The two solar flares diagnostics based on the soft X-ray emission recording

Savchenko, M. I.; Vatagin, P. V.; Lazutkov, V. P.; Skorodumov, D. V.; Kudryavtsev, I. V.; Charikov, Yuriy E.

doi:10.1016/j.spjpm.2017.09.007

Cited by 2 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The spectral energy density of solar flares is a complex function of flare plasma dynamics, with changing magnitude and spectral distribution over the duration of the flare. Flare spectroscopy is still an active area of research, with continued efforts underway to measure and model the time‐dependent spectrum (Chaimberlin et al, ; Fletcher et al, ; Jeffrey, ; Lin et al, ; Savchenko et al, ). We approximate the vacuum spectral energy density for a flare at a distance D away to be

U_{ν_{0}} false(t false) = \frac{U_{0} false(t false)}{4 π D^{2}} B false(u false)

with units of energy per unit area.…”

Section: The Physics Of X‐ray Flare Impact On the Lower Ionospherementioning

confidence: 99%

“…Therefore, we use an approximation for the X‐ray spectrum from solar flares

B false(u false) = \frac{15}{π^{4}} \frac{u^{3}}{e^{u} - 1},

which is the normalized Planck distribution. Use of this distribution allows for T to be assigned to the spectrum in the manner of temperature models for plasma thermal bremsstrahlung emission of X‐rays (Caspi & Lin, ; Jeffrey, ; Savchenko et al, ). This blackbody spectrum only approximates the the thermal spectrum of emissions from solar flare plasmas that are generally nonuniform in temperature.…”

Section: The Physics Of X‐ray Flare Impact On the Lower Ionospherementioning

confidence: 99%

See 1 more Smart Citation

A Parameterized Model of X‐Ray Solar Flare Effects on the Lower Ionosphere and HF Propagation

2019

View full text Add to dashboard Cite

We present a parameterized X-ray solar flare effects model relating the physics of radiation transport to the observable impact of solar flares on low-altitude ionospheric absorption of High Frequency (HF) signals. Tunable parameters of time-varying flare spectral energy density and characteristic flare temperature provide a novel capability to simulate HF experiments over a wide range of X-ray solar flare behavior. Results from our model are consistent with HF propagation data collected over a period of heightened solar flare activity during 5-7 September 2017, including M and X class solar flares. Our predictions and measurements are compared with results from D Region Absorption Prediction (Akmaev et al., 2010, https://www.ngdc.noaa.gov/stp/drap/DRAP-V-Report1.pdf) and the Wait Very Low Frequency (VLF)-driven model (Wait & Spies, 1964). Plain Language SummaryWe present a physics-based model for high-frequency (HF) signal absorption resulting from the effects of X-ray solar flares on the low-altitude ionosphere. Our model calculates the extent of ionization enhancement in the D region due to an X-ray flare and predicts the altitude-dependent change of electron density and consequent increase in HF signal absorption. We demonstrate that results from our model are consistent with ionosonde data collected during three solar flare events. This model provides a novel approach to analyzing the impact of X-ray solar flares on HF propagation and is complementary to the widely used empirical D Region Absorption Prediction and Wait models. Key Points:• We developed a physics-based model of HF absorption due to X-ray solar flare impact on the low-altitude ionosphere • Model results are consistent with ionosonde data collected during flare events on a 3-day experimental campaign • The model is a novel approach to X-ray flare impact on HF propagation, complementing existing empirical modelsCorrespondence to:

show abstract

U_{ν_{0}} false(t false) = \frac{U_{0} false(t false)}{4 π D^{2}} B false(u false)

with units of energy per unit area.…”

Section: The Physics Of X‐ray Flare Impact On the Lower Ionospherementioning

confidence: 99%

“…Therefore, we use an approximation for the X‐ray spectrum from solar flares

B false(u false) = \frac{15}{π^{4}} \frac{u^{3}}{e^{u} - 1},

Section: The Physics Of X‐ray Flare Impact On the Lower Ionospherementioning

confidence: 99%

A Parameterized Model of X‐Ray Solar Flare Effects on the Lower Ionosphere and HF Propagation

2019

View full text Add to dashboard Cite

show abstract

“…Pada kondisi stabil, matahari tidak melontarkan partikel panas yang dapat menyebabkan gangguan radiasi elektromagnetik. Tetapi ada suatu waktu aktifitas matahari meningkat karena pelepasan energi intens dari solar corona [13]. Jika peningkatan aktifitas matahari cukup tinggi maka fenomena tersebut disebut dengan solar flare.…”

Section: Efek Solar Flareunclassified

Fenomena Sporadic E Frekuensi 5.2 MHZ Pada Kondisi Solar Minimum Tahun 2019

Zakariyah

Dutono

Santoso

et al. 2020

klik

View full text Add to dashboard Cite

High Frequency (HF) Communication is very dependent on the condition of the ionosphere which changes conditions over time. 2019 is a year with minimum solar conditions marked by a lack of solar cold spots. This condition can cause interference with the propagation path of radio waves in the ionosphere. In this research, a report on HF wave propagation observations is presented using a retrospective method to determine the sporadic E intensity at minimum solar conditions. Data retrieval is done by beacon / sounding system between radio stations by using a low power signal processing software that is Weak Signal Propagation Report (WSPR). Observations were made by building 2 radio stations in Surabaya (7.30S, 112.78E) as transmitter and radio stations in Jombang (7.61S, 112.31E) as receiver. Observations were carried out for one year from November 2018 until October 2019. During the observation process, a frequency of 5.2 MHz is used and the results showed that there were several days that described a favorable phenomenon for HF communication at close range (below 500 km), namely Sporadic E. During the observation it was obtained 8 times the Sporadic E phenomenon that is quite long with a time span of occurrence between 1 hour to 3 hours. Overall observations show that in May to August is the time when most Sporadic E phenomena occur. So from this research, it can be concluded that the sporadic E phenomenon can still occur when the sun enters the minimum solar conditions.Keywords: HF, Solar Minimum, Ionospher, Sporadic E Komunikasi High Frequency (HF) sangat bergantung pada kondisi ionosfer yang mengalami perubahan kondisi dari waktu ke waktu. Tahun 2019 merupakan tahun dengan kondisi solar minimum yang ditandai dengan minimnya nilai titik dingin matahari. Kondisi ini dapat mengakibatkan gangguan pada jalur propagasi gelombang radio di lapisan ionosfer. Pada penelitian ini, disajikan laporan pengamatan propagasi gelombang HF menggunakan metode retrospektif untuk mengetahui intensitas sporadic E saat kondisi solar minimum. Pengambilan data dilakukan dengan sistem beacon / sounding antar stasiun radio dengan memanfaatkan software pengolahan sinyal daya rendah yaitu Weak Signal Propagation Report (WSPR). Pengamatan dilakukan dengan membangun 2 stasiun radio yang berada di Surabaya (7.30S, 112.78E) sebagai pemancar dan stasiun radio di Jombang (7.61S, 112.31E) sebagai penerima. Pengamatan dilakukan selama satu tahun dari bulan November 2018 sampai dengan bulan Oktober 2019. Pada proses pengamatan digunakan frekuensi 5.2 MHz dan hasilnya menunjukkan terdapat beberapa hari yang menggambarkan fenomena menguntungkan untuk komunikasi HF jarak dekat (dibawah 500 km) yaitu Sporadic E. Selama pengamatan telah didapatkan 8 kali fenomena Sporadic E yang cukup lama dengan rentang waktu kejadian antara 1 jam hingga 3 jam. Secara keseluruhan hasil pengamatan menunjukkan bahwa pada bulan Mei hingga bulan Agustus merupakan waktu paling banyak terjadinya fenomena Sporadic E. Sehingga dari penelitian ini dapat disimpulkan bahwa fenomena sporadic E masih bisa terjadi ketika matahari memasuki kondisi solar minimum.Kata kunci: HF, Solar Minimum, Ionosfer, Sporadic E

show abstract

The two solar flares diagnostics based on the soft X-ray emission recording

Cited by 2 publications

References 11 publications

A Parameterized Model of X‐Ray Solar Flare Effects on the Lower Ionosphere and HF Propagation

A Parameterized Model of X‐Ray Solar Flare Effects on the Lower Ionosphere and HF Propagation

Fenomena Sporadic E Frekuensi 5.2 MHZ Pada Kondisi Solar Minimum Tahun 2019

Contact Info

Product

Resources

About