Defining scale thresholds for geomagnetic storms through statistics

Palacios, J.; Guerrero, Antonio José Moreno; Cid, C.; Sáiz, E.; Cerrato, Y.

doi:10.5194/nhess-2018-92

Cited by 6 publications

(4 citation statements)

References 11 publications

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“…Here, the effects can be demonstrated by the predicted XEO lightcurve with NRLMSISE-00 density profile for the changing solar activities index F 10.7 and geomagnetic activities index Ap. The values of the model lightcurves under the extreme solar activity and the very low solar activity (Licata et al, 2020), the severe geomagnetic storm and the quiet geomagnetic activity (Palacios et al, 2018) are calculated, respectively, as shown in Figure 13. The energy range of the lightcurves is from 2.5 keV to 6.0 keV.…”

Section: Results Testingmentioning

confidence: 99%

Measurement of vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

et al. 2022

Preprint

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Abstract. The X-ray Earth occultation sounding (XEOS) is an emerging method for measuring the neutral density in the lower thermosphere. In this paper, the X-ray Earth occultation (XEO) of the Crab Nebula is investigated by using the Insight-HXMT. The pointing observation data on the 30th September, 2018 recorded by the Low Energy X-ray telescope (LE) of Insight-HXMT are selected and analyzed. The extinction lightcurves and spectra during the X-ray Earth occultation process are extracted. A forward model for the XEO lightcurve is established and the theoretical observational signal for lightcurve is predicted. A Bayesian data analysis method is developed for the XEO lightcurve modeling and the atmospheric density retrieval. The posterior probability distribution of the model parameters is derived through the Markov Chain Monte Carlo (MCMC) algorithm with the NRLMSISE-00 model and the NRLMSIS 2.0 model as basis functions and the best-fit density profiles are retrieved respectively. It is found that in the altitude range of 105–200 km, the retrieved density profile is 88.8 % of the density of NRLMSISE-00 and 109.7 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 1.0–2.5 keV based on XEOS method. In the altitude range of 95–125 km, the retrieved density profile is 81.0 % of the density of NRLMSISE-00 and 92.3 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 2.5–6.0 keV based on XEOS method. In the altitude range of 85–110 km, the retrieved density profile is 87.7 % of the density of NRLMSISE-00 and 101.4 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 6.0–10.0 keV based on XEOS method. The measurements of density profiles are compared with the NRLMSISE-00/NRLMSIS 2.0 model simulations and the previous retrieval results with RXTE satellite. Finally, we find that the retrieved density profile from Insight-HXMT based on the NRLMSISE-00/NRLMSIS 2.0 models is qualitatively consistent with the previous retrieved results from RXTE. This study demonstrate that the XEOS from the X-ray astronomical satellite Insight-HXMT can provide an approach for the study of the upper atmosphere. The Insight-HXMT satellite can join the family of the XEOS. The Insight-HXMT satellite with other X-ray astronomical satellites in orbit can form a space observation network for XEOS in the future.

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Section: Results Testingmentioning

confidence: 99%

Measurement of vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Here, the effects can be demonstrated by the predicted XEO lightcurve with NRLMSISE-00 density profile for the changing solar activities index F 10.7 and geomagnetic activities index Ap. The values of the model lightcurves under extreme solar activity and very low solar activity (Licata et al, 2020), a severe geomagnetic storm and quiet geomagnetic activity (Palacios et al, 2018) are calculated, respectively, as shown in Figure 13. The energy range of the lightcurve in panel (a), panel (b) and panel (c) in Figure 13 is 1.0-2.5 keV, 2.5-6.0 keV, and 6.0-10.0 keV, respectively.…”

Section: Results Testingmentioning

confidence: 99%

Measurement of the vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

Yu¹,

Li²,

Li³

et al. 2022

Preprint

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The X-ray Earth occultation sounding (XEOS) is an emerging method for measuring the neutral density in the lower thermosphere. In this paper, the X-ray Earth occultation (XEO) of the Crab Nebula is investigated by using the Hard X-ray Modulation Telescope (Insight-HXMT). The pointing observation data on the 30th September, 2018 recorded by the Low Energy X-ray telescope (LE) of Insight-HXMT are selected and analyzed. The extinction lightcurves and spectra during the X-ray Earth occultation process are extracted. A forward model for the XEO lightcurve is established and the theoretical observational signal for lightcurve is predicted. The atmospheric density model is built with a scale factor to the commonly used MSIS density profile within a certain altitude range. A Bayesian data analysis method is developed for the XEO lightcurve modeling and the atmospheric density retrieval. The posterior probability distribution of the model parameters is derived through the Markov Chain Monte Carlo (MCMC) algorithm with the NRLMSISE-00 model and the NRLMSIS 2.0 model as basis functions and the best-fit density profiles are retrieved respectively. It is found that in the altitude range of 105-200 km, the retrieved density profile is 88.8% of the density of NRLMSISE-00 and 109.7% of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 1.0-2.5 keV based on XEOS method. In the altitude range of 95-125 km, the retrieved density profile is 81.0% of the density of NRLMSISE-00 and 92.3% of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 2.5-6.0 keV based on XEOS method. In the altitude range of 85-110 km, the retrieved density profile is 87.7% of the density of NRLMSISE-00 and 101.4% of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 6.0-10.0 keV based on XEOS method. Goodness-of-fit testing is carried out for the validation of the results.The measurements of density profiles are compared to the NRLMSISE-00/NRLMSIS 2.0 model simulations and the previous retrieval results with NASA's Rossi X-ray Timing Explorer (RXTE) satellite. For further confirmation, we also compare the measured density profile to the ones by a standard spectrum retrieval method with an iterative inversion technique. Finally, we find that the retrieved density profile from Insight-HXMT based on the NRLMSISE-00/NRLMSIS 2.0 models is qualitatively

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“…Given the classification by Palacios et al. (2018), a quiet‐minor event corresponds to an Ap index between 0 and 20 nT while indices from 30 to 50 nT corresponds to a moderate storm. The Ap index reaches values higher than 20 nT between 17 UT and 18 UT, and afterward the index starts to increase, indicating that the geomagnetic storm starts to develop.…”

Section: Methodsmentioning

confidence: 99%

Quantification of Representation Error in the Neutral Winds and Ion Drifts Using Data Assimilation

Hu,

López Rubio,

Chartier

et al. 2024

Space Weather

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In this work we quantify the representation error of the algorithm Estimating Model Parameters from Ionospheric Reverse Engineering (EMPIRE), which estimates global neutral winds and ion drifts given time‐varying plasma densities. SAMI3 (Sami3 is A Model of the Ionosphere) serves as the background climate model and pseudo‐measurements for the EMPIRE observation system. This configuration allows the data assimilation inputs to be self‐consistent between each other and with the validation data. The estimated neutral winds and ion drifts are compared to the Horizontal Wind Model (HWM14) and SAMI3 “truth.” For both the quiet period on 25 August 2018 and subs7equent storm on 26 August, the EMPIRE estimation of ion drifts is better at low‐to‐mid geomagnetic latitudes with mean error up to 20 m/s. For the high latitudes (poleward of ±60° magnetic), the mean errors exceed 50 m/s with variances up to 200 m/s, and the relative errors are higher than the “truth.” At latitudes of ±87°, the large errors are attributed to a boundary effect. However, the neutral wind mean errors peak at 20 m/s at mid‐latitudes (40°–60° magnetic), with larger uncertainties, then converge to 0 approaching higher latitudes. By conducting this study, we define a method for obtaining the representation error covariance for future use of EMPIRE with SAMI3 as background.

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Defining scale thresholds for geomagnetic storms through statistics

Cited by 6 publications

References 11 publications

Measurement of vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

Measurement of vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

Measurement of the vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

Quantification of Representation Error in the Neutral Winds and Ion Drifts Using Data Assimilation

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