Relative importance of solar X-rays below 10 Å and pulsed HF radiowave absorption at 2.132 MHz frequency over Delhi under solar flare conditions

1984 ◽  
Vol 4 (6) ◽  
pp. 139-142
Author(s):  
A.C. Balachandra Swamy ◽  
V.K. Rajeev ◽  
J. Zachariah ◽  
C.S.G.K. Setty
Keyword(s):  
Solar Flare ◽  
X Rays ◽  
Relative Importance ◽  
Radiowave Absorption

Localization of the solar flare SF900610 in X-rays with the WATCH instrument of the GRANAT observatory

2002 ◽  
Vol 28 (12) ◽  
pp. 853-856
Author(s):  
O. V. Terekhov ◽  
A. G. Kuzmin ◽  
A. V. Shevchenko ◽  
S. Yu. Sazonov ◽  
R. A. Sunyaev ◽  
...  
Keyword(s):  
Solar Flare ◽  
X Rays

scholarly journals RESPON TEC IONOSFER DI ATAS BANDUNG DAN MANADO TERKAIT FLARE SINAR-X MATAHARI KELAS M5.1 DAN M7.9 TAHUN 2015 (IONOSPHERIC TEC RESPONSE OVER BANDUNG DAN MANADO ASSOCIATED WITH M5.1 AND M7.9 CLASSES OF SOLAR FLARE XRAYS IN 2015)

2018 ◽  
Vol 14 (2) ◽  
pp. 111
Author(s):  
Sri Ekawati
Keyword(s):  
Time Delay ◽  
Solar Flare ◽  
Electron Density ◽  
Total Electron Content ◽  
Geomagnetic Latitude ◽  
Ionospheric Scintillation ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
X Rays ◽  
Total Electron

The solar flare is potential to cause sudden increase of the electron density in the ionosphere,particularly in D layer, known as Sudden Ionospheric Disturbances (SID). This increase of electron density occurs not only in the ionospheric D layer but also in the ionospheric E and F layers. Total Electron Content (TEC) measured by GPS is the total number of electrons from D to F layer. The aim of this research is to study the effect of solar flare x-rays, greater than M5 class in 2015, on ionospheric TEC over Bandung and Manado. This paper presents the preliminary result of ionospheric TEC response on solar flare occurrence over Indonesia. The ionospheric TEC data is derived from GPS Ionospheric Scintillation and TEC Monitor (GISTM) receiver at Bandung (-6.90o S;107.6o E geomagnetic latitude 16.54o S) and Manado (1.48o N; 124.85o E geomagnetic latitude 7.7o S). The solar x-rays flares classes analyzed where M5.1 on 10 March 2015 and M7.9 on 25 June 2015. Slant TEC (STEC) values where calculated to obtain Vertical TEC (VTEC) and the Differential of the VTEC (DVTEC) per PRN satellite for further analysis. The results showed that immediately after the flare, there where sudden enhancement of the VTEC and the DVTEC (over Bandung and Manado) at the same time. The time delay of ionospheric TEC response on M5.1 flare was approximately 2 minutes, then the VTEC increased by 0.5 TECU and the DVTEC rose sharply by 0.5 – 0.6 TECU/minutes. Moreover, the time delay after the M7.9 flare was approximately 11 minutes, then the VTEC increased by 1 TECU and the DVTEC rose sharply by 0.6 – 0.9 TECU/minutes. ABSTRAK Flare matahari berpotensi meningkatkan kerapatan elektron ionosfer secara mendadak, khususnya di lapisan D, yang dikenal sebagai Sudden Ionospheric Disturbances (SID). Peningkatan kerapatan elektron tersebut terjadi tidak hanya di lapisan D, tetapi juga di lapisan E dan F ionosfer. Total Electron Content (TEC) dari GPS merupakan jumlah banyaknya elektron total dari lapisan D sampai lapisan F. Penelitian ini bertujuan mengetahui efek flare, yang lebih besar dari kelas M5 tahun 2015, terhadap TEC ionosfer di atas Bandung dan Manado. Makalah ini merupakan hasil awal dari respon TEC ionosfer terhadap fenomena flare di atas Indonesia. Data TEC ionosfer diperoleh dari penerima GPS Ionospheric Scintillation and TEC Monitor (GISTM) di Bandung (-6,90o S; 107,60o E lintang geomagnet 16,54o LS) dan Manado (1,48oLU;124,85oBT lintang geomagnet 7,7o LS) dikaitkan dengan kejadian flare kelas M5.1 pada tanggal 10 Maret 2015 dan kelas M7.9 pada tanggal 25 Juni 2015. Nilai Slant TEC (STEC) dihitung untuk memperoleh nilai Vertical TEC (VTEC), kemudian nilai Differential of VTEC (DVTEC) per PRN satelit diperoleh untuk analisis selanjutnya. Hasil menunjukkan segera setelah terjadi flare, terjadi peningkatan VTEC dan DVTEC (di atas Bandung dan Manado) secara mendadak pada waktu yang sama. Waktu tunda dari respon TEC ionosfer setelah terjadi flare M5.1 adalah sekitar 2 menit, kemudian VTEC meningkat sebesar 0,5 TECU dan DVTEC meningkat secara tajam sebesar 0,5 – 0,6 TECU/menit. Sedangkan, waktu tunda setelah terjadi flare M7.9 adalah 11 menit, kemudian VTEC meningkat sebesar 1 TECU dan DVTEC meningkat secara tajam sebesar 0,6 – 0,9 TECU/menit.

scholarly journals DIFFERENTIAL SENSITIVITY OF PROPHASE POLLEN TUBE CHROMOSOMES TO X-RAYS AND ULTRAVIOLET RADIATION

1943 ◽  
Vol 26 (5) ◽  
pp. 485-494 ◽  
Author(s):  
C. P. Swanson
Keyword(s):  
Nucleic Acid ◽  
Pollen Tube ◽  
Differential Sensitivity ◽  
X Rays ◽  
Relative Importance ◽  
Generative Nucleus ◽  
Acid Cycle ◽  
X Ray ◽  
Total Absence ◽  
The Matrix

1. Through use of the pollen tube technique it has been possible to study the sensitivity of prophase stages to x-rays and ultraviolet, and to correlate the varying sensitivity with changes in the generative nucleus of Tradescantia. 2. Sensitivity to ultraviolet decreases from the 2 hour stage until at 11 hours after germination there is no further production of breaks. The 0 and 1 hour stages show a decreased sensitivity over the 2 hour stage but it has been suggested that this is not due to a decreased sensitivity but to shielding by the pollen wall. 3. Sensitivity to x-rays rises to a peak at the 4 hour stage, but then subsides until no breaks are realized (at a dose of 370.8 r) after the 10 hour stage. In this respect the effects of x-rays and ultraviolet are similar. Each type of x-ray break shows its own individual trend. 4. Correlation of x-ray breaks with changes in the generative nucleus indicates that the important events determining the sensitivity of the chromosomes to breakage are the uptake of water at the time of germination and the movement involved in spiralization. The total absence of breaks after the 11 hour stage is not understood. 5. The changing sensitivity to ultraviolet may depend on any one or all of three factors: (a) the nucleic acid cycle, (b) changes in the matrix, and (c) the number of subdivisions in the chromosome. These are discussed although their relative importance is not known.

Soft X-rays in the 00:18 UT solar flare on April 22, 1994

2000 ◽  
Vol 25 (5-6) ◽  
pp. 405-406 ◽  
Author(s):  
G.E. Kocharov ◽  
Yu.E. Charikov ◽  
V.P. Lazutkov ◽  
G.A. Matveev ◽  
Yu.N. Nitsora ◽  
...  
Keyword(s):  
Solar Flare ◽  
X Rays

On the Spatial Distribution of Hard X‐Rays from Solar Flare Loops

1999 ◽  
Vol 527 (2) ◽  
pp. 945-957 ◽  
Author(s):  
Vahe Petrosian ◽  
Timothy Q. Donaghy
Keyword(s):  
Spatial Distribution ◽  
Solar Flare ◽  
X Rays ◽  
Flare Loops

scholarly journals Electrons and X-Ray Emission of Solar Flares

1990 ◽  
Vol 142 ◽  
pp. 409-413
Author(s):  
V. G. Kurt
Keyword(s):  
Solar Activity ◽  
Statistical Analysis ◽  
Solar Flare ◽  
Frequency Dependence ◽  
Power Law ◽  
Solar Flares ◽  
X Rays ◽  
Fast Electrons ◽  
X Ray ◽  
Flare Frequency

A statistical analysis of solar flare X-rays and interplanetary particle fluxes, measured onboard VENERA-13, 14 Spacecraft, was performed. The correlation of fluences for different manifestations of solar flares is strong, especially for fast electrons and hard and soft X-ray emissions. Frequency dependence on fluence value ϵi for practically all Kinds of solar flare emission can be described by power law ν (ϵ > ϵO) ∼ ϵ−0.45±0.15 which does not change significantly with solar activity. For different Hα flare importances the values of ϵi were obtained. It is proposed that appearance of certain energy flare frequency is strongly dependent on some scale factor.

scholarly journals Forecasting Solar Energetic Particle (SEP) events with Flare X-ray peak ratios

2018 ◽  
Vol 8 ◽  
pp. A47 ◽  
Author(s):  
Stephen W. Kahler ◽  
Alan. G. Ling
Keyword(s):  
Solar Flare ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Western Hemisphere ◽  
X Rays ◽  
X Ray ◽  
Forecasting Methods ◽  
Versus Peak

Solar flare X-ray peak fluxes and fluences in the 0.1–0.8 nm band are often used in models to forecast solar energetic particle (SEP) events. Garcia (2004) [Forecasting methods for occurrence and magnitude of proton storms with solar soft X rays, Space Weather, 2, S02002, 2004] used ratios of the 0.05–0.4 and 0.1–0.8 nm bands of the X-ray instrument on the GOES spacecraft to plot inferred peak flare temperatures versus peak 0.1–0.8 nm fluxes for flares from 1988 to 2002. Flares associated with E > 10 MeV SEP events of >10 proton flux units (pfu) had statistically lower peak temperatures than those without SEP events and therefore offered a possible empirical forecasting tool for SEP events. We review the soft and hard X-ray flare spectral variations as SEP event forecast tools and repeat Garcia’s work for the period 1998–2016, comparing both the peak ratios and the ratios of the preceding 0.05–0.4 nm peak fluxes to the later 0.1–0.8 nm peak fluxes of flares >M3 to the occurrence of associated SEP events. We divide the events into eastern and western hemisphere sources and compare both small (1.2–10 pfu) and large (≥300 pfu) SEP events with those of >10 pfu. In the western hemisphere X-ray peak ratios are statistically lower for >10 pfu SEP events than for non-SEP events and are even lower for the large (>300 pfu) events. The small SEP events, however, are not distinguished from the non-SEP events. We discuss the possible connections between the flare X-ray peak ratios and associated coronal mass ejections that are presumed to be the sources of the SEPs.

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