Predictable and unpredictable ionospheric disturbances during St. Patrick's Day magnetic storms of 2013 and 2015 and on 8–9 March 2008

Дмитриев, А. В.; Suvorova, A. V.; Клименко, М. В.; Клименко, В. В.; Ratovsky, Konstantin; Рахматулин, Р. А.; Parkhomov, V. A.

doi:10.1002/2016ja023260

Cited by 63 publications

(36 citation statements)

References 37 publications

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“…This is possibly partly attributed to TEC prediction at the four stations in the South Atlantic Anomaly (SAA) region (see Figure S3), which is not considered by Shim, Rastätter, et al (). In the SAA region, TEC enhancement occurred due to the energy input from the outer radiation belts (Dmitriev et al, ); however, most models do not predict the large enhancement of TEC (e.g., dTEC[%] at Port Stanley) as we mentioned above.…”

Section: Performance Of the Models In Predictions Of Fof2 And Vtec Onmentioning

confidence: 78%

Validation of Ionospheric Specifications During Geomagnetic Storms: TEC and foF2 During the 2013 March Storm Event

et al. 2018

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To address challenges of assessing space weather modeling capabilities, the Community Coordinated Modeling Center is leading a newly established International Forum for Space Weather Modeling Capabilities Assessment. This paper presents preliminary results of validation of modeled foF2 (F 2 layer critical frequency) and TEC (total electron content) during the first selected 2013 March storm event (17 March 2013). In this study, we used eight ionospheric models ranging from empirical to physics-based, coupled ionosphere-thermosphere and data assimilation models. The quantities we considered are TEC and foF2 changes and percentage changes compared to quiet time background, and the maximum and minimum percentage changes. In addition, we considered normalized percentage changes of TEC. We compared the modeled quantities with ground-based observations of vertical Global Navigation Satellite System TEC (provided by Massachusetts Institute of Technology Haystack Observatory) and foF2 data (provided by Global Ionospheric Radio Observatory) at the 12 locations selected in middle latitudes of the American and European-African longitude sectors. To quantitatively evaluate the models' performance, we calculated skill scores including correlation coefficient, root-mean square error (RMSE), ratio of the modeled to observed maximum percentage changes (yield), and timing error. Our study indicates that average RMSEs of foF2 range from about 1 MHz to 1.5 MHz. The average RMSEs of TEC are between~5 and~10 TECU (1 TEC Unit = 10 16 el/m 2 ). dfoF2[%] RMSEs are between 15% and 25%, which is smaller than RMSE of dTEC[%] ranging from 30% to 60%. The performance of the models varies with the location and metrics considered.To address the needs and challenge of assessment of our current knowledge about space weather effects on IT system and current state of IT modeling capabilities, the Community Coordinated Modeling Center (CCMC) has been supporting community-wide model validation projects, including Coupling, Energetics and Dynamics of Atmospheric Regions (CEDAR) and Geospace Environment Modeling (GEM)-CEDAR modeling challenges. The CCMC initiated the CEDAR electrodynamics thermosphere ionosphere challenge in 2009 focusing on the evaluation of basic IT system parameters modeled, such as electron and neutral densities, the ionospheric F 2 layer peak electron density (NmF2) and peak height (hmF2), and vertical drift (Shim Key Points: • foF2/TEC and foF2/TEC changes during a storm predicted by eight ionosphere models were compared with GIRO foF2 and GPS TEC measurements • Skill scores (e.g., correlation coefficient, RMSE, yield, and timing error) were calculated • Model performance strongly depends on the quantities considered, the type of metrics used, and the location considered Supporting Information: • Supporting Information S1 Correspondence to: J. S. Shim, jasoon.shim@nasa.gov Citation: Shim, J. S., Tsagouri, I., Goncharenko, L., Rastaetter, L., Kuznetsova, M., Bilitza, D., et al. (2018). Validation of ionospheric specifications du...

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Section: Performance Of the Models In Predictions Of Fof2 And Vtec Onmentioning

confidence: 78%

Validation of Ionospheric Specifications During Geomagnetic Storms: TEC and foF2 During the 2013 March Storm Event

et al. 2018

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“…We noted that the behavior of FEE is similar to keV energy electrons in the inner RB. Likewise, occurrence and intensity of the FEE events does not depend on storm strength (e.g., Dmitriev et al, ). The similarity of dynamical properties of the inner RB electrons and FEE in the low/medium energy range is also consistent with the conjecture that enhanced FEE fluxes are of the inner RB origin.…”

Section: Introductionmentioning

confidence: 99%

“…Note that mirror points of the quasi‐trapped energetic electrons in the FEE events are located at ionospheric heights (<1,000 km), which means that these electrons may manifest themselves through ionizing effect on the upper atmosphere gas. A meaningful assessment that great‐FEE enhancements indeed are able to affect the topside ionosphere at low latitudes was provided in a number of papers (Dmitriev et al, ; Suvorova, Tsai, & Dmitriev, ; Suvorova et al, , , , ). The quasi‐trapped electrons mirror at heights of 300–600 km in a region located ~10°–30° off the equator.…”

Section: Introductionmentioning

confidence: 99%

“…From comparison with the ionospheric model results, it was shown that the ionizing effect is able to contribute >50% of the positive ionospheric storms and is most likely responsible for their long durations (Suvorova et al, ). During major storms, the FEE‐related ionization can be in excess of 20 TECU (total electron content units, 1 TECU = 10 16 el m −2 ) at day and night (Dmitriev et al, ; Suvorova et al, , ). During recurrent storms and moderate geomagnetic disturbances caused by interplanetary shocks, less intense FEE fluxes result in smaller total electron content increases (< 15 TECU) (Suvorova et al, , ).…”

Section: Introductionmentioning

confidence: 99%

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Flux Enhancements of > 30 keV Electrons at Low Drift Shells L < 1.2 During Last Solar Cycles

Suvorova

2017

JGR Space Physics

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We present results of statistical analysis of enhancements of >30 keV electrons observed by the NOAA/POES satellites during solar cycles 23 and 24 (1998–2016) at low drift shells L < 1.2, so‐called forbidden zone. We collected 1,750 days (~25% of the total time) when fluxes of the forbidden energetic electrons (FEE) exceeded 103 (cm2 s sr)−1. We found 530 days, when FEE fluxes reached high intensity from 104 up to 107 (cm2 s sr)−1. It was found that the FEE enhancements were observed mostly often at the declining phases and solar minimum. More than 85% of the events occurred under fast solar wind (V > 450 km/s), high substorm activity (AL >150 nT), and enhanced interplanetary electric field perturbations (VδB > 1.5 mV/m). The FEE occurrence rate peaks around the local midnight. We have also found a quite unexpected annual variation of the FEE occurrence rate with a pronounced maximum from May to September, a minor peak in December–January, and minima at the equinoxes. The May–September peak, persisting at different solar cycle phases, was assumed to originate from high conductivity in the auroral ionosphere, which is controlled by the dipole tilt angle and provides better conditions for penetration of electric field perturbations into the inner magnetosphere. This allows explanation of the shape and amplitude of annual variation in the FEE occurrence rate from the convolution of the solar wind driver with the penetration conditions.

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“…Here, we summarize the main characteristics of the electron injections into the very low L-shells 101 from several papers Suvorova et al, 2013;Suvorova, 102 2017;Dmitriev et al, 2017). The quasi-trapped energetic electron population in the forbidden 103 zone, referred to as forbidden energetic electrons (FEE), can be characterized as transient with 104 highly variable fluxes.…”

Section: Introduction 28mentioning

confidence: 99%

Energetic electron enhancements under radiation belt (L

Suvorova

Дмитриев

Parkhomov

2019

Preprint

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11An unusual event of deep injections of >30 keV electrons from the radiation belt to low L shells 12 (L <1.2) in midnight-dawn sector occurred during nonstorm conditions on August 1, 2008. Using 13 THEMIS observations in front of the bow shock, we found transient foreshock conditions and 14 rotational discontinuities passing the subsolar region at that time. These conditions resulted in 15 generation of fast magnetosheath plasma jets and penetration of the magnetosheath plasma into 16 the magnetosphere as were observed by the THEMIS probes after approaching the magnetopause. 17The magnetosphere responded to variations in the IMF orientation by magnetic field 18 perturbations. Magnetic records at ground-magnetometers of INTERMAGNET provided 19 evidence of a global geomagnetic response in the form of geomagnetic pulses from the equator 20 to middle latitudes. The earliest response was found at low latitudes in the predawn sector. We 21 propose a scenario of possible association between dynamical foreshock in the subsolar region, 22 magnetosheath plasma jets and the deepest injections of the >30 keV electrons at L < 1.2 at the 23 midnight-dawn sector. 24 25 penetration is consistent with convection of plasma sheet protons, and deep electron penetration 54 suggests the existence of a local time localized mechanism. Turner et al. (2015) studied energetic 55 electron flux enhancements at L < 6 and also suggested that the deep injections at L < 4 (inside 56 the plasmasphere) may result from a different mechanism than injections observed at higher L 57 shells (outside the plasmasphere). They hypothesized that the mechanism could be related to 58 wave activity in the Pi2 frequency range which usually serves as an indicator of substorm 59 activity. Overall, dynamics of the tens to hundred keV electrons at low L-shells is very different 60 from dynamics of both protons and electrons at higher L-shells and also in higher energy range. 61

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Predictable and unpredictable ionospheric disturbances during St. Patrick's Day magnetic storms of 2013 and 2015 and on 8–9 March 2008

Cited by 63 publications

References 37 publications

Validation of Ionospheric Specifications During Geomagnetic Storms: TEC and foF2 During the 2013 March Storm Event

Validation of Ionospheric Specifications During Geomagnetic Storms: TEC and foF2 During the 2013 March Storm Event

Flux Enhancements of > 30 keV Electrons at Low Drift Shells L < 1.2 During Last Solar Cycles

Energetic electron enhancements under radiation belt (L

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