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Local K-Index


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Local K Index



The S4 Index is a standard index used to measure ionospheric disturbances. It is defined as the ratio of the standard deviation of signal intensity to the average signal intensity.




Daily Brief

Issued By Pussainsa 2022-01-26

Solar Activity / X Ray Flares

Solar activity was eruptive for the last 24 hours.

There were 6 C-class flares that occurred in the last 24 hours. The maximum flare class was C9.9 from NOAA 2936 peaked at 22:44 UT in the last 24 hours. The type-III solar radio burst occurred 1 time. CME occurred 1 time in the last 24 hours. The east-directed CME has the highest median velocity of 454.0 km/s with an angular width of 10 degrees. The latest SDO/HMI Intensitygram data shows 4 active regions (NOAA 2934, 2935, 2936, and 2937), and the latest BBSO H-Alpha data shows 1 H-alpha plages (NOAA 2932). STEREO/EUVI observation shows 1 new active region is going to appear from the east limb of the Solar disk in the next 24 hours.

Based on today’s condition solar activity for the next 24 hours is predicted to be eruptive.


Solar Wind / Geomagnetic Activity

The geomagnetic activity was on active level for the last 24 hours.

The solar wind speed increase from 334 km/s and 508 km/s, north-south component of interplanetary magnetic field fluctuate between -9.2 nT and 10.5 nT There was geoeffective coronal hole at central equator, while the others at north-east and south pole were not geoeffective. There was substrom occurrence in the last 24 hours, started at 08:07 UT lasted for 5 hours 37 minutes with maximum intensity less than 1000 nT.

Quiet level geomagnetic activity is expected for the next 24 hours.

Ionosphere / Scintillation

The ionosphere was quiet for the last 24 hours.

There was no depression of foF2 lower than 30% of its median values. There was an increment of fmin more than 30% of its median values for 405 minutes. The Spread-F occur in the last 24 hours for 225 minutes. The Sporadic-E occurred in the night and daytime for 630 minutes. The W-index mean value was -1. The S4 index value (condition of ionospheric scintillation) was less than 0.5 over Bandung.

The ionosphere for the next 24 hours is predicted to be quiet.

Solar Energetic Particles (Protons)

The flux of high-energy protons was at a quiet level due to low solar activity.
Based on today's condition, the flux of high-energy proton for the next 24 hours is predicted to be quiet.