01. 2011年6月16日 19:05:05: Pj82T22SRI
>As the current sunspot cycle, Cycle 24, begins to ramp up toward maximum, independent studies of the solar interior, visible surface, and the corona indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.ほお。NICTは太陽活動の活発化を予想していたから、正反対だな
http://journal.mycom.co.jp/news/2011/02/17/001/index.html 2011/02/17
太陽活動が再び活発に 〜 第24太陽活動サイクル初の大型フレアを確認 〜
2011年02月16日
情報通信研究機構（以下「NICT」、理事長：宮原秀夫）は、2011年2月15日(火)10時44分（日本時間）に大型の太陽フレア現象を 確認しました。このような大型の太陽フレア発生は約4年ぶりであり、数年間にわたって静穏であった太陽活動が活発化に転じたことを示唆しています。太陽活 動が活発化することで、今後は数年間にわたり、通信衛星や放送衛星などの人工衛星の障害、GPSを用いた高精度測位の誤差、短波通信障害などの発生確率が 高くなっていくと予想しています。今回の太陽フレアの影響は2月17日(木)〜18日(金)未明頃に到来すると予想されます。
NICTは、2011年2月15日(火)10時44分（日本時間）に、大型の太陽フレア現象を確認しました。今回の太陽フレアに伴うX線強度は通常時の100倍以上（最大時）であり、この規模の太陽フレア発生は、2006年12月以来となります。 一般に、大規模な太陽フレアが発生した場合には、それに伴う様々な環境変動が地球近傍の宇宙空間で生じます。これらの宇宙環境変動には、フレア発生 直後（数分程度）に確認される変動と、数日かけて地球に到来してから確認される変動があります。前者については、NICTの観測により、太陽フレアによる太陽電波バースト現象と電離圏および地磁気変動を確認しました。後者については、2月17日(木)〜18日（金）未明頃に地球に到来すると予想しています。
1）本日までに確認された現象
・太陽フレアに伴う太陽電波バースト現象
NICTの太陽監視望遠鏡により、大型の太陽フレア現象（図１参照）が確認されました。また、NICTの電波望遠鏡により、太陽フレアに伴うコロナ質量放出現象、及びその前面の衝撃波から発生したと考えられる電波を観測しました。
・太陽フレアに伴う電離圏現象（デリンジャー現象）
太陽フレア発生に伴い、稚内、東京、沖縄を含む日本全域上空の電離圏において、NICTの電離圏観測装置がデリンジャー現象を観測しました。
2）本太陽フレアに伴い、今後発生が予想される現象
・磁気嵐現象
地球周辺の宇宙環境が大規模に変動し、これに伴う地磁気の乱れや地球周辺の高エネルギー粒子の到来により、通信衛星や放送衛星などの人工衛星に障害が発生する可能性があります。また、オーロラ活動が活発になることがあります。
・電離圏嵐現象
電離圏の状態が変動し、短波通信等の無線通信への障害や、GPSを用いた高精度測位の精度が一時的に劣化する現象が生じる可能性があります。
NICTでは、太陽活動や宇宙環境変動の情報提供を長年にわたり行ってきました。2008年1月頃から始まった第24太陽活動サイクルは、これまでの太陽サイクルと比べ静穏でした（図3参照）が、今回の現象により、今後の太陽活動は活発化に向かうと考えています。活発化に伴い、今回の現象のような宇宙環境が乱れた状態が発生しやすくなると考えています。今後の宇宙環境の状態については、NICTの宇宙天気予報ポータルサイトで随時提供していきます。
＜ 取材依頼及び広報 問い合わせ先 ＞総合企画部広報室報道担当 廣田 幸子Tel：042-327-6923 Fax：042-327-7587
＜本件に関する 問い合わせ先＞電磁波計測研究センター宇宙環境計測グループ研究マネージャー 長妻 努Tel：042-327-6095Fax：042-327-6163 太陽フレア現象
太陽の黒点群の領域で生じる爆発現象。太陽フレアに伴い、強い紫外線やX線、電波等が放射される他、CME現象が生じることもある。
太陽電波バースト現象
太陽電波強度が急激に増大する現象。太陽フレアやCME現象、衝撃波等から放射されることがある。
コロナ質量放出現象（Colonal Mass Ejection(CME)現象）
太陽の上層大気であるコロナのガスが惑星間空間に放出される現象。地球に到来すると大規模な宇宙環境変動を引き起こすことがある。
デリンジャー現象
太陽フレア現象によって放射される強い紫外線やX線の影響で電離圏の下部領域が異常電離し、短波を吸収することで生じる現象。これにより、漁業無線などの短波通信に障害が発生することがある。
第24太陽活動サイクル
太陽活動はほぼ11年の周期で変動しており、その周期的な変動をサイクルとして1755年から数えている。第24太陽活動サイクルは2008年1月から開始したと考えられている（図3）。
http://encyclopedia.thefreedictionary.com/Maunder+Minimum
Maunder Minimum
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The Maunder minimum in a 400 year history of sunspot numbers
The Maunder Minimum (also known as the prolonged sunspot minimum) is the name used for the period roughly spanning 1645 to 1715 when sunspots became exceedingly rare, as noted by solar observers of the time. The concept became notable after John A. Eddy published a landmark 1976 paper in Science titled "The Maunder Minimum".[1] Astronomers before Eddy had also named the period after the solar astronomer Edward W. Maunder (1851-1928) who studied how sunspot latitudes changed with time.[2] The periods he examined included the second half of the 17th century. Edward Maunder published two papers in 1890 and 1894, and he cited earlier papers written by Gustav Spörer. Like the Dalton Minimum and Spörer Minimum, the Maunder Minimum coincided with a period of lower-than-average global temperatures. During one 30-year period within the Maunder Minimum, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000-50,000 spots in modern times.[citation needed]
Sunspot observations The Maunder Minimum occurred between 1645 and 1715 when very few sunspots were observed. This was not due to a lack of observations; during the 17th century, Giovanni Domenico Cassini carried out a systematic program of solar observations at the Observatoire de Paris, thanks to the astronomers Jean Picard and Philippe de La Hire. Johannes Hevelius also performed observations on his own. The total numbers of sunspots (but not Wolf numbers) in different years were as follows:
Year Sunspots
1610 9
1620 6
1630 9
1640 0
1650 3
1660 Some sunspots reported by Jan Heweliusz in "Machina Coelestis"
1670 0
1680 1 huge sunspot observed by Giovanni Domenico Cassini During the Maunder Minimum enough sunspots were sighted so that 11-year cycles could be extrapolated from the count. The maxima occurred in 1676, 1684, 1695, 1705 and 1716. The sunspot activity was then concentrated in the southern hemisphere of the Sun, except for the last cycle when the sunspots appeared in the northern hemisphere, too. According to Spörer's law, at the start of a cycle, spots appear at ever lower latitudes until they average at about lat. 15° at solar maximum. The average then continues to drift lower to about 7° and after that, while spots of the old cycle fade, new cycle spots start appearing again at high latitudes. The visibility of these spots is also affected by the velocity of the sun's rotation at various latitudes:
Solar latitude Rotation period
(days)
0° 24.7
35° 26.7
40° 28.0
75° 33.0 Visibility is somewhat affected by observations being done from the ecliptic. The ecliptic is inclined 7° from the plane of the Sun's equator (latitude 0°).
Little Ice Age The Maunder Minimum coincided with the middle - and coldest part - of the Little Ice Age, during which Europe and North America were subjected to bitterly cold winters. Whether there is a causal connection between low sunspot activity and cold winters has not been proven; however, lower earth temperatures have been observed during low sunspot activity.[3] The winter of 1708-09 was extremely cold.[4]
Other observations
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Solar activity events recorded in radiocarbon.
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Graph showing proxies of solar activity, including changes in sunspot number and cosmogenic isotope production. Some scientists hypothesize that the dense wood used in Stradivarius instruments was caused by slow tree growth during the cooler period. Instrument maker Antonio Stradivari was born a year before the start of the Maunder Minimum.[5] Past solar activity may be recorded by various proxies including carbon-14 and beryllium-10 [1]. These indicate lower solar activity during the Maunder Minimum. The scale of changes resulting in the production of carbon-14 in one cycle is small (about 1 percent of medium abundance) and can be taken into account when radiocarbon dating is used to determine the age of archaeological artifacts. Other historical sunspot minima have been detected either directly or by the analysis of carbon-14 in tree rings; these include the Spörer Minimum (1450-1540), and less markedly the Dalton Minimum (1790-1820). In total there seem to have been 18 periods of sunspot minima in the last 8,000 years, and studies indicate that the sun currently spends up to a quarter of its time in these minima. One recently published paper, based on an analysis of a Flamsteed drawing, suggests that the Sun's rotation slowed in the deep Maunder minimum (1684).[6] During the Maunder Minimum auroras had been observed normally. Detailed analysis has been published by Wilfried Schröder[7] and J. P. Legrand et al.[8] Curiously, the duration of the Maunder Minimum (1645-1715) coincides very closely with the reign of King Louis XIV of France (1643-1715), known as the Sun King. The fundamental papers on the Maunder minimum (Eddy, Legrand, Gleissberg, Schröder, Landsberg et al.) have been published in Case studies on the Spörer, Maunder and Dalton Minima.[9]
See also Global Warming
Spörer Minimum
Solar minimum
John A. Eddy, the astronomer who popularised the Maunder Minimum References ^ Eddy J.A. (June 1976). "The Maunder Minimum". Science 192 (4245): 1189?1202. doi:10.1126/science.192.4245.1189. PMID 17771739. PDF Copy
^ Who named the Maunder Minimum?
^ Clark, Stuart (June 9, 2010). "What's wrong with the sun?". New Scientist (2764): 30?5.
^ Niles' Weekly Register, Volume 15, Supplement, History of the Weather
^ Whitehouse, David (December 17, 2003). "Stradivarius 'sound' due to Sun". BBC News. Retrieved 2009-05-12.
^ Vaquero J.M., Sánchez-bajo F., Gallego M.C. (2002). "A Measure of the Solar Rotation During the Maunder Minimum". Solar Physics 207 (2): 219. doi:10.1023/A:1016262813525.
^ Schröder, Wilfried (1992). "On the existence of the 11-year cycle in solar and auroral activity before and during the so-called Maunder Minimum". Journal of Geomagnetism and Geoelectricity 44 (2): 119?128. ISSN 00221392.
^ Legrand, J. P.; Le Goff, M.; Mazaudier, C.; Schröder, W. (1992). "Solar and auroral activities during the seventeenth century". Acta Geophysics and Geodetica Hungarica 27 (2?4): 251?282.
^ Schröder, Wilfried (2005). Case studies on the Spörer, Maunder, and Dalton minima. Beiträge zur Geschichte der Geophysik und Kosmischen Physik. 6. Potsdam: AKGGP, Science Edition. Further reading Luterbach, J.; et al. (2001). "The Late Maunder Minimum (1675-1715) - A Key Period for Studying Decadal Scale Climatic Change in Europe". Climatic Change 49 (4): 441-462. doi:10.1023/A:1010667524422.
Willie Wei-Hock Soon; Yaskell, Steven H. (2003). The Maunder minimum and the variable sun-earth connection. River Edge, NJ: World Scientific. pp. 278. ISBN 9812382755.
What's wrong with the sun? (Nothing)
http://astronomy.nmsu.edu/SPD2011/
http://www.spaceref.com/news/viewpr.html?pid=33826%29
Major Drop in Solar Activity Predicted
Source: National Solar Observatory
Posted Tuesday, June 14, 2011
The Sun viewed in visible light, at minimum phase (2006) and maximum phase (2001)A missing jet stream, fading spots, and slower activity near the poles say that our Sun is heading for a rest period even as it is acting up for the first time in years, according to scientists at the National Solar Observatory (NSO) and the Air Force Research Laboratory (AFRL).As the current sunspot cycle, Cycle 24, begins to ramp up toward maximum, independent studies of the solar interior, visible surface, and the corona indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.The results were announced at the annual meeting of the SolarPhysics Division of the American Astronomical Society, which is being held this week at New Mexico State University in Las Cruces: http://astronomy.nmsu.edu/SPD2011/"This is highly unusual and unexpected," Dr. Frank Hill, associate director of the NSO's Solar Synoptic Network, said of the results. "But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation."Spot numbers and other solar activity rise and fall about every 11 years, which is half of the Sun's 22-year magnetic interval since the Sun's magnetic poles reverse with each cycle. An immediate question is whether this slowdown presages a second MaunderMinimum, a 70-year period with virtually no sunspots during 1645-1715.Mobile "jet streams" in the Sun migrate from the poles toward the equator as the solar cycle progresses. At left (solarminimum) the red jet streams are located near the poles. At right (solar maximum) they have migrated close to the equator. The jet streams are associated with the locations where sunspots emerge during the solar cycle, and are thought to play an important role in generating the Sun's magnetic field.Hill is the lead author on one of three papers on these results being presented this week. Using data from the Global Oscillation Network Group (GONG) of six observing stations around the world, the team translates surface pulsations caused by sound reverberating through the Sun into models of the internal structure. One of their discoveries is an east-west zonal wind flow inside the Sun, called the torsional oscillation, which starts at mid-latitudes and migrates towards the equator. The latitude of this wind stream matches the new spot formation in each cycle, and successfully predicted the late onset of the current Cycle 24."We expected to see the start of the zonal flow for Cycle 25 by now," Hill explained, "but we see no sign of it. This indicates that the start of Cycle 25 may be delayed to 2021 or 2022, or may not happen at all."In the second paper, Matt Penn and William Livingston see a long-term weakening trend in the strength of sunspots, and predict that by Cycle 25 magnetic fields erupting on the Sun will be so weak that few if any sunspots will be formed. Spots are formed when intense magnetic flux tubes erupt from the interior and keep cooled gas from circulating back to the interior. For typical sunspots this magnetism has a strength of 2,500 to 3,500 gauss (Earth's magnetic field is less than 1 gauss at the surface); the field must reach at least 1,500 gauss to form a dark spot.Using more than 13 years of sunspot data collected at the McMath-Pierce Telescope at KittPeak in Arizona, Penn and Livingston observed that the average field strength declined about 50 gauss per year during Cycle 23 and now in Cycle 24. They also observed that spot temperatures have risen exactly as expected for such changes in the magnetic field. If the trend continues, the field strength will drop below the 1,500 gauss threshold and spots will largely disappear as the magnetic field is no longer strong enough to overcome convective forces on the solar surface.Latitude-time plots of jet streams under the Sun's surface show the surprising shutdown of the solar cycle mechanism. New jet streams typically form at about 50 degrees latitude (as in 1999 on this plot) and are associated with the following solar cycle 11 years later. New jet streams associated with a future 2018-2020 solar maximum were expected to form by 2008 but are not present even now, indicating a delayed or missing Cycle 25.Moving outward, Richard Altrock, manager of the Air Force's coronal research program at NSO's Sunspot, NM, facilities has observed a slowing of the "rush to the poles," the rapid poleward march of magnetic activity observed in the Sun's faint corona. Altrock used four decades of observations with NSO's 40-cm (16-inch) coronagraphic telescope at Sunspot."A key thing to understand is that those wonderful, delicate coronal features are actually powerful, robust magnetic structures rooted in the interior of the Sun," Altrock explained. "Changes we see in the corona reflect changes deep inside the Sun."Altrock used a photometer to map iron heated to 2 million degrees C (3.6 million F). Stripped of half of its electrons, it is easily concentrated by magnetism rising from the Sun. In a well-known pattern, new solar activity emerges first at about 70 degrees latitude at the start of a cycle, then towards the equator as the cycle ages. At the same time, the new magneticfields push remnants of the older cycle as far as 85 degrees poleward."In cycles 21 through 23, solar maximum occurred when this rush appeared at an average latitude of 76 degrees," Altrock said. "Cycle 24 started out late and slow and may not be strong enough to create a rush to the poles, indicating we'll see a very weak solar maximum in 2013, if at all. If the rush to the poles fails to complete, this creates a tremendous dilemma for the theorists, as it would mean that Cycle 23's magnetic field will not completely disappear from the polar regions (the rush to the poles accomplishes this feat). No one knows what the Sun will do in that case."All three of these lines of research to point to the familiar sunspotcycle shutting down for a while."If we are right," Hill concluded, "this could be the last solar maximum we'll see for a few decades. That would affect everything from space exploration to Earth's climate."- More diagrams available
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