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PVRC Webinar 18 & 21July 2012 K9LA Cycle 24 Status – and Much More Carl Luetzelschwab K9LA 1.

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Presentation on theme: "PVRC Webinar 18 & 21July 2012 K9LA Cycle 24 Status – and Much More Carl Luetzelschwab K9LA 1."— Presentation transcript:

1 PVRC Webinar 18 & 21July 2012 K9LA Cycle 24 Status – and Much More Carl Luetzelschwab K9LA 1

2 PVRC Webinar 18 & 21July 2012 K9LA Topics Quick review of August 2009 presentation Quick review of August 2009 presentation Recent data Recent data –Solar min review –Cycle 24 status –Cycle 24 looking ahead Seasonal effects on propagation Seasonal effects on propagation Four relevant Cycle 24 questions Four relevant Cycle 24 questions Two other topics Two other topics –Effect of trees –Best height for an antenna 2

3 Quick review of August 2009 presentation PVRC Webinar 18 & 21July 2012 K9LA3

4 August 2009 Webinar We were at solar min – how long would it last? PVRC Webinar 18 & 21July 2012 K9LA4

5 August 2009 Webinar PVRC Webinar 18 & 21July 2012 K9LA From Dr. David Hathaway (MSFC, 2009) Wed been seeing Cycle 24 sunspots for about a year and a half Wed been seeing Cycle 24 sunspots for about a year and a half But Cycle 24 hadnt started ramping up yet But Cycle 24 hadnt started ramping up yet 5

6 August 2009 Webinar PVRC Webinar 18 & 21July 2012 K9LA Prior to this July 2009 prediction, ISES had been carrying two predictions Prior to this July 2009 prediction, ISES had been carrying two predictions One for a high cycle (140) One for a high cycle (140) One for a low cycle (90) One for a low cycle (90) Long duration solar minimum led to decision to go with low cycle prediction Long duration solar minimum led to decision to go with low cycle prediction 6 International Space Environment Service

7 PVRC Webinar 18 & 21July 2012 K9LA Most recent data 7

8 PVRC Webinar 18 & 21July 2012 K9LA Recent Solar Minimums Longest of our lifetimes 8

9 PVRC Webinar 18 & 21July 2012 K9LA All Solar Minimums Weve had similar minimums – even longer minimums (assuming our data is good back then) Average duration ~ 37 months 9

10 PVRC Webinar 18 & 21July 2012 K9LA Next Max vs Previous Solar Min Looks like were headed for a small cycle 10

11 PVRC Webinar 18 & 21July 2012 K9LA First Sunspot of Cycle 24 11

12 PVRC Webinar 18 & 21July 2012 K9LA Current Cycle 24 Data Solar min around December 2008 Solar min around December 2008 Cycle 24 slow to start its ascent Cycle 24 slow to start its ascent Have we reached Cycle 24s peak or is this just a temporary lull? Have we reached Cycle 24s peak or is this just a temporary lull? 12

13 PVRC Webinar 18 & 21July 2012 K9LA In Terms of 10.7 cm Solar Flux 13 Similar trends

14 PVRC Webinar 18 & 21July 2012 K9LA Geomagnetic 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? 14

15 PVRC Webinar 18 & 21July 2012 K9LA Cycle 24 vs Cycle 23 For a short time Cycle 24 rate of ascent was comparable to Cycle 23 For a short time Cycle 24 rate of ascent was comparable to Cycle 23 But Cycle 24 was slower to start – tends to indicate lower cycle But Cycle 24 was slower to start – tends to indicate lower cycle 15

16 Current Predictions PVRC Webinar 18 & 21July 2012 K9LA International Space Environment ServiceMarshall Space Flight Center

17 A Very Early Prediction PVRC Webinar 18 & 21July 2012 K9LA If only it were true! 17

18 PVRC Webinar 18 & 21July 2012 K9LA Seasonal effects 18

19 PVRC Webinar 18 & 21July 2012 K9LA Seasonal Effects With the smoothed sunspot number hovering around 60 (smoothed 10.7 cm solar flux around 120) beginning in August 2011, seasonal effects become noticeable for 10m propagation With the smoothed sunspot number hovering around 60 (smoothed 10.7 cm solar flux around 120) beginning in August 2011, seasonal effects become noticeable for 10m propagation Lets look at the MUFs along two paths at a smoothed sunspot number of 60 Lets look at the MUFs along two paths at a smoothed sunspot number of 60 –W3 to EU, to JA, and to S. America –G to Eastern EU, to W4, and to JA 19

20 PVRC Webinar 18 & 21July 2012 K9LA W3 to EU October thru December good for 10-Meters October thru December good for 10-Meters Summer months worst Summer months worst 20

21 PVRC Webinar 18 & 21July 2012 K9LA W3 to JA October best for 10-Meters October best for 10-Meters Summer months worst Summer months worst 21

22 PVRC Webinar 18 & 21July 2012 K9LA W3 to S America September thru April good for 10-Meters September thru April good for 10-Meters –Thanks to the robust equatorial ionosphere Summer months worst Summer months worst 22

23 G to Eastern Europe October thru February best for 10-Meters October thru February best for 10-Meters Summer months worst Summer months worst PVRC Webinar 18 & 21July 2012 K9LA23

24 G to W4 October thru February good for 10-Meters October thru February good for 10-Meters Summer months worst Summer months worst PVRC Webinar 18 & 21July 2012 K9LA24

25 G to JA October best for 10-Meters October best for 10-Meters Summer months worst Summer months worst PVRC Webinar 18 & 21July 2012 K9LA25

26 PVRC Webinar 18 & 21July 2012 K9LA Last Fall vs This Spring Decrease in monthly mean solar activity resulted in leveling off of the smoothed value Decrease in monthly mean solar activity resulted in leveling off of the smoothed value As we moved from Fall/Winter to the Spring, seasonal effects came into play As we moved from Fall/Winter to the Spring, seasonal effects came into play In general, 10-Meters for CQ WW and ARRL 10M good, ARRL DX and CQ WPX not so good In general, 10-Meters for CQ WW and ARRL 10M good, ARRL DX and CQ WPX not so good This Fall – 10-Meters should be good This Fall – 10-Meters should be good But we need a more active Sun to help with 10- Meter propagation next Spring! But we need a more active Sun to help with 10- Meter propagation next Spring! 26

27 PVRC Webinar 18 & 21July 2012 K9LA Four FAQs 27

28 PVRC Webinar 18 & 21July 2012 K9LA #1 - Two Peaks for Cycle 24? Cycle 19, 20, and 21 didnt show much of a second peak Cycle 19, 20, and 21 didnt show much of a second peak Cycle 22 and 23 did show a definite second peak Cycle 22 and 23 did show a definite second peak –Cycle 23s second peak made 6-Meter DXers very happy in the Winter of 2001 Cycle 24 could have a second peak 28

29 PVRC Webinar 18 & 21July 2012 K9LA #2 - 6-Meter F 2 ? Paths not involving the equatorial ionosphere are very unlikely with the current Cycle 24 prediction Paths not involving the equatorial ionosphere are very unlikely with the current Cycle 24 prediction TEP is still possible TEP is still possible If F 2 does happen away from the equator, it would be most likely during the Spring, Fall, and Winter of 2013 If F 2 does happen away from the equator, it would be most likely during the Spring, Fall, and Winter of 2013 Sporadic E should still be there Sporadic E should still be there –Late morning and early evening in the Summer –Early evening in December 29

30 Recent 6m Opening - W7 to EU Probably not F 2 – most likely Es PVRC Webinar 18 & 21July 2012 K9LA 29 June 2012 foF 2 ~ 4.7 MHz F 2 MUF ~ 17.4 MHz foEs > 9.5 MHz Es MUF > 50 MHz 30

31 PVRC Webinar 18 & 21July 2012 K9LA #3 - Disappearing Sunspots? W. Livingston and M. Penn measured the maximum strength of magnetic fields of sunspots W. Livingston and M. Penn measured the maximum strength of magnetic fields of sunspots Strength has been declining since 1992 Strength has been declining since 1992 Need about 1500 gauss for sunspots to be visible Need about 1500 gauss for sunspots to be visible Extrapolating their data says sunspots will disappear by 2016 Extrapolating their data says sunspots will disappear by 2016 extrapolation 31

32 2012 Update PVRC Webinar 18 & 21July 2012 K9LA 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 32 Slope the same as previous plot – vertical axis in this plot is expanded

33 Sunspot Number vs Solar Flux PVRC Webinar 18 & 21July 2012 K9LA33 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 Cycle 23/24 data Also impacts propagation predictions using smoothed sunspot number

34 PVRC Webinar 18 & 21July 2012 K9LA #4 - Another Maunder Minimum? Maunder Minimum - lack of sunspots from Maunder Minimum - lack of sunspots from The three cycles before Maunder Minimum showed a smooth decrease in group sunspot number The three cycles before Maunder Minimum showed a smooth decrease in group sunspot number Its generally agreed that the Sun is slowing down Its generally agreed that the Sun is slowing down Cycles 22, 23, and 24 exhibit a smooth decrease, too Cycles 22, 23, and 24 exhibit a smooth decrease, too What Cycle 24 does and duration of solar min between Cycle 24 and 25 may suggest where were headed What Cycle 24 does and duration of solar min between Cycle 24 and 25 may suggest where were headed It very well may be there will still be an ionosphere It very well may be there will still be an ionosphere 34

35 PVRC Webinar 18 & 21July 2012 K9LA Trees and HF propagation 35

36 Trees and HF All of my antennas look through trees on headings from Northwest thru South Is this a problem? PVRC Webinar 18 & 21July 2012 K9LA 36

37 Trees and HF – Two Issues Foliage (leaves) – –Use the work of Tamir and Krevsky PVRC Webinar 18 & 21July 2012 K9LA 37

38 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 PVRC Webinar 18 & 21July 2012 K9LA 38

39 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 PVRC Webinar 18 & 21July 2012 K9LA 39

40 PVRC Webinar 18 & 21July 2012 K9LA Best antenna height 40

41 Best Height for Antenna Elevation statistics in the ARRL Antenna Book CD from N6BVs work Example: Indianapolis to six areas of the world and to the US Indianapolis to the world on 10-Meters PVRC Webinar 18 & 21July 2012 K9LA 41

42 Antenna Patterns 5-element 10m monobander over average ground PVRC Webinar 18 & 21July 2012 K9LA 42

43 Elevation Statistics + Patterns Best compromise height is ~ 1.5 wavelengths (50 ft) – –Agrees with W2PVs analysis in his book Yagi Antenna Design Need to stack antennas to cover all the angles PVRC Webinar 18 & 21July 2012 K9LA 43

44 PVRC Webinar 18 & 21July 2012 K9LA Summary Cycle 24 has leveled off Cycle 24 has leveled off –Is this temporary or are we at the peak? –Next several months will give us a clue Cycle 24 has a decent chance of two peaks Cycle 24 has a decent chance of two peaks –Would likely prolong propagation on the higher bands 6M F 2 propagation probably restricted to equatorial ionosphere 6M F 2 propagation probably restricted to equatorial ionosphere Sunspots may disappear, but EUV will likely still be there Sunspots may disappear, but EUV will likely still be there Too early to tell if were headed for another Maunder Minimum Too early to tell if were headed for another Maunder Minimum Even if we are, maybe it doesnt matter with respect to propagation Even if we are, maybe it doesnt matter with respect to propagation Expect good 10-Meter contest season for CQ WW and ARRL 10M Expect good 10-Meter contest season for CQ WW and ARRL 10M ARRL DX and CQ WPX next spring need more solar activity ARRL DX and CQ WPX next spring need more solar activity Dont worry too much about trees – especially in the winter Dont worry too much about trees – especially in the winter Try to put your antenna at the optimum height Try to put your antenna at the optimum height 44


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