National Institute of Information and Communications Technology

International Space Environment Service, Regional Warning Center Japan
This site provides the latest information on space environment near Earth

Classification of phenomena

Prediction

Sun
Items Lv. Text Explanation
Solar flare 1 Quiet Solar flare of class C or greater is not expected.
2 Eruptive C class solar flare is expected.
3 Active M class solar flare is expected.
4 Major Flares X class solar flare is expected.
Solar proton 1 Quiet Maximum flux of protons (≧10MeV) is expected to be less than 10 PFU.
2 Warning condition Proton flux (≧10MeV) is expected to increase.
3 Event in progress Maximum flux of protons (≧10MeV) is expected to be 10 PFU or higher.
Magnetosphere
Items Lv. Text Explanation
Geomagnetic disturbance 1 Quiet Maximum K index less than 4 is expected at Kakioka, Japan.
2 Active Maximum K index 4 is expected at Kakioka, Japan.
3 Minor storm Maximum K index 5 is expected at Kakioka, Japan.
4 Major storm Maximum K index 6 is expected at Kakioka, Japan.
5 Severe storm Maximum K index 7 or greater is expected at Kakioka, Japan.
Radiation belt electrons 1 Low 24-h electron fluence (≧ 2 MeV) observed by GOES is less than 3.8 x 107 [/cm2 sr]
2 Moderate 24-h electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 107 and less than 3.8 x 108 [/cm2 sr]
3 High 24-h electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 108 and less than 3.8 x 109 [/cm2 sr]
4 Extreme 24-h electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 109[/cm2 sr]
Ionosphere
Items Lv. Text Explanation
Ionospheric storm *1 1 Quiet Active ionospheric storm is not expected over Japan.
2 Active Ionospheric storm scale of IP2 (more than reference value +3σ and equal to or less than reference value +5σ) or IN2 (equal to or more than reference value -3σ and less than reference value -2σ) with a duration of 2 hours or more is expected over Japan.
3 Severe Ionospheric storm scale of IP3 (more than reference value +5σ) or IN3 (less than reference value -3σ) with a duration of 2 hours or more is expected over Japan.
Dellinger phenomenon 1 Quiet Low probability of Dellinger phenomenon (less than ~30%).
2 Moderate Moderate probability of Dellinger phenomenon (~30 - ~50%).
3 High High probability of Dellinger phenomenon (≥~50%).
Sporadic E-layer 1 Quiet The sporadic-E (Es) layer is not expected to occur over Japan.
Level 2 does not exist.
3 Severe The sporadic-E (Es) layer is expected to occur over Japan.

Current status

　*2 Due to automatic scaled data, it may differ from actual condition.
Sun
Items Lv. Text Explanation
Solar flare 1 Quiet Latest X ray flux is less than 10-6 [W/m2].
2 Eruptive Latest X ray flux is 10-6 [W/m2] or more to less than 10-5 [W/m2].
3 Active Latest X ray flux is 10-5 [W/m2] or more to less than 10-4 [W/m2].
4 Major Flares Latest X ray flux is 10-4 [W/m2] or more.
Solar proton 1 Quiet Latest proton flux (≧10MeV) is less than 10 PFU.
Level 2 does not exist.
3 Event in progress Latest proton flux (≧10MeV) is 10 PFU or more.
Magnetosphere
Items Lv. Text Explanation
Geomagnetic disturbance 1 Quiet Latest K index at Kakioka, Japan is less than 4.
2 Active Latest K index at Kakioka, Japan is 4
3 Minor storm Latest K index at Kakioka, Japan is 5
4 Major storm Latest K index at Kakioka, Japan is 6
5 Severe storm Latest K index at Kakioka, Japan is 7 or greater
Radiation belt electrons 1 Low Laset 24-hour electron fluence (≧ 2 MeV) observed by GOES is less than 3.8 x 107 [/cm2 sr]
2 Moderate Latest 24-hour electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 107 and less than 3.8 x 108 [/cm2 sr]
3 High Latest 24-hour electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 108 and less than 3.8 x 109 [/cm2 sr]
4 Extreme Latest 24-hour electron fluence (≧ 2 MeV) observed by GOES is higher than 3.8 x 109 [/cm2 sr]
Ionosphere
Items Lv. Text Explanation
Ionospheric storm *3, *4 1 Quiet Active ionospheric storm is not occurring over Japan.
2 Active Ionospheric storm scale is IP2 (more than reference value +3σ and equal to or less than reference value +5σ) or IN2 (equal to or more than reference value -3σ and less than reference value -2σ) with a duration of 2 hours or more over Japan.
3 Severe Ionospheric storm scale is IP3 (more than reference value +5σ) or IN3 (less than reference value -3σ) with a duration of 2 hours or more over Japan.
Dellinger phenomenon *3 1 Quiet Dellinger phenomenon is not occurring over Japan.
Level 2 does not exist.
3 Active Dellinger phenomenon is occurring over Japan.
Sporadic E-layer *3 1 Quiet Es layer is not occurring over Japan (Latest Es layer critical frequency (foEs) is below "Active" or “Slightly Active" level) .
2 Slightly Active Latest foEs is between 4.5 MHz and 8 MHz with a duration of 15 minutes or more over Japan.
3 Severe Latest foEs is 8 MHz or more with a duration of 15 minutes or more over Japan.
Sporadic E-layer
(Wakkanai)		 1 Quiet Es layer is not occurring (Latest Es layer critical frequency (foEs) is below "Active" or “Slightly Active" level) .
2 Slightly Active Latest foEs is between 4.5 MHz and 8 MHz with a duration of 15 minutes or more.
3 Severe Latest foEs is 8 MHz or more with a duration of 15 minutes or more.
Sporadic E-layer
(Kokubunji)		 1 Quiet Es layer is not occurring (Latest Es layer critical frequency (foEs) is below "Active" or “Slightly Active" level) .
2 Slightly Active Latest foEs is between 4.5 MHz and 8 MHz with a duration of 15 minutes or more.
3 Severe Latest foEs is 8 MHz or more with a duration of 15 minutes or more.
Sporadic E-layer
(Yamagawa)		 1 Quiet Es layer is not occurring (Latest Es layer critical frequency (foEs) is below "Active" or “Slightly Active" level) .
2 Slightly Active Latest foEs is between 4.5 MHz and 8 MHz with a duration of 15 minutes or more.
3 Severe Latest foEs is 8 MHz or more with a duration of 15 minutes or more.
Sporadic E-layer
(Okinawa)		 1 Quiet Es layer is not occurring (Latest Es layer critical frequency (foEs) is below "Active" or “Slightly Active" level) .
2 Slightly active Latest foEs is between 4.5 MHz and 8 MHz with a duration of 15 minutes or more.
3 Severe Latest foEs is 8 MHz or more with a duration of 15 minutes or more.

Trend levels

　*5 Due to automatic scaled data, it may differ from actual condition.
Sun
Items Lv. Text Explanation
Solar flare 1 Quiet Maximum solar flare was A or B class.
2 Eruptive Maximum solar flare was C class.
3 Active Maximum solar flare was M class.
4 Major Flares Maximum solar flare was X class.
Solar proton 1 Quiet Maximum proton flux (≧10MeV) was less than 10 PFU.
Level 2 does not exist.
3 Event occurred Maximum proton flux (≧10MeV) was 10 PFU or more.
Magnetosphere
Items Lv. Text Explanation
Geomagnetic disturbance 1 Quiet Maximum K index at Kakioka, Japan was less than 4.
2 Active Maximum K index at Kakioka, Japan was 4.
3 Minor storm Maximum K index at Kakioka, Japan was 5.
4 Major storm Maximum K index at Kakioka, Japan was 6.
5 Severe storm Maximum K index at Kakioka, Japan was 7 or greater.
Radiation belt electrons 1 Low 24-hour electron fluence (≧ 2 MeV) observed by GOES was less than 3.8 x 107 [/cm2 sr]
2 Moderate 24-hour electron fluence (≧ 2 MeV) observed by GOES was higher than 3.8 x 107 and less than 3.8 x 108 [/cm2 sr]
3 High 24-hour electron fluence (≧ 2 MeV) observed by GOES was higher than 3.8 x 108 and less than 3.8 x 109 [/cm2 sr]
4 Extreme 24-hour electron fluence (≧ 2 MeV) observed by GOES was higher than 3.8 x 109 [/cm2 sr]
Ionosphere
Items Lv. Text Explanation
Ionospheric storm *6, *7 1 Quiet Active ionospheric storm did not occur over Japan.
2 Active Ionospheric storm scale was IP2 (more than reference value +3σ and equal to or less than reference value +5σ) or IN2 (equal to or more than reference value -3σ and less than reference value -2σ) with a duration of 2 hours or more over Japan.
3 Severe Ionospheric storm scale was IP3 (more than reference value +5σ) or IN3 (less than reference value -3σ) with a duration of 2 hours or more over Japan.
Dellinger phenomenon *6 1 Quiet Dellinger phenomenon did not occur over Japan.
Level 2 does not exist.
3 Active Dellinger phenomenon occurred over Japan (Maximum fmin of more than "reference value +3.5 MHz“ or black out associated with solar flare(s)).
Sporadic E-layer *6 1 Quiet Es did not occur over Japan (Latest Es layer critical frequency (foEs) was below "Active" or “Slightly Active" level).
2 Slightly active foEs was between 4.5 MHz and 8 MHz with a duration of 15 minutes or more over Japan.
3 Severe foEs was 8 MHz or more with a duration of 15 minutes or more over Japan.