Press Release
February 17, 2011
The Sun Comes Back Active Again
- Occurrence of the First Major Solar Flare during Solar Cycle 24th -
- Occurrence of the First Major Solar Flare during Solar Cycle 24th -
National Institute of Information and Communications Technology (hereinafter called NICT, President: Hideo Miyahara) has confirmed an occurrence of major solar flare (X-class flare) at 10:44 JST Tuesday, Feb. 15, 2011. This is the first X-class solar flare in the solar cycle 24. The last commencement of the X-class flare was in December 2006 during the previous solar cycle, suggesting that the activity of the sun has come back and attentions should be paid to space weather information: malfunctions of artificial satellites, increasing errors of high-precision positioning by GPS, and problems of short-wave communications may take place. The present solar flare is expected to effect the Earth’s space environment around Thursday, Feb. 17 or early hours of Friday, Feb. 18.
NICT has confirmed an occurrence of major solar flare at 10:44 JST Feb.15 ,2011, using our own space weather observation facilities. The maximum intensity of X-ray emitted from the current major flare is more than 100 times larger than the usual ones, and a previous major flare was occurred at December 2006, more than 4 years ago.
In general, many kinds of space weather disturbances will happen corresponding to the occurrence of major solar flare. There are two types of space weather disturbances, disturbances right after and several days after. We have confirmed the occurrence of former types of disturbances such as solar radio bursts, ionospheric phenomena, and geomagnetic disturbances. We anticipate the latter type of disturbances around from Thursday, Feb. 17 to the before daytime of Friday, Feb. 18.
In general, many kinds of space weather disturbances will happen corresponding to the occurrence of major solar flare. There are two types of space weather disturbances, disturbances right after and several days after. We have confirmed the occurrence of former types of disturbances such as solar radio bursts, ionospheric phenomena, and geomagnetic disturbances. We anticipate the latter type of disturbances around from Thursday, Feb. 17 to the before daytime of Friday, Feb. 18.
1) Space weather disturbances which were confirmed by our observation facilities
・
Solar radio bursts correspond to this major solar flare
We have confirmed that the occurrence of major solar flare using NICT's optical telescope (See Figure 1). Further, NICT's radio spectrograph observed two types of event, which corresponds to the coronal mass ejections and shock waves caused by the solar flare (See Figure 2).
We have confirmed that the occurrence of major solar flare using NICT's optical telescope (See Figure 1). Further, NICT's radio spectrograph observed two types of event, which corresponds to the coronal mass ejections and shock waves caused by the solar flare (See Figure 2).
・
Ionospheric phenomena (short-wave fade-out) corresponds to this major flare
NICT's Ionospheric observation network has detected short-wave fade-out phenomena corresponding to the major solar flare.
NICT's Ionospheric observation network has detected short-wave fade-out phenomena corresponding to the major solar flare.
2) Space weather disturbances which anticipated occurring due to major solar flare effect
・
Geomagnetic storm
Due to geomagnetic and high-energy particle disturbances around the Earth's space environment as geomagnetic storm, increasing risk of satellite malfunctions and frequent auroral activities are anticipated.
Due to geomagnetic and high-energy particle disturbances around the Earth's space environment as geomagnetic storm, increasing risk of satellite malfunctions and frequent auroral activities are anticipated.
・
Ionospheric storm
Due to significant changes of ionospheric conditions, problems of short-wave communications and increasing errors of high-precision positioning by GPS are anticipated.
Due to significant changes of ionospheric conditions, problems of short-wave communications and increasing errors of high-precision positioning by GPS are anticipated.
NICT has been provided solar and space environment information as space weather for a long time. Solar cycle 24th is anticipated to be active from now on, although the calm conditions have been continued for several years (Figure 3).
We anticipated that frequent occurrence of space weather disturbances. We will provide current and future conditions of space environment information from the following web pages （http://www2.nict.go.jp/y/y223/sw_portal/sw_portal-e.html）.
We anticipated that frequent occurrence of space weather disturbances. We will provide current and future conditions of space environment information from the following web pages （http://www2.nict.go.jp/y/y223/sw_portal/sw_portal-e.html）.
< Media Contact >
Public Relations Office
Strategic Planning Dept.
Sachiko HIROTA
Tel：+81-42-327-6923
Public Relations Office
Strategic Planning Dept.
Sachiko HIROTA
Tel：+81-42-327-6923
< Technical Contact >
Space Environment Group,
Applied Electromagnetic Research Center
Tsutomu NAGATSUMA
Tel：+81-42-327-6095
Space Environment Group,
Applied Electromagnetic Research Center
Tsutomu NAGATSUMA
Tel：+81-42-327-6095
Supplementary Information
|
(Related links）
NICT's space weather portal http://www2.nict.go.jp/y/y223/sw_portal/sw_portal-e.html Information of radio propagation condition http://wdc.nict.go.jp/IONO/index_E.html Figure 1. A full disk H-alpha solar image taken by optical telescopes at Hiraiso Solar Observatory (2011/02/15 14:45 JST) [The sunspot group which produces major solar flare is shown in the dashed red circle] |
Figure 2: Solar Radio burst events observed by NICT's radio spectrograph (HiRAS) at Hiraiso Solar Observatory (from 10:50 to 11:10 UT). Warmer color shows higher intensity of radio signals. Type IV radio burst corresponds to coronal mass ejections, type II radio burst corresponds to shock waves.
Figure 3. Plot of relative sunspot number from year of 2000 to 2019. Red line shows
predicted values.
（From NOAA/SWPC）
（From NOAA/SWPC）