◽

Lower Altitude ◽

Total Electron ◽

Dependent Part ◽

Winter Anomaly

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.

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Ionospheric tomography by gradient-enhanced kriging with STEC measurements and ionosonde characteristics

Annales Geophysicae ◽

10.5194/angeo-34-999-2016 ◽

2016 ◽

Vol 34 (11) ◽

pp. 999-1010 ◽

Cited By ~ 4

Author(s):

David Minkwitz ◽

Karl Gerald van den Boogaart ◽

Tatjana Gerzen ◽

Mainul Hoque ◽

Manuel Hernández-Pajares

Keyword(s):

Electron Density ◽

A Priori ◽

Likelihood Estimation ◽

Peak Height ◽

Initial Guess ◽

Electron Content ◽

Covariance Model ◽

Spatial Covariance ◽

International Gnss Service ◽

Total Electron

Abstract. The estimation of the ionospheric electron density by kriging is based on the optimization of a parametric measurement covariance model. First, the extension of kriging with slant total electron content (STEC) measurements based on a spatial covariance to kriging with a spatial–temporal covariance model, assimilating STEC data of a sliding window, is presented. Secondly, a novel tomography approach by gradient-enhanced kriging (GEK) is developed. Beyond the ingestion of STEC measurements, GEK assimilates ionosonde characteristics, providing peak electron density measurements as well as gradient information. Both approaches deploy the 3-D electron density model NeQuick as a priori information and estimate the covariance parameter vector within a maximum likelihood estimation for the dedicated tomography time stamp. The methods are validated in the European region for two periods covering quiet and active ionospheric conditions. The kriging with spatial and spatial–temporal covariance model is analysed regarding its capability to reproduce STEC, differential STEC and foF2. Therefore, the estimates are compared to the NeQuick model results, the 2-D TEC maps of the International GNSS Service and the DLR's Ionospheric Monitoring and Prediction Center, and in the case of foF2 to two independent ionosonde stations. Moreover, simulated STEC and ionosonde measurements are used to investigate the electron density profiles estimated by the GEK in comparison to a kriging with STEC only. The results indicate a crucial improvement in the initial guess by the developed methods and point out the potential compensation for a bias in the peak height hmF2 by means of GEK.

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Regional representation of F2 Chapman parameters based on electron density profiles

Annales Geophysicae ◽

10.5194/angeo-31-2215-2013 ◽

2013 ◽

Vol 31 (12) ◽

pp. 2215-2227 ◽

Cited By ~ 16

Author(s):

M. Limberger ◽

W. Liang ◽

M. Schmidt ◽

D. Dettmering ◽

U. Hugentobler

Keyword(s):

Electron Density ◽

Real Data ◽

Peak Height ◽

Electron Content ◽

Density Profiles ◽

Total Electron ◽

Maximum Electron Density ◽

Spatio Temporal ◽

Electron Density Profiles ◽

Model Approach

Abstract. Understanding the physical processes within the ionosphere is a key requirement to improve and extend ionospheric modeling approaches. The determination of meaningful parameters to describe the vertical electron density distribution and how they are influenced by the solar activity is an important topic in ionospheric research. In this regard, the F2 layer of the ionosphere plays a key role as it contains the highest concentration of electrons and ions. In this contribution, the maximum electron density NmF2, peak height hmF2 and scale height HF2 of the F2 layer are determined by employing a model approach for regional applications realized by the combination of endpoint-interpolating polynomial B splines with an adapted physics-motivated Chapman layer. For this purpose, electron density profiles derived from ionospheric GPS radio occultation measurements of the satellite missions FORMOSAT-3/COSMIC, GRACE and CHAMP have been successfully exploited. Profiles contain electron density observations at discrete spots, in contrast to the commonly used integrated total electron content from GNSS, and therefore are highly sensitive to obtaining the required information of the vertical electron density structure. The spatio-temporal availability of profiles is indeed rather sparse, but the model approach meets all requirements to combine observation techniques implicating the mutual support of the measurements concerning accuracy, sensitivity and data resolution. For the model initialization and to bridge observation gaps, the International Reference Ionosphere 2007 is applied. Validations by means of simulations and selected real data scenarios show that this model approach has significant potential and the ability to yield reliable results.

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IONOSPHERIC DISTURBANCES OVER EASTERN SIBERIA DURING APRIL 12–15, 2016 GEOMAGNETIC STORMS

Solar-Terrestrial Physics ◽

10.12737/stp-61202007 ◽

2020 ◽

Vol 6 (1) ◽

pp. 60-68

Author(s):

Aleksandr Rubtsov ◽

Boris Maletckii ◽

Ekaterina Danilchuk ◽

Ekaterina Smotrova ◽

Aleksei Shelkov ◽

...

Keyword(s):

Electron Density ◽

High Speed ◽

Geomagnetic Storms ◽

Peak Height ◽

Negative Response ◽

Small Scale ◽

Electron Content ◽

Ionospheric Disturbances ◽

Total Electron ◽

Optical Instruments

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Analysis of Swarm Electric Field Data in View of Tsunami Events and related Earthquakes

10.5194/egusphere-egu2020-18876 ◽

2020 ◽

Author(s):

Wojciech Jarmolowski ◽

Pawel Wielgosz ◽

Anna Krypiak-Gregorczyk ◽

Beata Milanowska

Keyword(s):

Electric Field ◽

Electron Density ◽

Electron Content ◽

Langmuir Probes ◽

Time And Space ◽

Total Electron ◽

Swarm Satellites ◽

High Orbit ◽

Orbital Height

Three Swarm satellites are equipped with Langmuir Probes (LP) measuring in-situ electron density of Earth electric field and POD GNSS receivers determining topside total electron content (TEC) in the upper ionosphere. It is proved that different events on the Earth and in its atmopshere have their own impact on Earth electric field, and the earthquakes are in this group. Many strong earthquakes induce tsunamis, which are also suspected as contributing to the gravity waves having an impact on the ionospheric TEC. These reasons encourage to the study on the sensitivity of Swarm LP and POD GNSS data to the abovementioned phenomena. Referring to the sensitivity of TEC data derived from GNSS stations to Earthquakes, sensitivity of GNSS and LP data at around 500 km high orbit is analyzed here. A similar orbital height can be found in case of many LEO missions equipped at least with GNSS POD receivers, which makes Swarm especially interesting data acquisition platforms.The investigation of Swarm data in view of Tsunamis and earthquakes is difficult due to several factors. There are only three satellites, the two of which fly almost together, which gives in fact only two points of the survey. The orbital repetition period is long, which seriously limits the number of comparable observations in terms of the location and time of the day. Finally, the number of large earthquakes and tsunami events in time of Swarm science mission is low, and many Earthquakes do not coincide sufficiently with Swarm passes in time and space. All these factors, however, doesn&#8217;t exclude an opportunity of analyzing of Swarm data passes above the earthquakes of magnitude nearby 8, linked with the tsunamis reaching several decimeters.Swarm LP data is detrended and analyzed before the earthquakes and also during the earthquakes and resulting tsunami events. The GNSS POD topside TEC from Swarm is analyzed together as a background for LP data. In-situ electron density disturbances occurring during a pass close to the earthquake is compared to selected STEC measurements between LEO and GNSS satellites. Additionally absolute STEC values from selected nearby ground stations are analyzed in order to&#160; find existing correlations for detected disturbances in the electric and magnetic fields. All the observations are sparse in time and space, and therefore, leave some unanswered questions and uncertainties. However, several interesting perturbations over earthquake/tsunami events are observable in both Swarm LP data and GNSS TEC data.

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