ARRL

Search for Amateur Radio News

  • Sunspot040810

    04/09/2010 | The K7RA Solar Update

    A strong geomagnetic storm on Monday and Tuesday -- April 5-6 -- was the biggest since 2006, at least in terms of high planetary A index. On those days, the mid-latitude A index was 28 and 22 and the planetary A index was 49 and 46. This was caused by a m
    Learn More

  • sunspot012910

    01/29/2010 | The K7RA Solar Update

    Recent sunspot activity is increasing, and the numbers bear this out.
    Learn More

  • 01/02/2009 | The K7RA Solar Update

    2008 was a year of very low solar activity. More than 40 percent of this year's propagation bulletins reported zero sunspots for their respective weeks. The average daily sunspot number for the year was 4.7; in 2007, it was 12.8. The yearly averages of da
    Learn More

  • 04/25/2008 | The K7RA Solar Update

    This week we had a couple of brief sunspot appearances -- 991 and 992 -- but they were both from Solar Cycle 23 and their emergence was fleeting. On Wednesday, April 23, the planetary A index rose to 32 due to a solar wind and south-pointing Interplanetar
    Learn More