地磁気世界資料解析センター News No.82 2003年11月30日 １．新着地磁気データ 前回ニュース（2003年9月30日発行, No.81）以降入手、または、当センターで入力したデータの うち、主なものは以下のとおりです。オンライン利用データの詳細は (http://swdcwww.kugi.kyoto-u.ac.jp/catmap/index-j.html) を、観測所名の省略記号等については、観測所カ タログ（http://swdcwww.kugi.kyoto-u.ac.jp/catmap/obs-j.html) をご参照ください。 また、先週の新着オンライン利用可データは、 (http://swdcwww.kugi.kyoto-u.ac.jp/wdc/onnew/onnew-j.html)で御覧になれます。 Newly Arrived Data （１）Annual Reports and etc. SOD, OUJ, HAN, NUR(Sep.- Oct., 2003), AQU(2002), LRV(2002), NGK (Sep., 2003) （２）Digital Data オンライン利用データカタログ (http://swdcwww.kugi.kyoto-u.ac.jp/catmap/index-j.html) 及び新着オンライン利用可データ (http://swdcwww.kugi.kyoto-u.ac.jp/wdc/onnew/onnew-j.html) をご参照願います。 （３）Kp index: (http://swdcwww.kugi.kyoto-u.ac.jp/kp/index-j.html) Sep. - Oct., 2003 ２．１時間値Dst指数とASY/SYM指数 Quick Look Dst指数（http://swdcwww.kugi.kyoto-u.ac.jp/dstdir/dst1/quick.html) および Quick Look AE 指数 (http://swdcwww.kugi.kyoto-u.ac.jp/aedir/ae/quick.html) は1日以内の遅れで当センターのホームペー ジから利用できます。 ３．２１世紀ＣＯＥプログラムへの参加とＣＯＥ外国人研究員の着任 今年度採択の京都大学21世紀COEプロジェクト『活地球圏の変動解明 -アジア・オセアニアから 世界への発信- 』（代表：余田成男 理学研究科教授）への取り組みの一部として、当センターが中心と なり、このプロジェクトのポータルサイトの構築を推進することになりました。現在はまだ仮のホーム ページ http://swdcft49.kugi.kyoto-u.ac.jp/kagi/index_j.htm を立ち上げたばかりですが、その英語ページの担当およ び電磁気的手法を用いた活地球圏科学研究推進のため、オーストラリア出身のヘザー・マクレイディ博士 が１１月から着任しました。研究室は地磁気センター内にあり、このＣＯＥプロジェクトに密接に関連 する地磁気センターの活動にも一部参加しています。 ４．ＣＯＥ外国人研究員自己紹介−Dr. Heather McCreadie, COE Research Fellow I started my career at Latrobe University, Melbourne, Australia where I obtained an undergraduate degree in Geology and Physics. After a brief stint in the gold mining industry, I returned to Latrobe University to complete an Honours degree in physics. It was in this year I was introduced to geomagnetism. Under the aegis of Dr. Eric Butcher I researched the topic of abnormal quiet days in Sq. This whetted my appetite for the subject and I continued with my studies, this time working on the annual and semiannual variations in night-time, ground-based geomagnetic observatory data. This work allowed me to be admitted to the degree of Doctor of Philosophy (physics). Thereafter, I worked with Dr. Elizabeth Essex in the field of GPS occultations using the FedSat satellite. This involved modeling the orbit of the satellite with respect to areas of dense TEC. My next move was to AGSO, now known and Geoscience Australia in Canberra. There I worked under the aegis of Dr. Charles Barton. Here I came into contact with magnetic instruments for the first time. I was in charge of Gnangara and Learmonth magnetic stations in Western Australia . I contributed to the Kp index valuations, instrument observations and recovery, and the repeat station survey. I was also a delegate for the Australian Disaster Information Network. This allowed me to understand how scientists, engineers and lay persons needed to interact with each other in order to evaluate recovery and prevention techniques for any type of large scale disaster. I felt I needed to see the world so I then moved on to work as a research scientist at GeoForschungsZentrum in Potsdam, Germany. The CHAMP satellite had just been launched and the data beckoned to be studied. Under the aegis of Prof. Volker Haak I worked on data from the Overhauser magnetometer and the vector magnetometer on board CHAMP. My own project was in the area of the equatorial electrojet and the Sq system and I worked on induction in mantle using thesatellite data with a group headed by Prof. Multi Zdenek Martinec from the University of Prague. Currently, I am employed by the COE project “Elucidation of the Active Geosphere” at the University of Kyoto. If you have any questions or just feel like chat, feel free to come and visit me any time. My computer alias is bilby. Many people ask me, “What is a bilby?” They are a rabbit size marsupial with large ears and their fur is soft grey with a bluish tinge. A long pointed snout and a large black and white tail with a white brush tip makes this a striking looking animal. Strong claws enables this marsupial to burrow quickly through sandy soil and the bilby’s pouch faces backwards. Size wise they range from 30 to 60 cm in length with roughly a 20cm tail. They live in Australia and are an endangered species, just like me. < A Macrotis Lagotis < Hmmm?> otherwise known as a Bilby> ５．Geoeffectiveness of Intense Solar events (Sobhana Alex) The tenuous atmosphere of the Sun undergoes sudden and dramatic changes. Solar flare is one of the important phenomena, which occurs due to the sudden release of the magnetic energy built up in the solar atmosphere in a spontaneous manner. This process results in the emission of intense energies in the entire wavelengths spanning from radio waves to X-rays and gamma rays. X-ray radiations of intense energies produce their effect on the ground magnetic records as a sporadic increase in the earth’s magnetic field within few minutes of the flare occurrence on the Sun. Solar activity and the physics of Sun-earth interaction process has been a topic of immense importance in the last three decades, due to its impact on advancement in technological applications. Solar cycle 23 had its maximum peak during the years 2000-2001. Close correspondence between the occurrence frequency of solar flares and solar activity is well known, as the sunspots are visible in regions of high magnetic field strengths. However, the recent eruptions occurred from the tenuous atmosphere of the Sun seemed to produce flares of strikingly large magnitude and unleashing billions of tons of charged particles of enormous speed, towards the last week of October 2003. As was observed and reported by solar observers, development of several spots started becoming visible from 24 October 2003. From October 24, a Jupiter sized giant sunspot 486 became an active one to produce a major flare of X17 magnitude on October 28. This blast on 28 October, unleashed billions of tons of electrically charged particles barreling into space toward Earth, as a cloud of hot electrified gas, streaming with speed greater than 2000 km/sec (5 million mph). These solar ejecta produced a geomagnetic storm on October 29, within 19 hours of the energy release. As suggested by Dr. Kappenman , the coupling process between the Sun-earth was quite weak , allowing the interaction of the Interplanetary Magnetic Field( IMF) with the earth’s magnetosphere for almost one third of its passage time through the earth. Subsequent to this dynamic exprosive event, more than a dozen X - class flares were reported. Coronal masss ejections of predominant strength in the months of October and November 2003 and subsequent storm occurrences have posed problem among the space scientists concerning the understanding of the energy transfer process from Sun to Earth through the interaction of the Interplanetary Magnetic Field and the magnetosphere of the earth. Some of the basic physics on the geomagnetic storm phenomenon could be explained from the recent investigation reported by the scientists G.S.Lakhina and S.Alex of Indian Institute of Geomagnetism, India in collaboration with the scientists Bruce Tsurutani, Jet Propulsion Laboratory, USA and Walter Gonzalez , INPE, Brazil. This work has brought out the characteristics of the geomagnetic storm that happened 144 years ago in September 1-2, 1859 , as deciphered from the manual observations of the geomagnetic field from the Colaba/Mumbai (Geomag.Lat.9.87°N; Long. 142.7°E) magnetic observatory. The magnetic data for this event has been recently calibrated and deduced from the measurements of the Horizontal magnetic field from the Grubb magnetometer for hourly intervals prior to the storm beginning and 15 minutes intervals during the disturbed period of the event. The occurrence feature and the magnitude of the storm of 1-2 September 1859, as evidenced from the low latitude magnetic measurements at Colaba, has close relevance to the observations and the suggestions based on the report of the first ever recorded, solar flare observations, by Carrington in 1859 and Hodgson in 1859, in the Monthly Notices of the Royal Astronomical Society of astronomical literature. It was shown that the time delay of the storm beginning associated with the Carrington solar flare and as stated in Carrington’s report of 17 hour 40 minutes has matched well with the storm record at Colaba. The magnetic field decrease in the Horizontal component at Colaba was ~ -1600 nT. Thus comparing the impact time and the magnitude of the super storms, which occurred almost 144 years ago and the recent geomagnetic storm event of October 29, 2003, the variable nature of the storm intensity has created certain unanswered problems. The paradigm on whether the solar activity is the key parameter or the magnetic field characteristics within the energy release from the Sun judge the extent of its geoeffectiveness? Thus a combined investigation of statistical nature based on the ground based magnetic data for extended time periods and the available interplanetary and solar observations is the need of the time to improvise the knowledge of the space weather aspects of highly energetic solar events.
Quick look digital magnetie record of the three components H, D and Z, recorded and transmitted from Alibag Manetic Observatory (Geomag Lat. 10.03 °N, Long. 146°E) on the storm day , October 29, 2003. Multiple step storm is evident during the main phase. <紹介> Prof. Sobhana Alex は、インド地磁気研究所の観測およびデータ解析部門の責任者で、１１月２６日から １２月９日まで、ＩＡＧＡのプロジェクトの一つである地磁気観測古記録の保存（Old Magnetogram Rescue）の関係で、そのプロジェクト推進の中心となっている当地磁気センターを訪問し、マグネトグラ ムのディジタル画像化などについて、打ち合わせを行っています。