Indices solaires, géomagnétiques et alertes HF

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Cette page présente les indices géomagnétiques et solaires, ainsi que les alertes du Space Weather Prediction Center (NOAA – USA) en vigueur actuellement.
Pour plus d’information sur ces alertes, visitez : http://www.swpc.noaa.gov/noaa-scales-explanation.

Messages émis par le NOAA/Space Weather Prediction Center
Mise à jour : 06/12/2025 21:33:02 UTC
Il y a actuellement 11 message(s) (dont 6 alerte(s) et 10 message(s) encore actif(s) au SWPC)
ALERT : Type II Radio Emission   04/12/2025 03:03:00 UTC   > Détails
Impact terrestre : 09/12/2025 03:13:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1450 Issue Time: 2025 Dec 04 0303 UTC ALERT: Type II Radio Emission Begin Time: 2025 Dec 04 0246 UTC Estimated Velocity: 345 km/s Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event. Fermer
WARNING : Geomagnetic K-index of 4 expected   06/12/2025 02:06:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5174 Issue Time: 2025 Dec 06 0206 UTC WARNING: Geomagnetic K-index of 4 expected Valid From: 2025 Dec 06 0205 UTC Valid To: 2025 Dec 06 1200 UTC Warning Condition: Onset www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer
ALERT : Geomagnetic K-index of 4   06/12/2025 02:58:00 UTC   > Détails
n/a
Space Weather Message Code: ALTK04 Serial Number: 2613 Issue Time: 2025 Dec 06 0258 UTC ALERT: Geomagnetic K-index of 4 Synoptic Period: 0000-0300 UTC Active Warning: Yes www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer
WARNING : Geomagnetic K-index of 5 expected   06/12/2025 08:37:00 UTC   > Détails
n/a
Space Weather Message Code: WARK05 Serial Number: 2148 Issue Time: 2025 Dec 06 0837 UTC WARNING: Geomagnetic K-index of 5 expected Valid From: 2025 Dec 06 0836 UTC Valid To: 2025 Dec 06 2359 UTC Warning Condition: Onset NOAA Scale: G1 - Minor www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Spacecraft - Minor impact on satellite operations possible. Aurora - Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine. Fermer
WARNING : EXTENDED Geomagnetic K-index of 4 expected   06/12/2025 08:52:00 UTC   > Détails
n/a
Space Weather Message Code: WARK04 Serial Number: 5175 Issue Time: 2025 Dec 06 0852 UTC EXTENDED WARNING: Geomagnetic K-index of 4 expected Extension to Serial Number: 5174 Valid From: 2025 Dec 06 0205 UTC Now Valid Until: 2025 Dec 06 2359 UTC Warning Condition: Persistence www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact primarily poleward of 65 degrees Geomagnetic Latitude. Induced Currents - Weak power grid fluctuations can occur. Aurora - Aurora may be visible at high latitudes such as Canada and Alaska. Fermer
ALERT : CONTINUED Electron 2MeV Integral Flux exceeded 1000pfu   06/12/2025 12:34:00 UTC   > Détails
n/a
Space Weather Message Code: ALTEF3 Serial Number: 3572 Issue Time: 2025 Dec 06 1234 UTC CONTINUED ALERT: Electron 2MeV Integral Flux exceeded 1000pfu Continuation of Serial Number: 3571 Begin Time: 2025 Dec 05 1530 UTC Yesterday Maximum 2MeV Flux: 1426 pfu Potential Impacts: Satellite systems may experience significant charging resulting in increased risk to satellite systems. Fermer
ALERT : X-Ray Flux exceeded M5   06/12/2025 20:41:00 UTC   > Détails
n/a
Space Weather Message Code: ALTXMF
Serial Number: 504
Issue Time: 2025 Dec 06 2041 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2025 Dec 06 2037 UTC
NOAA Scale: R2 - Moderate
www.swpc.noaa.gov/noaa-scales-explanation
Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see http://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap.

ALERT : Type II Radio Emission   06/12/2025 20:51:00 UTC   > Détails
Impact terrestre : 08/12/2025 09:01:00 UTC
Space Weather Message Code: ALTTP2 Serial Number: 1451 Issue Time: 2025 Dec 06 2051 UTC ALERT: Type II Radio Emission Begin Time: 2025 Dec 06 2040 UTC Estimated Velocity: 1143 km/s Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event. Fermer
SUMMARY : 10cm Radio Burst   06/12/2025 20:54:00 UTC   > Détails
n/a
Space Weather Message Code: SUM10R Serial Number: 892 Issue Time: 2025 Dec 06 2054 UTC SUMMARY: 10cm Radio Burst Begin Time: 2025 Dec 06 2035 UTC Maximum Time: 2025 Dec 06 2036 UTC End Time: 2025 Dec 06 2039 UTC Duration: 4 minutes Peak Flux: 1100 sfu Latest Penticton Noon Flux: 200 sfu Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications. Fermer
SUMMARY : X-ray Event exceeded M5   06/12/2025 20:57:00 UTC   > Détails
n/a
Space Weather Message Code: SUMXM5 Serial Number: 301 Issue Time: 2025 Dec 06 2057 UTC SUMMARY: X-ray Event exceeded M5 Begin Time: 2025 Dec 06 2029 UTC Maximum Time: 2025 Dec 06 2039 UTC End Time: 2025 Dec 06 2049 UTC X-ray Class: M8.1 Optical Class: 2b Location: N20E01 NOAA Scale: R2 - Moderate www.swpc.noaa.gov/noaa-scales-explanation Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth. Radio - Limited blackout of HF (high frequency) radio communication for tens of minutes. Fermer
ALERT : Type IV Radio Emission   06/12/2025 21:07:00 UTC   > Détails
n/a

Space Weather Message Code: ALTTP4
Serial Number: 698
Issue Time: 2025 Dec 06 2107 UTC

ALERT: Type IV Radio Emission
Begin Time: 2025 Dec 06 2057 UTC
Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

Conditions HF, indices solaires et géomagnétiques et historique quotidien
La plupart de ces données sont mises à jour en temps réel.

Conditions HF
NOAA Scale Activity
G0
n/a
R0
HF Bands Noise Level
S1-S2
Indices bruts
SFI
194
SSN
133
Ap
16
Kp
2
Kp Lat.
62,4°
X-Ray (HAF)
C1,8 (7,43 MHz)
Protons E>10 MeV
0,16
Electrons >2MeV
1 170,0
304A (SOHO)
0
304A (SDO/EVE)
376,0
Solar Wind (km/s)
639,5
Proton Density (p/cc)
1,8
Ion Temperature (°K)
259 000,0
IMF Bt (nT)
5,9
IMF Bz (nT)
0,1
Prévisions d'activité géomagnétique polaire (Auroral activity) à 30 minutes
North auroral activity
5 (HPI=13)
Impact as low as
62,5°
Expected in
-7 min.
Data source
NOAA SWPC
South auroral activity
5 (HPI=13)
Impact as low as
62,5°
Expected in
-7 min.
Data source
NOAA SWPC
Mise à jour des indices : 06/12/2025 21:32:02 UTC
Historique des indices pour la journée

Cette page réunit de nombreux indices solaires et terrestres. Ces données sont issues des satellites défilants (TIROS n – NOAA), géostationnaires (GOES – NOAA), ainsi que des satellites SOHO (NASA/ESA) et SDO/EVE (NASA). Les données de flux solaire proviennent quant à elles de l’observatoire de Penticton (CA).
Certaines valeurs sont des moyennes calculées sur les 15 dernières minutes (Bt et Bz), le flux solaire est publié à 17:00, 21:00 et 23:00 (UTC). Les autres sont des valeurs en temps réel (ou presque).
Une juxtaposition des données historisées de cette page et de l’historique de réception de FAROS est disponible sur cette page.

Merci à Paul, N0NBH pour son aide et sa patience (son site est très intéressant : www.hamqsl.com)

Plus d’infos sur ces indices :
– NOAA Space Weather Scales – http://www.swpc.noaa.gov/NOAAscales
– NOAA Tips on viewing the Aurora – http://www.swpc.noaa.gov/products/aurora-30-minute-forecast

Références :
– HF Ionospheric Radio Signal Propagation (en) http://www.radio-electronics.com/info/propagation/ionospheric/hf-propagation-basics.php
– Glossaire du SWPC de la NOAA (en) : http://legacy-www.swpc.noaa.gov/info/glossary.html
– What the data means – Scott Bidstrup, W7RI (en) http://www.bidstrup.com/w7ri-hf-radio-propagation.htm
– Understanding HF Radio Propagation Forecasts, N0HR (en) : http://www.n0hr.com/radio_propagation.htm
– Ionosphere Properties and Behaviors – Marcel H. De Canck ON5AU, AntenneX n°110 / Juin 2006 (en) : www.antennex.com (site hors ligne, essayez la « wayback machine »…)
– Ham-Bands propagation properties – Marcel H. De Canck ON5AU, AntenneX n°142 / Février 2009 (en) : www.antennex.com (site hors ligne, essayez la « wayback machine »…)