Thursday, 18 December 2014

Waiting For The Magic

Courtesy: http://www.noaa.gov/
Somewhat disheartening Cycle 24 never fails to surprise us with its unexpected behaviour and this week is no exception. A week ago, the solar flux was sitting at an uninspiring 138 but has gradually been rising because of the recent growth in new sunspots. At noon today, the flux had reached a level of 219...one of the highest levels of this cycle! With such high numbers, 6m junkies are understandably growing fidgety and watching the rising MUF with hopes that it may reach that magic number of 50MHz.

The last time the sun did this, at the end of November, I was able to work two stations in Florida on F2 during a short surge in the MUF that had been hovering in the 46-47MHz range. Maybe we'll all get lucky again soon if solar activity continues to climb.


Courtesy: http://www.noaa.gov/
Once the geomagnetic field can stabilize for a few days, with high flux, we should see the MUF begin to rise again....tomorrow hopefully. The constant flaring (over a dozen flares in the past two days) and the impending arrival of an earlier CME, may be all that we need. Any auroral event will likely cause a very good spike in the F2 MUF the following day. An excellent short article on Understanding Solar Indices by G3YWX may be found here.

Today's rise in the MUF was a disappointment as the highest I saw was about 43MHz, for a brief few moments. The MUF then dropped back below 37MHz but continued to surge into the high 39's.

This short video, made today at around noon, shows the MUF surging....the band full of signals one moment and then empty the next. The region between 10m and 6m is chalk-full of commercial FM activity (police, fire, utility, etc) and makes and excellent way of monitoring the trend in MUF growth...at times it seems that the F layer is alive and breathing as it tries, usually without success, to climb higher and higher. One of stations in the video appears to be from Maryland, on the typical E-W propagation path seen at this time of the year. My receiving antenna is my normal 4-el 6m Yagi, which must be horribly inefficient at this frequency yet...notice how strong signals can be when they are propagating right at the edge of the MUF:


 
So... hang onto your hats boys....it could be an exciting week yet!

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