pvrc webinar 18 & 21july 2012 k9la cycle 24 status – and much more carl luetzelschwab k9la...

PVRC Webinar 18 & 21July 2012 PVRC Webinar 18 & 21July 2012 K9LAK9LA

Cycle 24 Status – and Much Cycle 24 Status – and Much MoreMore

Carl Luetzelschwab K9LACarl Luetzelschwab [email protected]@arrl.net

11


TopicsTopics• Quick review of August 2009 presentationQuick review of August 2009 presentation• Recent dataRecent data

– Solar min reviewSolar min review– Cycle 24 statusCycle 24 status– Cycle 24 looking aheadCycle 24 looking ahead

• Seasonal effects on propagationSeasonal effects on propagation• Four relevant Cycle 24 questionsFour relevant Cycle 24 questions• Two other topicsTwo other topics

– Effect of treesEffect of trees– Best height for an antennaBest height for an antenna

22

Quick review of August 2009 Quick review of August 2009 presentationpresentation

PVRC Webinar 18 & 21July 2012 PVRC Webinar 18 & 21July 2012 K9LAK9LA 33

August 2009 WebinarAugust 2009 Webinar

We were at solar min – how long would it last?We were at solar min – how long would it last?


02

468

10

12141618

2022

0 5 10 15 20 25 30 35 40

months from descent below smoothed sunspot number of 20

sm

oo

the

d s

un

sp

ot

nu

mb

er between Cycles 18 and 19

(Apr 1954)

between Cycles 19 and 20(Nov 1964)

between Cycles 20 and 21(Jun 1976)

between Cycles 21 and 22(Sep 1986)

between Cycles 22 and 23(Oct 1996)

between Cycles 23 and 24

44



From Dr. David Hathaway (MSFC, 2009)

• We’d been seeing Cycle 24 sunspots for about a year We’d been seeing Cycle 24 sunspots for about a year and a halfand a half

• But Cycle 24 hadn’t started ramping up yetBut Cycle 24 hadn’t started ramping up yet

55



• Prior to this July Prior to this July 2009 prediction, 2009 prediction, ISES had been ISES had been carrying two carrying two predictionspredictions• One for a One for a

“high” cycle “high” cycle (140)(140)

• One for a “low” One for a “low” cycle (90)cycle (90)

• Long duration solar Long duration solar minimum led to minimum led to decision to go with decision to go with “low” cycle “low” cycle predictionprediction

66

International Space Environment Service


Most recent Most recent datadata

77


Recent Solar MinimumsRecent Solar Minimums

Longest of our lifetimesLongest of our lifetimes

0

2

4

6

8

10

12

14

16

18

20

22

1 6 11 16 21 26 31 36 41 46 51 56

months from descent below a smoothed sunspot number of 20

smo

oth

ed s

un

spo

t n

um

ber

between Cycles 18 and 19(min Apr 1954)

between Cycles 19 and 20(min Nov 1964)

between Cycles 20 and 21(min Jun 1976)

between Cycles 21 and 22(min Sep 1986)

between Cycles 22 and 23(min Oct 1996)

between Cycles 23 and 24(min Dec 2008)

88


All Solar MinimumsAll Solar Minimums

We’ve had similar minimums – even longer minimumsWe’ve had similar minimums – even longer minimums(assuming our data is good back then)(assuming our data is good back then)

0

20

40

60

80

100

120

1-2

2-3

3-4

4-5

5-6

6-7

7-8

8-9

9-10

10-1

111

-12

12-1

313

-14

14-1

515

-16

16-1

717

-18

18-1

919

-20

20-2

121

-22

22-2

323

-24

sola r m inim um be tw e e n indic a te d c yc le s

nu

mb

er o

f m

on

ths

bel

ow

a

smo

oth

ed s

un

spo

t n

um

ber

of

20 Average duration ~ 37 months

99


Next Max vs Previous Solar Next Max vs Previous Solar MinMin

Looks like we’re headed for a small cycleLooks like we’re headed for a small cycle

Next Solar Max vs Duration of Previous Solar Min

R2 = 0.5815

0

50

100

150

200

250

10 20 30 40 50 60 70 80 90 100

months at solar minimum (smoothed sunspot number < 20)

max

imu

m s

mo

oth

ed

sun

spo

t n

um

ber

of

nex

t so

lar

cycl

e

1010


First Sunspot of Cycle 24First Sunspot of Cycle 24

1111


Current Cycle 24 DataCurrent Cycle 24 Data

• Solar min around December 2008Solar min around December 2008• Cycle 24 slow to start its ascentCycle 24 slow to start its ascent• Have we reached Cycle 24’s peak or is this just a temporary lull?Have we reached Cycle 24’s peak or is this just a temporary lull?

1212

0

10

20

30

40

50

60

70

80

90

100

J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N

2006 2007 2008 2009 2010 2011 2012

Su

nsp

ot

Nu

mb

er

Cycle 24 monthly mean

Cycle 23 monthly mean

smoothed


In Terms of 10.7 cm Solar In Terms of 10.7 cm Solar FluxFlux

1313

Solar Min Between Cycle 23 and 24 and Cycle 24 Ascentin terms of 10.7 cm solar flux

60

70

80

90

100

110

120

130

140

150

160

J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N J M M J S N

2006 2007 2008 2009 2010 2011 2012

10.7

cm

S

ola

r F

lux

monthly mean smoothed

Similar trends


Geomagnetic Field ActivityGeomagnetic Field Activity

• Still quieter than 1996 solar minimum – too quiet?Still quieter than 1996 solar minimum – too quiet?• Where is 160-Meters?Where is 160-Meters?

– Are we seeing the effect of galactic cosmic rays?Are we seeing the effect of galactic cosmic rays?

1414

Smoothed Sunspot Number and # of Days in Month With Ap < 7Cycle 21 decline through Cycle 24 Ascent

0

40

80

120

160

200

Jan

-82

Jan

-84

Jan

-86

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

Jan

-10

Jan

-12

Month, Year

sm

oo

the

d s

un

sp

ot

nu

mb

er

0

6

12

18

24

30

# d

ay

s in

mo

nth

wit

h A

p

< 7


Cycle 24 vs Cycle 23Cycle 24 vs Cycle 23

• For a short time Cycle 24 rate of ascent was comparable to Cycle 23For a short time Cycle 24 rate of ascent was comparable to Cycle 23• But Cycle 24 was slower to start – tends to indicate lower cycleBut Cycle 24 was slower to start – tends to indicate lower cycle

1515

C y c le 24 v s C y c le 23

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70 80 90 100

months after s olar minimum

smo

oth

ed s

un

spo

t n

um

ber

C yc le 23 C yc le 24

Current PredictionsCurrent Predictions


60

90

1616

International Space Environment Service Marshall Space Flight Center

A Very Early PredictionA Very Early Prediction


If only it were true!

1717


Seasonal Seasonal effectseffects

1818


Seasonal EffectsSeasonal Effects

• With the smoothed sunspot number With the smoothed sunspot number hovering around 60 (smoothed 10.7 cm hovering around 60 (smoothed 10.7 cm solar flux around 120) beginning in August solar flux around 120) beginning in August 2011, seasonal effects become noticeable 2011, seasonal effects become noticeable for 10m propagationfor 10m propagation

• Let’s look at the MUFs along two paths at a Let’s look at the MUFs along two paths at a smoothed sunspot number of 60smoothed sunspot number of 60– W3 to EU, to JA, and to S. AmericaW3 to EU, to JA, and to S. America– G to Eastern EU, to W4, and to JAG to Eastern EU, to W4, and to JA

1919


W3 to EUW3 to EU

• October thru December good for 10-MetersOctober thru December good for 10-Meters• Summer months worstSummer months worst

0

5

10

15

20

25

30

35

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

MH

z W3 to DL

28 MHz

2020


W3 to JAW3 to JA

• October best for 10-MetersOctober best for 10-Meters• Summer months worstSummer months worst

0

5

10

15

20

25

30

35


W3 to JA

28 MHz

2121


W3 to S AmericaW3 to S America

• September thru April good for 10-MetersSeptember thru April good for 10-Meters– Thanks to the robust equatorial ionosphereThanks to the robust equatorial ionosphere

• Summer months worstSummer months worst

0

5

10

15

20

25

30

35


W3 to LU

28 MHz

2222

G to Eastern EuropeG to Eastern Europe

• October thru February best for 10-MetersOctober thru February best for 10-Meters



0

5

10

15

20

25

30


MH

z G to LZ

28 MHz

G to W4G to W4

• October thru February good for 10-MetersOctober thru February good for 10-Meters



0

5

10

15

20

25

30

35


G to W4

28 MHz

G to JAG to JA

• October best for 10-MetersOctober best for 10-Meters



0

5

10

15

20

25

30

35


G to JA

28 MHz


Last Fall vs This SpringLast Fall vs This Spring

• Decrease in monthly mean solar activity Decrease in monthly mean solar activity resulted in leveling off of the smoothed resulted in leveling off of the smoothed valuevalue

• As we moved from Fall/Winter to the As we moved from Fall/Winter to the Spring, seasonal effects came into playSpring, seasonal effects came into play

• In general, 10-Meters for CQ WW and ARRL In general, 10-Meters for CQ WW and ARRL 10M good, ARRL DX and CQ WPX not so 10M good, ARRL DX and CQ WPX not so goodgood

• This Fall – 10-Meters should be goodThis Fall – 10-Meters should be good• But we need a more active Sun to help But we need a more active Sun to help

with 10-Meter propagation next Spring!with 10-Meter propagation next Spring!2626


Four FAQsFour FAQs

2727


#1 - Two Peaks for Cycle #1 - Two Peaks for Cycle 24?24?

• Cycle 19, 20, and Cycle 19, 20, and 21 didn’t show 21 didn’t show much of a much of a second peaksecond peak

• Cycle 22 and 23 Cycle 22 and 23 did show a did show a definite second definite second peakpeak– Cycle 23’s Cycle 23’s

second peak second peak made 6-Meter made 6-Meter DXers very DXers very happy in the happy in the Winter of 2001Winter of 2001

Cycle 24 could have a second peak

2828


#2 - 6-Meter F#2 - 6-Meter F22??

• Paths not involving the equatorial Paths not involving the equatorial ionosphere are very unlikely with the ionosphere are very unlikely with the current Cycle 24 predictioncurrent Cycle 24 prediction• TEP is still possibleTEP is still possible

• If FIf F22 does happen away from the equator, does happen away from the equator, it would be most likely during the Spring, it would be most likely during the Spring, Fall, and Winter of 2013Fall, and Winter of 2013

• Sporadic E should still be thereSporadic E should still be there– Late morning and early evening in the Late morning and early evening in the

SummerSummer– Early evening in DecemberEarly evening in December

2929

Recent 6m Opening - W7 to Recent 6m Opening - W7 to EUEU

Probably not FProbably not F22 – most likely Es – most likely Es


29 June 2012

foF2 ~ 4.7 MHzF2 MUF ~ 17.4 MHz

foEs > 9.5 MHzEs MUF > 50 MHz

3030


#3 - Disappearing #3 - Disappearing Sunspots?Sunspots?

• W. Livingston and M. W. Livingston and M. Penn measured the Penn measured the maximum strength of maximum strength of magnetic fields of magnetic fields of sunspotssunspots

• Strength has been Strength has been declining since 1992declining since 1992

• Need about 1500 gauss Need about 1500 gauss for sunspots to be visiblefor sunspots to be visible

• Extrapolating their data Extrapolating their data says sunspots will says sunspots will disappear by 2016disappear by 2016

extrapolation

3131

2012 Update2012 Update


So what if sunspots disappear?

Remember that sunspots are a proxy for the true ionizing radiation (EUV), which still appears to be alive and well

3232

Slope the same as previous plot – vertical axis in this plot is expanded

Aug us t 1947 throug h D ec ember 2011(pe a k of C yc le 18 throug h sta rt of C yc le 24)

R 2 = 0.981

0.0

50.0

100.0

150.0

200.0

250.0

300.0

0 50 100 150 200 250sm oothe d sunspot num be r

smo

oth

ed 1

0.7

cm s

ola

r fl

ux

Sunspot Number vs Solar Sunspot Number vs Solar FluxFlux


If sunspots are disappearing, we might expect to see a decrease in the correlation of smoothed sunspot number and smoothed 10.7 cm solar flux

Aug us t 1947 throug h D ec ember 1996(pe a k of C yc le 18 throug h e nd of C yc le 22)

R 2 = 0.9908

0.0

50.0

100.0

150.0

200.0

250.0

300.0

0 50 100 150 200 250sm oothe d sunspot num be r

smo

oth

ed 1

0.7

cm s

ola

r fl

ux

Cycle 23/24 data

Also impacts propagation predictions using smoothed sunspot number


#4 - Another Maunder #4 - Another Maunder Minimum?Minimum?

• Maunder Minimum - lack Maunder Minimum - lack of sunspots from 1645-of sunspots from 1645-1715 1715

• The three cycles before The three cycles before Maunder Minimum Maunder Minimum showed a smooth showed a smooth decrease in group decrease in group sunspot numbersunspot number

• It’s generally agreed that the Sun is “slowing It’s generally agreed that the Sun is “slowing down”down”

• Cycles 22, 23, and 24 exhibit a smooth decrease, Cycles 22, 23, and 24 exhibit a smooth decrease, tootoo

• What Cycle 24 does and duration of solar min What Cycle 24 does and duration of solar min between Cycle 24 and 25 may suggest where between Cycle 24 and 25 may suggest where we’re headedwe’re headed

• It very well may be there will still be an ionosphereIt very well may be there will still be an ionosphere3434


Trees and HF Trees and HF propagationpropagation

3535

Trees and HF•All of my

antennas look through trees on headings from Northwest thru South

• Is this a problem?


Trees and HF – Two Issues

•Foliage (leaves)– Use the work of Tamir and Krevsky


Foliage• Conductivity

much more significant than permittivity

• Mid latitude woods – Minor effect at

LF– More effect as

frequency increases

• But my trees are deciduous – probably very minor effect in winter


Trunk (Chunk of Lossy Dieletric)

• Technical Correspondence, Nov 1991 QST

• 75m vertical in pine trees

• Distances

• High voltage portion too close to trunk

• Try to keep high voltage portion greater than .023 wavelengths from trunk

• These experiments were with wire parallel to tree trunk– Beverage antenna probably more forgiving



Best antenna Best antenna heightheight

4040

Best Height for Antenna

• Elevation statistics in the ARRL Antenna Book CD from N6BV’s work• Example: Indianapolis to six areas of the world and to the US

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

elevation angle, degrees

perc

etn

of th

e tim

e

EU JA AF SE Asia OC SA USA

Indianapolis to the world on 10-Meters


Antenna Patterns

5-element 10m monobander over average ground

0

5

1 0

1 5

2 0

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2

e le v a ti o n a n g le , d e g r e e s

pe

rce

tn o

f th

e ti

me

or

ga

in i

n

dB

i

5 -e l a t 2 5 ft 5 -e l a t 5 0 ft 5 -e l a t 1 0 0 ft


Elevation Statistics + Patterns

• Best “compromise” height is ~ 1.5 wavelengths (50 ft)– Agrees with W2PV’s analysis in his book Yagi Antenna Design

• Need to stack antennas to cover all the angles

0.0

5.0

10.0

15.0

20.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

elevation angle, degrees

perc

etn

of t

he ti

me

or g

ain

in d

Bi

all elevation angles 5-el at 25 ft 5-el at 50 ft 5-el at 100 ft



SummarySummary• Cycle 24 has leveled offCycle 24 has leveled off

– Is this temporary or are we at the peak?Is this temporary or are we at the peak?– Next several months will give us a clueNext several months will give us a clue

• Cycle 24 has a decent chance of two peaksCycle 24 has a decent chance of two peaks– Would likely prolong propagation on the higher bandsWould likely prolong propagation on the higher bands

• 6M F6M F22 propagation probably restricted to equatorial propagation probably restricted to equatorial ionosphereionosphere

• Sunspots may disappear, but EUV will likely still be thereSunspots may disappear, but EUV will likely still be there

• Too early to tell if we’re headed for another Maunder Too early to tell if we’re headed for another Maunder MinimumMinimum• Even if we are, maybe it doesn’t matter with respect to Even if we are, maybe it doesn’t matter with respect to

propagationpropagation

• Expect good 10-Meter contest season for CQ WW and ARRL Expect good 10-Meter contest season for CQ WW and ARRL 10M10M

• ARRL DX and CQ WPX next spring need more solar ARRL DX and CQ WPX next spring need more solar activityactivity

• Don’t worry too much about trees – especially in the winterDon’t worry too much about trees – especially in the winter

• Try to put your antenna at the “optimum” heightTry to put your antenna at the “optimum” height

4444

pvrc webinar 18 & 21july 2012 k9la cycle 24 status – and much more carl luetzelschwab k9la...

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