E' avvenuta oggi ed ha provocato provocato un black out in HF intorno alle 14.30 UTC .
A questo indirizzo potete vedere un " filmato dell' evoluzione " del fenomeno in funzione della attenuazione in HF alle varie frequenze .
https://www.swpc.noaa.gov/products/d-region-absorption-predictions-d-rap
di seguito l'immagine del massimo :
Da: SWPC
Product Subscription Service [mailto:SWPC.Products@noaa.gov]
Inviato: sabato 3 luglio 2021 16:35
A: reclaudio@alma.it
Oggetto: ALERT: X-ray Flux exceeded M5 (R2)
Space Weather Message Code: ALTXMF
Serial Number: 274
Issue Time: 2021 Jul 03 1434 UTC
ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2021 Jul 03 1427 UTC
NOAA Scale: R2 - Moderate
NOAA Space Weather Scale descriptions can be found at
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.
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