Detailed Information

Solar Activity

Solar activity for April 10th, 2026 04:00 UT - April 11th, 2026 03:59 UT was quiet,
Solar activity for April 11th, 2026 04:00 UT - April 12th, 2026 03:59 UT was eruptive,
Solar activity for April 12th, 2026 04:00 UT - April 13th, 2026 03:59 UT was eruptive,

Three C-class solar flares were observed in the last 24 hours. The most significant event was a C2.4 flare from NOAA 14417, peaking at 7:38UT. Associated with this activity, no solar radio bursts were observed. Furthermore, no coronal mass ejections were observed. On the visible disk, three active regions were identified by SDO/HMI, namely NOAA 14415, NOAA 14416, and NOAA 14417. Meanwhile, BBSO H-alpha observations showed three plages, NOAA 14411, NOAA 14412, and NOAA 14414. One farside region is expected to return to the visible disk between April 13 and April 15. 
Solar activity over the next 24 hours is predicted to be eruptive.

Geomagnetic Activity

Geomagnetic activity was at a quiet level from 10 April 2026 07UT to 11 April 2026 07UT.
Geomagnetic activity was at a quiet level from 11 April 2026 07UT to 12 April 2026 07UT.
Geomagnetic activity was at a quiet level over the last 24 hours.

The solar wind speed decreased from 645 km/s to 435 km/s, and the north-south component of the interplanetary magnetic field fluctuated between -6.2 nT and 6.6 nT. There were geoeffective coronal holes at the western equator, while the others at the eastern equator, southeast, south pole, and southwest were not geoeffective.

Quiet geomagnetic conditions are expected for the next 24 hours.

Ionospheric Activity

The ionosphere was in quiet conditions on April 10th, 04:00 UT - April 11th, 03:59 UT.
The ionosphere was in minor conditions on April 11th, 04:00 UT – April 12th, 03:59 UT.
The ionosphere was in quiet conditions on April 12th, 04:00 UT – April 13th, 03:59 UT.

There was a depression of foF2 below 30% of its median value for 0, 15, and 75 minutes on 10 - 13 April 2026. There was an increase in fmin of more than 30% above its median values at 0, 30, and 15 minutes on 10 - 13 April 2026. No Spread-F occurred in the last 72 hours. The Sporadic-E did occur in the night and daytime with foEs values exceeding the foF2 values for 1380, 1455, and 1365 minutes on 10 - 13 April 2026. The S4 index values (condition of ionospheric scintillation) were S4 < 0.5 (quite) on 10 – 13 April 2026. The TEC was below 120 TECU over the last three days. Both are observed over Pontianak.

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

Navigation

Based on TEC, the error of the single-frequency GPS positioning on April 10th, 04:00 UT - April 11th, 03:59 UT was at a normal level. 
Based on TEC, the error of the single-frequency GPS positioning on April 11th, 04:00 UT - April 12th, 03:59 UT was at a normal level. 
Based on TEC, the error of the single-frequency GPS positioning on April 12th, 04:00 UT - April 13th, 03:59 UT was at a normal level.

Based on ionospheric scintillation and TEC variation, the probability of error positioning in the next 24 hours is predicted at a normal level.

HF Radio Communication

MUF depression was in a quiet condition, and Short Wave Fadeout (SWF) was at a quiet level on April 10th, 04:00 UT - April 11th, 03:59 UT.
MUF depression was in a moderate condition, and Short Wave Fadeout (SWF) was at a minor level on April 11th, 04:00 UT - April 12th, 03:59 UT.
MUF depression was in a quiet condition, and Short Wave Fadeout (SWF) was at a quiet level on April 12th, 04:00 UT - April 13th, 03:59 UT.

The MUF depression in the next 24 hours is predicted at a quiet level, due to the previous geomagnetic activity.
The SWF for the next 24 hours is predicted at a quiet level due to the prediction of the solar flare.
 

Satellites

The electron flux was at a high level on 10 April 2026 07UT - 11 April 2026 07UT.
The electron flux was at a high level on 11 April 2026 07UT - 12 April 2026 07UT.
The electron flux was at a high level for the last 24 hours.

A high level of electron flux is expected for the next 24 hours.

The flux of high-energy protons for April 10th, 2026 04:00 UT - April 11th, 2026 03:59 UT was quiet,
The flux of high-energy protons for April 11th, 2026 04:00 UT - April 12th, 2026 03:59 UT was quiet,
The flux of high-energy protons for April 12th, 2026 04:00 UT - April 13th, 2026 03:59 UT was quiet,
This quiet condition is predicted to continue for the next 24 hours.