Het archief bekijken van dinsdag 18 augustus 2026

Dagelijks bulletin over zonne- en geomagnetische activiteit van het SIDC

Datum verslag: 2026 Aug 18 1231 UTC

SIDC Prognose

Zonnevlammen

C-class flares expected, (probability >=50%)

Geomagnetisme

Active conditions expected (A>=20 or K=4)

Proton Flux monitor

Quiet

	10cm flux	Ap
18 Aug 2026	126	019
19 Aug 2026	122	024
20 Aug 2026	115	027

Zonnevlekkengebieden en zonnevlammen

Solar flaring activity was low over the past 24 hours, with only C-class flares identified. The largest flare was a C3.9 flare (SIDC Flare 8384), peaking at 06:43 UTC on August 18, which was associated with SIDC Sunspot Group 940 (NOAA Active Region 4507, magnetic type beta-gamma-delta). There are currently four numbered active regions on the solar disk. SIDC Sunspot Group 940 (NOAA Active Region 4507) is the most complex group and grew over the past 24 hours. SIDC Sunspot Groups 939 and 943 (NOAA Active Regions 4506 and 4510, magnetic types beta-gamma and beta, respectively) are approaching the west limb. The solar flaring activity is expected to be low over the next 24 hours, with C-class flares very likely and a chance for M-class flares.

Coronale massa uitstoten

No Earth-directed Coronal Mass Ejections (CMEs) were observed in the available coronagraph imagery in the last 24 hours.

Coronale gaten

A northern mid-latitude, negative polarity coronal hole (SIDC Coronal Hole 142) started crossing the central solar meridian during the past 24 hours. An associated high-speed stream may arrive at Earth starting from August 21.

Zonnewind

Over the past 24 hours, the solar wind parameters reflected slightly perturbed solar wind conditions. Speed values were initially around 300 km/s and gradually increased to around 420 km/s. The interplanetary magnetic field values ranged between 3 nT and 15 nT. The Bz component varied between -12 nT and 9 nT. The interplanetary magnetic field angle showed variable sector orientation, with a switch from mostly negative to mostly positive values during the later part of the period. These conditions are likely related to a mild glancing blow associated with the partial halo Coronal Mass Ejection (SIDC CME 707), observed in LASCO/C2 coronagraph imagery starting from around 07:12 UTC on August 14. Further enhancements in the solar wind parameters are possible over the next 24 hours due to the possible arrival of a high-speed stream from the negative polarity coronal hole (SIDC Coronal Hole 149), which crossed the central meridian early on August 16.

Geomagnetisme

Geomagnetic conditions globally were initially quiet to unsettled, becoming mostly active from 18:00 UTC on August 17 onwards, with one interval of minor storm conditions between 03:00 UTC and 06:00 UTC on August 18 (NOAA Kp 5). Locally, geomagnetic conditions were mostly unsettled, with active conditions observed between 20:00 UTC and 23:00 UTC on August 17 (K BEL 4). Mostly unsettled to active geomagnetic conditions are expected over the next 24 hours, with possible isolated minor storm intervals due to the possible continued influence of the mild glancing blow associated with SIDC CME 707 and the possible arrival of a high-speed stream from the negative polarity coronal hole (SIDC Coronal Hole 149).

Proton flux niveaus

The greater than 10 MeV proton flux was below the 10 pfu threshold level over the past 24 hours. It is expected to remain below the threshold level over the next 24 hours.

Elektronenfluxen in geostationaire baan

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was below the 1000 pfu threshold in the last 24 hours. The greater than 2 MeV electron flux is expected to be below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence is presently at normal levels and is expected to remain so over the next 24 hours.

Het geschatte internationale zonnevlekkengetal (ISN) van vandaag: 073, gebaseerd op 12 stations.

Zon indexen voor 17 Aug 2026

Wolfgetal Catania	///
10cm zonneflux	124
AK Chambon La Forêt	///
AK Wingst	014
Geschatte Ap	013
Geschat internationaal zonnevlekkengetal	085 - Gebaseerd op 25 stations

Overzicht opvallende gebeurtenissen

Aangeboden door het Solar Influences Data Analysis Center© - SIDC - Verwerkt door SpaceWeatherLive

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