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 years

followed by the lowest solar cycle in 100 years

Solar Cycle 24 ProgressActual vs. Prediction

http://solarscience.msfc.nasa.gov/images/ssn_predict_l.gif

5

Sun

spot

Num

ber

PredictionActual

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 Solar Cycle Peaks?

Dayton 2013

solar northern and southern hemisphere solar 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 June - July 2012

SN

Sun

spot

Gro

ups

per M

onth

southern hemisphere sunspot production continues tolag behind northern hemisphere sunspot production

?

Progress of Solar Cycle 24Northern and Southern Hemispheres

Dayton 2013

Solar North-South Polar Field Reversalsolar maximum usually occurs when

both polar fields have reversed polarity

Dayton 2013

Series1

-20-16-12-8-40481216202428323640

2012 2013

north polar field reversed in June 2012 (smoothed)

south polar field strength is very, very slowly decreasing

Dec 2012 – May 2013

field reversal

north polar field strength is slowly increasing

July 2012 – May 2013

Jan Jan

smoo

thed

pol

ar fi

eld

stre

ngth

mic

ro-T

esla

progress of south polar field reversalis exceptionally slow

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

Solar Cycle 23 double 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