• A brief history of past solar cycles• Analysis of Cycle 24 – The present• Where we are headed with DXing

Radio PropagationRadio Propagation

The Sun : DXers Enemy or The Sun : DXers Enemy or Friend?Friend?

Actually – The Sun is a bit of Actually – The Sun is a bit of both!both!

What allows us to work What allows us to work DX?DX?• First and Foremost - Our Operating Skills!First and Foremost - Our Operating Skills!

The Sun ionizes the earth’s earth’s The Sun ionizes the earth’s earth’s IonosphereIonosphere and allows us to bounce and allows us to bounce

signals around the planetsignals around the planet

• And second - our very moody Sun!And second - our very moody Sun!

Why is Ionization a good thing?No Ionization = No refraction of HF signals off the Ionosphere D and E and F Layers = Little or no DX

The Sun can be The Sun can be quite benign at timesquite benign at times

And the Sun can And the Sun can get get

very, very Angry!!very, very Angry!!

Great DXing depends on the moody SunGreat DXing depends on the moody Sun

SSN & SFISSN & SFI It’s how we measure where the sun is at!It’s how we measure where the sun is at!

SSN - Sun Spot Number

Higher sunspot numbers indicate increasing Ionization which results in better refraction of HF signals off the Ionosphere

SFI – Solar Flux Index

The Solar Flux value is actually a measurement of radio signals from the sun. The index is measured once a day at 2800 Mhz (10.7 cm) Increased radio noise from the sun results in more ionizing radiation of earth’s Ionosphere.

Solar Flux ranges from 60 (No Sunspots) to 300 (Work DX 24/7!!!)

And now – A little history of what our And now – A little history of what our sun has been doing for the past 400 sun has been doing for the past 400

yearsyears

Minimums,

Maximums,

Peaks,

and Troughs.

It’s Solar violence in the extreme!

Past Solar CyclesPast Solar Cycles

Sunspots were rarely observed during the Maunder Minimum in the 17th century. This coincides with the period of cooling known as the Little Ice Age.

Sunspot populations quickly rise and more slowly fall on an irregular cycle of 11 years. From 1900 to the 1960s the solar maxima trend of sunspot count has been upward; from the 1960s to the present, it has diminished somewhat.

Sunspot Cycles – Every 11 Years

Sunspot Cycles are Notoriously Difficult to Accurately Predict. 

Solar physicists believe the massive circulating current of hot plasma within the Sun predicts the amplitudes of sunspot cycles approximately 20 years into the future. In the years prior to 2006 that speed had become lower than ever before observed.

The National Center for Atmospheric Research predicted Cycle 24 would be intense. NASA predicted Cycle 25 will be extraordinarily weak. The NCAR prediction for Cycle 24 is shown

above in pink. NASA's Cycle 24 and 25 predictions are shown in red. Both were wrong!

Cycle 24 on it’s way to 2014 PeakCycle 24 on it’s way to 2014 Peak ( 2012 SSN Prediction )( 2012 SSN Prediction )

Cycle 24 SSN - What actually happenedCycle 24 SSN - What actually happened

Many cycles are double peaked but this is the first in which the second peak in sunspot number was larger than the first.

Cycle 24Cycle 24 - December 2014- December 2014The Weirdest cycle yet!The Weirdest cycle yet!

Cycle 24 is the lowest smoothed-count sunspot cycle since Cycle 14 which peaked at 64.2 in February 1906.

What is the Sun doing today?What is the Sun doing today?

The are are 70 sunspots on the The are are 70 sunspots on the surfacesurface (SSN)(SSN)

The IndexThe Index (SFI)(SFI) isis 126 .126 .TheThe AA and and KK Indexes are pretty Indexes are pretty low.low.

Conditions are average – NOT Conditions are average – NOT spectacular!spectacular!

These updated charts are on most These updated charts are on most amateur radio websitesamateur radio websites

Propagation for Working DX – Space WeatherPropagation for Working DX – Space Weather

• Needed long-term solar flux or sunspot number for F2 openings

– 6-Meters: SFI > 200 or ssn > 100

– 10-Meters: SFI > 100 or ssn > 50

– 12-Meters: SFI > 75 or ssn > 35

– 15-Meters: SFI > 50 or ssn > 25

• 17-Meters and 20-Meters generally open throughout a solar cycle

– May be restricted to daylight hours

– Low bands not dependent on MUF

– Ap index less than 7 indicates quiet geomagnetic field

– Over the pole paths (high lat) the best

The Big Picture – SFI, SSN, Ap

The “A” IndexThe “A” Index

The “K” IndexThe “K” Index

How does Radio Propagation How does Radio Propagation work for us during the day and work for us during the day and during the night? during the night?

Answer: It depends on the Answer: It depends on the Sunspot activity and the time of Sunspot activity and the time of day or night.day or night.

Understand what happens and Understand what happens and you can make propagation work you can make propagation work for youfor you

Returning to Day / Night Propagation

No Ionization = No refraction of HF signals off the Ionosphere D and E and F Layers = Little or no DX

The Sunspots are up...... The Sunspots are up......

The SFI is raging....... The SFI is raging.......

You are working DX 24/7 and You are working DX 24/7 and can't believe your luck!!!!!can't believe your luck!!!!!

And then – along comesAnd then – along comes

the dreaded the dreaded CMECME

CME CME ????????????

A A CMECME is a Coronal Mass Ejection event is a Coronal Mass Ejection eventwhich will generate X-Rays and giant which will generate X-Rays and giant

clouds of solar material and solar winds clouds of solar material and solar winds

A A CMECME is a Solar “Event” is a Solar “Event”

Events occur more often during 11 year Events occur more often during 11 year

peakspeaks

Radio disruption can be major or minorRadio disruption can be major or minor

Only the Sun knows when it will happen.Only the Sun knows when it will happen.

Solar Flares

A flare can reach earth at the speed of lightin 8 minutes with magnetic energy and X-Rays

And what can you do about a big flare?Very little.... but you can still work DX!

Move to a lower band – 80M, 160M

Move to a higher band – 2M, 70Cm 23 Cm

Take up the black art of EME radio

Wait it out. Conditions will return to

whatever “Normal” is :-)

What is our future for working DX!

1 Year out: – SFI noticeably lower and quieter band activity. There will still be Dxpeditions and rare countries on offer

3 Years out: - SFI languishing below 100 (70 -90s)

6 Years out: - Sunspot activity zero and SFI around 60. You are trying to sell your 6m gear!

11 Years out: - Cycle 25 peak. It will be a non-event and the lowest level of activity since the 1800s. You will be depressed!

Doing it Hard during a Solar MinimumDoing it Hard during a Solar Minimum(Hmmmm - He could always try “670”)(Hmmmm - He could always try “670”)