Propagation Trends 2013-2014
Dayton 2013 1
Solar Maximum !A Double Peaked Sunspot Cycle ?
Every 6 Meter DXer Remembers This! The Second Sunspot Peak of Solar Cycle 23
Dayton 2013
400 Years of Sunspot Observations60 years of high sunspot cycleshave probably come to an end
Dayton 2013
70 years
40 years
Solar Cycle 24compared to all solar cycles since 1944
Dayton 2013
Cycle 24
the lowest solar minimum in 100 yearsfollowed by the lowest solar cycle in 100 Years
Sunspot Cycle 24 ProgressActual vs. Prediction
http://solarscience.msfc.nasa.gov/images/ssn_predict_l.gif
5
Prediction
Sun
spot
Num
ber
Actual
Solar Cycle 24 Prediction compared to similar Solar Cycle 14
Dayton 2013
two years between Solar Cycle 14 peaks
many solar scientists expect a double peaked
Solar Cycle 24
Why are there Often
Double Sunspot Cycle Peaks?
Dayton 2013
solar northern and southern hemisphere sunspot cycle peaks never occur at the same time
Sun
spot
Num
ber
Solar Cycle 24 is similar to Cycle 14the solar southern hemisphere sunspot peak occurred two years after the northern hemisphere sunspot peak
Dayton 2013
two years between sunspot peaks
N S
southern hemisphere sunspots started to increase one year after the northern hemisphere sunspot
peak
Sun
spot
Gro
ups
per M
onth
The Last Two Solar Cycles also had Double Peaksbut very different than weaker Solar Cycle 24
Dayton 2013
two years between sunspot peaks two years between
sunspot peaks
NN
SS
southern hemisphere sunspots started to increase one year after the northern hemisphere sunspot
peak
Sunspot Production has Slowed in Both Solar Hemispheres
Dayton 2013
northern hemispheresunspot production
slowed after peaking in Sep - Dec
2011
southern hemispheresunspot production
slowed after peaking in Jun - Jul 2012
SN
Sun
spot
Gro
ups
per M
onth
southern hemisphere sunspot production continues tolag behind northern hemisphere sunspot production
?
Solar North-South Polar Field Reversalsolar maximum usually occurs when
both polar fields have reversed polarity
Dayton 2013
2012 2013
north polefield reversal in June 2012(smoothed)
south pole field strength is very slowly decreasingDec 2012 – Mar 2013
field reversal
north pole field strengthcontinues to slowly
increaseJuly 2012 – Mar 2013
Jan Jan
smoo
thed
pol
ar fi
eld
stre
ngth
mic
ro-T
esla
the south polar field is progressing very slowly toward field
reversal
S
N
Weak Solar Cycle 24 has been Unusually Favorable for 160 and 80 Meters
The A-index has been much lower than normal
Dayton 2013
two years between Solar Cycle 23 peaks
the A index usually increases during the first two years
after solar maximum
The A-Index may increase moderately after Solar Cycle 24 maximum
unusually low A index
A Long Range Estimate of Solar Cycle 25are sunspots disappearing?
http://myweb.wwu.edu/dbunny/pdfs/Solar-Cycle-25-Amplitude-estimate.pdf
some solar scientists expect Cycle 25 to be the weakest solar cycle in 400 years
http://www.landscheidt.info/?q=node/280