Al-Mustansiriyah Journal of Science ISSN: 1814-635X (print), ISSN:2521-3520 (online) Volume 32, Issue 2, 2021 DOI: http://doi.org/10.23851/mjs.v32i2.984 58 Copyright © 2021 Al-Mustansiriyah Journal of Science. This work is licensed under a Creative Commons Attribution Noncommercial 4.0 International License. Research Article Open Access X-Ray Solar Flares Observed and Detected by the New Very-Low- Frequency Receiver in Nasiriyah City, South of Iraq Habeeb Allawi 1* , Moataz Jasim 2 , Kareem Abdulameer Difar 3 1 Ministry of Higher Education and Scientific Research/Directorate of Scholarships and Cultural Relations, Baghdad, IRAQ 2 Ministry of Education, Baghdad, IRAQ 3 Ministry of Higher Education and Scientific Research, Baghdad, IRAQ *Correspondent email: habeeballawi@gmail.com ArticleInfo ABSTRACT Received 31/12/2020 Accepted 10/02/2021 Published 13/05/2021 A receiver station was installed at Nasiriyah (Dhi Qar University - Faculty of Sciences) to receive very low frequency (VLF) radio signals from transmitters around the world. VLF waves are excellent probes of the sudden ionospheric disturbance (SID); they detect varying properties of the D layer presented as a lower region of the ionosphere when these waves propagate through the Earth-Ionosphere Waveguide. This study describes the set-up of our station system and it demonstrates its ability to detect sudden ionospheric disturbances caused by solar flares in May, June, July, August, and September 2017. We found out that the monitoring station is working successfully to receive FLV signals, and to detect sudden ionospheric disturbances. We detected 17 events resulting from solar flare C-class, 8 events from M-class, and 3 events from X-class that caused an increase in the received FLV amplitude. KEYWORDS: Solar flares, Very low frequency, Sudden Ionospheric Disturbance. خلصة ال تركيب محطة تمستقبال الجامعة ذي قار( لناصرية في ا- )علومية ال كلستلم لرات إشات الراديويةلموجا ا التردد ذات المنخفض جدا(VLF) . موجاتلعالمل حول الرسا من أجهزة اVLF ونيف اليغلضطراب ال ممتازة لحقيقات هي ت لمفاجئ ا(SID) لطبقةائص متباينة ل ؛ لقد اكتشفوا خصD ذهليونوسفير عندما تنتشر هخفضة من ا المقدمة كمنطقة من الموجييلت عبر الدللموجا اكتشاف وتوضح قدرته على ا محطتنا نظامذه الدراسة تكوينير. تصف هرض واليونوسفل ل وسبتمبرطس مايو ويونيو ويوليو وأغسة فيت الشمسيلتوهجا التي تسببهاجئ المفاف المتأين اغلت البا اضطرا2017 . راتستقبال إشا بنجاح لمراقبة تعمل أن محطة الكتشفنا اFLV كتشاف ، واكتشفناجئة. المفا المتأينة ابات الضطرا17 ا ً حدث عن التوهج الشمسي فئة اً ناتجC ، و8 أحداث من الفئةM و3 أحداث من الفئةX سعة زيادةسببت في تFLV مستلمة ال. INTRODUCTION Space physics is the study of plasmas which are naturally made up in the upper atmosphere of the Earth. Space physics include an extensive variety of topics, such as the study of the sun and the physical relations between the Sun and the solar system called Heliophysics, (from the prefix 'helio,' originally from the Greek Attic hallios, which means Sun) [1] [2]. Consequently, NASA describes it as a systematic new concept for Sun Science-Solar system Link exploring, finding and understanding the Earth's space environment [3]. Space physics is an integral part of space weather science and it has massive consequences for understanding the environment and for communications and satellite operations. As ionosphere reflects the VLF waves, it may be used as a prospective tool for studying the D- region ionosphere which plays an important role in the propagation of radio waves [4][5]. VLF can be used as a D-layer probe because this region is lower than the satellites location and higher than atmospheric balloons. In the Earth-Ionosphere Waveguide (EIWG) which is created between the conducting Earth and the ionosphere, there are radios of extremely low frequency (3 kHz – 30 kHz). They correspond to wavelengths between 100 and 10 km, respectively, transmitting thousands of kilometres. The ionospheric D- region (60 km–90 km altitude) works as the upper border of the Earth Ionosphere Wave Guide EIWG during the day, while at night the region is much weaker and the levels move to higher altitudes [6]. When the x-ray effect stops, the radio blackout also stops and the sudden ionospheric (SID) ends as the D-layer electrons