The 10.7 centimeter solar flux index (SFI) jumped to a Cycle 24 record of 262 on January 4, suggesting that Cycle 24 has not yet begun drawing to a close and may be approaching or at a “second peak.” The previous peak for the current cycle was 190 on September 24, 2011. As NASA’s Marshall Space Flight Center (MSFC) explains, the flux of the sun’s radio emissions at 10.7 centimeter (2.8 GHz) is …
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