• Title/Summary/Keyword: Sun:flare

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Quantitative estimation of the energy ux during an explosive chromospheric evaporation in a white light are kernel observed by Hinode, IRIS, SDO, and RHESSI

  • Lee, Kyoung-Sun;Imada, Shinsuke;Watanabe, Kyoko;Bamba, Yumi;Brooks, David H.
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.2
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    • pp.67.3-68
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    • 2016
  • An X1.6 flare occurred in AR 12192 on 2014 October 22 around 14:06 UT and was observed by Hinode, IRIS, SDO and RHESSI. We analyze a bright kernel which produces a white light flare (WLF) with continuum enhancement and a hard X-ray (HXR) peak. Taking advantage of the spectroscopic observations of IRIS and EIS, we measure the temporal variation of the plasma properties in the bright kernel in the chromosphere and corona. We found that explosive evaporation was observed when the WLF occurred, even though the intensity enhancement in hotter lines is quite weak. The temporal correlation of the WLF, HXR peak, and evaporation flows indicates that the WLF was produced by accelerated electrons. To understand the white light emission processes, we calculated the deposited energy flux from the non-thermal electrons observed by RHESSI and compared it to the dissipated energy estimated from the chromospheric lines (Mg II triplet) observed by IRIS. The deposited energy flux from the non-thermal electrons is about $3.1{\times}10^{10}erg\;cm^{-2}s^{-1}$ when we assume a cut-off energy of 20 keV. The estimated energy flux from the temperature changes in the chromosphere measured from the Mg II subordinate line is about $4.6-6.7{\times}10^9erg\;cm^{-2}s^{-1}$, 15 - 22 % of the deposited energy. By comparison of these estimated energy fluxes we conclude that the continuum enhancement was directly produced by the non-thermal electrons.

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Development of Radio Spectrum Monitor for HF Communication (단파 스펙트럼 수신 모니터링 시스템 개발)

  • Park, Sung Won;Kim, Young Yun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.9
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    • pp.821-827
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    • 2015
  • Electromagnetic waves which are emitted from the Sun due to solar flare explosion can cause failures in HF radio communications in the day-side area of the Earth, that is so-call as Radio Blackouts. The international scale representing the severity of the Radio Blackouts is determined by the solar X-ray flux which is measured by United States Geostationary Operational Environmental Satellite. However, the scale is not always applicable to HF communication users in the different area on the Earth, because the HF communication effects depend not only on the X-ray strength but also on the subsolar point location. To solve this problem, we developed a HF radio spectrum monitoring system utilizing a spectrum analyzer. This system conducts a real-time measure of the HF spectrum, and automatically calculates signal to noise ratios and the occurrences of the HF blackouts as comparing with the interference level which is described from the ITU recommendation.

Relationship Between Solar Proton Events and Corona Mass Ejection Over the Solar Cycle 23 (태양 주기 23 기간 동안 태양 고에너지 양성자 이벤트와 코로나 물질 방출 사이의 상관관계)

  • Hwang, Jung-A;Lee, Jae-Jin;Kim, Yeon-Han;Cho, Kyung-Suk;Kim, Rok-Sun;Moon, Yong-Jae;Park, Young-Deuk
    • Journal of Astronomy and Space Sciences
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    • v.26 no.4
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    • pp.479-486
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    • 2009
  • We studied the solar proton events (SPEs) associated with coronal mass ejections (CMEs) during the solar cycle 23 (1997-2006). Using 63 SPE dataset, we investigated the relationship among SPE, flare, and CME, and found that (1) SPE rise time and duration time depend on CME speed and the earthward direction parameter of the CME, and (2) the SPE peak intensity depends on CME speed and X-ray Flare intensity. While inspecting the relation between SPE peak intensity and the direction parameter, we found there are two groups: first group consists of large six SPEs (> 10,000 pfu at > 10 MeV proton channel of GOES satellite) and shows strong correlation (cc = 0.65) between SPE peak intensity and CME direction parameter. The second group has a weak intensity and shows poor correlation between SPE peak intensity and the direction parameter (cc = 0.01). By investigating characteristics of the first group, we found that all the SPEs are associated with very fast halo CME (> 1400km/s) and also they are mostly located at central region and within ${\pm}20^{\circ}$ latitude and ${\pm}30^{\circ}$ longitude strip.

The Comparion of Pregnancy Outcomes between GnRH Agonist and GnRH Antagonist Cycles in Women with Advanced Age (37세 이상의 환자에서 체외수정시술시 GnRH Agonist 주기와 GnRH Antagonist 주기의 비교 연구)

  • Park, Chan Woo;Cha, Sun Wha;Kim, Hae Suk;Kim, Hye Ok;Yang, Kwang Moon;Kim, Jin Young;Song, In Ok;Yoo, Keun Jae;Kang, Inn Soo;Koong, Mi Kyoung
    • Clinical and Experimental Reproductive Medicine
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    • v.32 no.3
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    • pp.261-268
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    • 2005
  • Objective: To compare the clinical results and pregnancy outcomes of in vitro fertilization (IVF) between GnRH antagonist cycles and GnRH agonist (GnRH-a) cycles including flare-up and long protocol in women with advanced age. Materials and Methods: Retrospective clinical study. From January 2001 to September 2003, IVF cycles of female patient 37 years over were included in this study. GnRH-a long protocol (62 cycles, 61 patients) and GnRH antagonist multi-dose flexible protocol (66 cycles, 51 patients) were compared with the control group of GnRH-a flare-up protocol (151 cycles, 138 patients). IVF cycles for non-obstructive azoospermia (NOA), endometriosis III, IV and polycystic ovarian syndrome (PCOS) were excluded in this study. Clinical results such as total gonadotropin dose, serum E2 on hCG administration, the number of retrieved oocytes and the pregnancy outcomes - clinical pregnancy rate (CPR), implantation rate (IR) and live birth rate (LBR) per embryo transfer - were compared. Results: There were significant differences in the total dose of gonadotropin (GnRH-a flare-up vs. GnRH-a long vs. GnRH-antagonist; 41.8 vs. 54.7 vs. 24.8), serum E2 on hCG administration (1787.2 vs. 1881.6 vs. 788.0), the numbers of retrieved oocytes (8.1 vs. 11.1 vs. 4.5) and endometrial thickness (9.1 vs. 10.4 vs. 8.0) which were significantly lower in GnRH-antagonist cycles. But pregnancy outcomes shows no significant differenced in CPR (25.0% vs. 35.8% vs. 24.5%), IR (11.7% vs. 12.3% vs. 10.1%) and LBR (15.8% vs. 28.3% vs. 15.1%) Conclusion: In women with advanced age, GnRH-antagonist cycles can result in comparable pregnancy outcomes to GnRH-a cycles including flare-up and long protocol. GnRH-a long protocol show higher CPR, IR and LBR than GnRH antagonist multi-dose flexible protocol and flare-up protocol without significant differences.

TELESCOPE CONTROL AND DATA ANALYSIS SOFTWARES FOR THE SOFT (태양 플레어 망원경의 제어 및 자료 분석 무른모)

  • Moon, Yong-Jae;Yoon, So-Yoon;Park, Young-Deuk;Jang, Be-Ho
    • Publications of The Korean Astronomical Society
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    • v.12 no.1
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    • pp.47-62
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    • 1997
  • In this paper we present a newly improved telescope control software and a newly developed data analysis software package for effective use of the Solar Flare Telescope(SOFT) The telescope control software permits us to make not only auto tacking of the SOFT, but also quantitative measurement of the solar irradiation, allowing us to provide weather monitorings. In addition we introduce an IDL widget software package for both monochromatioc (MONO version) and polarimetric data (VMG version) analysis. The MONO version is capable of loading FITS files, changing colors and contrast, image processing, displaying plots, and saving displayed plots by selected formats The VMG version, on the other hand provides a calibration of polarimetric data and plots of reduced vector magnetic fields.

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The Case Report of Soyangin Yangdokbalban (陽毒發斑) (형방사백산(荊防瀉白散)을 활용한 소양인 양독발반(陽毒發斑) 치험 1례)

  • Park, Geun-Hee;Kim, Oh-Young;Park, Hye-Sun
    • The Journal of Korean Medicine
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    • v.32 no.4
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    • pp.159-166
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    • 2011
  • Objectives: This study reports using Hyungbangsabaksan to cure Soyangin Yangdokbalban (陽毒發斑) appealing Systemic Allergic Contact Dermatitis. Methods: After diagnosing the patient showing Papuloerythematous with no blisters in the body as a Soyangin Yangdokbalban (陽毒發斑), we prescribed the patient with Hyungbangsabak-san. We compared the condition of the patient before and after medication with photo shots. Results: After treatment, Papuloerythematous which was seen with the naked eye disappeared and various skin symptoms such as itching and warmth in the flare area also improved. Conclusions: After treatment, the symptoms of the patient who after eating lacquer chicken showed improvement.

Origin of the Multiple Type II Solar Radio Bursts Observed on December 31 2007

  • Cho, Kyung-Suk;Bong, Su-Chan;Kim, Yeon-Han;Kwon, Ryun-Young;Park, Geun-Seok;Moon, Yong-Jae;Park, Young-Deuk
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.37.1-37.1
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    • 2009
  • Solar type II radio burst is regarded as a signature of coronal shock. However its association with coronal mass ejections (CMEs)-driven shock and/or flare blast waves remains controversial. On December 31 2007, SOHO/LASCO and STEREO/COR observed a CME that occurred on the east limb of the Sun. Meanwhile, two type II bursts were observed sequently by KASI/E-Callisto and the Culgoora radio observatory during the CME apparence time. In this study, we estimate kinematics of the two coronal shocks from dynamic spectrum of the multiple type II bursts and compare with the kinematics of the CME derived from the space observations. An origin of the multiple type II bursts is inspected and discussed briefly.

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DRAG EFFECT OF KOMPSAT-1 DURING STRONG SOLAR AND GEOMAGNETIC ACTIVITY (강한 태양 및 지자기 활동 기간 중에 아리랑 위성 1호(KOMPSAT-1)의 궤도 변화)

  • Park, J.;Moon, Y.J.;Kim, K.H.;Cho, K.S.;Kim, H.D.;Kim, Y.H.;Park, Y.D.;Yi, Y.
    • Journal of Astronomy and Space Sciences
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    • v.24 no.2
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    • pp.125-134
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    • 2007
  • In this paper, we analyze the orbital variation of the Korea Multi-Purpose SATellite-1(KOMPSAT-1) in a strong space environment due to satellite drag by solar and geomagnetic activities. The satellite drag usually occurs slowly, but becomes serious satellite drag when the space environment suddenly changes via strong solar activity like a big flare eruption or coronal mass ejections(CMEs). Especially, KOMPSAT-1 as a low earth orbit satellite has a distinct increase of the drag acceleration by the variations of atmospheric friction. We consider factors of solar activity to have serious effects on the satellite drag from two points of view. One is an effect of high energy radiation when the flare occurs in the Sun. This radiation heats and expands the upper atmosphere of the Earth as the number of neutral particles is suddenly increased. The other is an effect of Joule and precipitating particle heating caused by current of plasma and precipitation of particles during geomagnetic storms by CMEs. It also affects the density of neutral particles by heating the upper atmo-sphere. We investigate the satellite drag acceleration associated with the two factors for five events selected based on solar and geomagnetic data from 2001 to 2002. The major results can be summarized as follows. First, the drag acceleration started to increase with solar EUV radiation with the best cross-correlation (r = 0.92) for 1 day delayed F10.7. Second, the drag acceleration and Dst index have similar patterns when the geomagnetic storm is dominant and the drag acceleration abruptly increases during the strong geomagnetic storm. Third, the background variation of the drag accelerations is governed by the solar radiation, while their short term (less than a day) variations is governed by geomagnetic storms.

IONOSPHERIC EFFECTS ON THE RADIO COMMUNICATION (전파통신에서의 전리층 역할)

  • PYO YOO SURN;CHO KYOUNGSEOK;LEE DONG-HUN;KIM EUNHWA
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc2
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    • pp.21-25
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    • 2000
  • The ionosphere, the atmosphere of the earth ionized by solar radiations, has been strongly varied with solar activity. The ionosphere varies with the solar cycle, the seasons, the latitudes and during any given day. Radio wave propagation through or in the ionosphere is affected by ionospheric condition so that one needs to consider its effects on operating communication systems normally. For examples, sporadic E may form at any time. It occurs at altitudes between 90 to 140 km (in the E region), and may be spread over a large area or be confined to a small region. Sometimes the sporadic E layer works as a mirror so that the communication signal does not reach the receiver. And radiation from the Sun during large solar flares causes increased ionization in the D region which results in greater absorption of HF radio waves. This phenomenon is called short wave fade-outs. If the flare is large enough, the whole of the HF spectrum can be rendered unusable for a period of time. Due to events on the Sun, sometimes the Earth's magnetic field becomes disturbed. The geomagnetic field and the ionosphere are linked in complex ways and a disturbance in the geomagnetic field can often cause a disturbance in the F region of the ionosphere. An enhancement will not usually concern the HF communicator, but the depression may cause frequencies normally used for communication to be too high with the result that the wave penetrates the ionosphere. Ionospheric storms can occur throughout the solar cycle and are related to coronal mass ejections (CMEs) and coronal holes on the Sun. Except the above mentioned phenomena, there are a lot of things to affect the radio communication. Nowadays, radio technique for probing the terrestrial ionosphere has a tendency to use satellite system such as GPS. To get more accurate information about the variation of the ionospheric electron density, a TEC measurement system is necessary so RRL will operate the system in the near future.

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