kamloops arc nov 2015 k9la the sun, the ionosphere and hf propagation carl luetzelschwab k9la...

Kamloops ARC Nov 2015 K9LA Kamloops ARC Nov 2015 K9LA

The Sun, the Ionosphere The Sun, the Ionosphere and HF Propagationand HF Propagation

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

http://k9la.ushttp://k9la.us


Who Is K9LA?Who Is K9LA? Received Novice license (WN9AVT) in Oct 1961Received Novice license (WN9AVT) in Oct 1961 Selected K9LA in 1977Selected K9LA in 1977 Interests includeInterests include

• PropagationPropagation• DXingDXing• ContestingContesting• Playing with antennasPlaying with antennas• Vintage equipmentVintage equipment

DXpeditions include YK9A (Syria, 2001), OJ0 DXpeditions include YK9A (Syria, 2001), OJ0 (Market Reef, 2002) and ZF (Cayman Islands, (Market Reef, 2002) and ZF (Cayman Islands, many times)many times)

Wife is Vicky AE9YL/ZF2YLWife is Vicky AE9YL/ZF2YL

Viking Ranger II HQ-170A


Some of My Favorite Movie StarsSome of My Favorite Movie Stars


But This Is My But This Is My FavoriteFavorite Star Star


Some Facts About the SunSome Facts About the Sun Radiates energy at many Radiates energy at many

wavelengthswavelengths Highest intensity is at Highest intensity is at

visible light wavelengths visible light wavelengths (400-700 nm)(400-700 nm)

Wavelengths that ionize Wavelengths that ionize the atmosphere (.1-100 the atmosphere (.1-100 nm) are much shorter nm) are much shorter than visible lightthan visible light

Visible light has nothing Visible light has nothing to do with the ionization to do with the ionization process – not enough process – not enough energyenergy• Same for 10.7 cm solar fluxSame for 10.7 cm solar flux

0 250 500 750 1000 1250 1500 1750 2000 2250 2500wavelength in nm

Solar Radiation Spectrum

inte

nsi

ty

Ionizing wavelengths.1 to 100 nm

10.7 cm

The shorter the wavelength, the more the energy (Planck’s Law)


Early Ionospheric StudiesEarly Ionospheric Studies 1901 – Marconi hears Poldhu1901 – Marconi hears Poldhu 1902 – Kennelly (US) & Heaviside (UK) independently 1902 – Kennelly (US) & Heaviside (UK) independently

suggest that the Earth’s upper atmosphere consists of an suggest that the Earth’s upper atmosphere consists of an electrically conducting region (the Kennelly-Heaviside layer)electrically conducting region (the Kennelly-Heaviside layer)

1925 – Appleton finds conclusive evidence of a conducting 1925 – Appleton finds conclusive evidence of a conducting region by measuring arrival angles of nearby transmitterregion by measuring arrival angles of nearby transmitter

1925 – Breit and Tuve confirm existence of reflecting region 1925 – Breit and Tuve confirm existence of reflecting region with the first ionosonde with the first ionosonde ((sswept-frequency upward-looking radar)wept-frequency upward-looking radar)

1926 - Watson-Watt coins the term “ionosphere”1926 - Watson-Watt coins the term “ionosphere” 1927 – Sharp decrease in critical frequency (measured by 1927 – Sharp decrease in critical frequency (measured by

an ionosonde) seen during solar eclipse – deduce that solar an ionosonde) seen during solar eclipse – deduce that solar radiation forms the ionosphereradiation forms the ionosphere

1928 – Pettit ties sunspots to solar radiation – the more 1928 – Pettit ties sunspots to solar radiation – the more sunspots, the more radiationsunspots, the more radiation


SunspotsSunspots

Sunspots are the result of magnetic fields in the Sunspots are the result of magnetic fields in the Sun that erupt through the surface, forming a Sun that erupt through the surface, forming a huge magnetic loophuge magnetic loop

The solar surface in this area cools significantly, The solar surface in this area cools significantly, causing this area to be darkercausing this area to be darker

The area around the sunspot emits radiation at The area around the sunspot emits radiation at wavelengths that ionize the atmospherewavelengths that ionize the atmosphere• Sunspots (and 10.7 cm solar flux) are a proxy for the Sunspots (and 10.7 cm solar flux) are a proxy for the

true ionizing radiationtrue ionizing radiation


Solar CycleSolar Cycle Average length (A to C) is Average length (A to C) is

11 years11 years• Average rise time (A to B) is 4 Average rise time (A to B) is 4

yearsyears• Average fall time (B to C) is 7 Average fall time (B to C) is 7

yearsyears Solar cycle may have two Solar cycle may have two

peakspeaks We measure solar cycles We measure solar cycles

using a smoothed solar using a smoothed solar index to “smooth out” the index to “smooth out” the spikiness of daily and spikiness of daily and monthly mean valuesmonthly mean values

The maximum value variesThe maximum value varies

Smoothed solar index could be smoothed sunspot number or smoothed 10.7 cm solar flux


Two PeaksTwo Peaks

Cycles 21, 22, 23 and now 24 had a second peakCycles 21, 22, 23 and now 24 had a second peak What does this mean?What does this mean?

• Good question!Good question!


Recorded HistoryRecorded History

Three periods of large cycles, two periods of small cyclesThree periods of large cycles, two periods of small cycles Looks like we’re headed for some small solar cyclesLooks like we’re headed for some small solar cycles

• Corroborating evidence is cycle max vs duration of previous minCorroborating evidence is cycle max vs duration of previous min

Dalton minimum

Cycle 1 began in 1755


Duration of Cycle MinimumsDuration of Cycle Minimums

On the left is the duration of solar minimumsOn the left is the duration of solar minimums• Out-of-phase with plot on previous slideOut-of-phase with plot on previous slide

On the right is a scatter diagram of months at solar On the right is a scatter diagram of months at solar minimum vs magnitude of next peakminimum vs magnitude of next peak

The longer the duration of solar minimum, the smaller the The longer the duration of solar minimum, the smaller the next cyclenext cycle


Early HistoryEarly History

Carbon-14 (and Beryllium-10) are proxies for solar activityCarbon-14 (and Beryllium-10) are proxies for solar activity• Tied to galactic cosmic raysTied to galactic cosmic rays

Are we headed for another Maunder Minimum?Are we headed for another Maunder Minimum?• Some say yes, most say no – duration of minimum between Cycle 24 Some say yes, most say no – duration of minimum between Cycle 24

and 25 should give us a hint of where we’re headedand 25 should give us a hint of where we’re headed

Cycles 5,6 ,7

the most well known minimum (~ 1645-1715)

Positive 14C is solar minimumNegative 14C is solar maximum


Solar Cycle 24 StatusSolar Cycle 24 Status

Blue vertical bars are monthly meansBlue vertical bars are monthly means Red line is smoothed valueRed line is smoothed value First peak in early 2012 – second peak in mid 2014First peak in early 2012 – second peak in mid 2014


The AtmosphereThe Atmosphere Atmosphere is most Atmosphere is most

often defined by often defined by temperature (yellow temperature (yellow line)line)

Terrestrial weather is Terrestrial weather is in the troposphere in the troposphere and lower and lower stratospherestratosphere

Ionosphere starts in Ionosphere starts in the mesospherethe mesosphere


The IonosphereThe Ionosphere Remember that ionizing Remember that ionizing

radiation is at wavelengths radiation is at wavelengths between .1 and 100 nmbetween .1 and 100 nm

The shorter the wavelength, The shorter the wavelength, the more the energythe more the energy• The more the energy, the lower The more the energy, the lower

it gets into the atmosphereit gets into the atmosphere F region above ~ 160 kmF region above ~ 160 km

• 10-100 nm wavelengths (EUV)10-100 nm wavelengths (EUV) E region from ~ 90-160 kmE region from ~ 90-160 km

• 1-10 nm wavelengths (soft x-rays)1-10 nm wavelengths (soft x-rays) D region from ~ 70-90 kmD region from ~ 70-90 km

• .1-1 nm wavelengths (hard x-rays).1-1 nm wavelengths (hard x-rays)R is the smoothed sunspot numberR=0 is solar minimumR=200 is solar maximum


Critical Frequency and MUFCritical Frequency and MUF

Ionosondes measure the critical frequencies of Ionosondes measure the critical frequencies of the ionospherethe ionosphere• Critical frequency of a region is the frequency at which Critical frequency of a region is the frequency at which

the RF pulse does not return to Earth (it goes through the RF pulse does not return to Earth (it goes through the region)the region)

• Ionosondes report critical frequencies for the E, F1 and Ionosondes report critical frequencies for the E, F1 and F2 regions (and sporadic E when present)F2 regions (and sporadic E when present)

Using spherical geometry, we can estimate the Using spherical geometry, we can estimate the maximum frequency that will propagate over a maximum frequency that will propagate over a given path at a given timegiven path at a given time


Critical Frequency ExampleCritical Frequency Example As the elevation angle is As the elevation angle is

lowered from 90lowered from 90oo, higher , higher frequencies are refracted frequencies are refracted back to Earthback to Earth

The highest frequency that The highest frequency that is refracted back to Earth is refracted back to Earth when launched at a low when launched at a low elevation angle is about 3 elevation angle is about 3 times the critical frequencytimes the critical frequency

This is the maximum This is the maximum useable frequency (MUF)useable frequency (MUF)

In this example, the MUF In this example, the MUF would be about 24 MHzwould be about 24 MHz

F region

3 MHz 8 MHz

ionosonde varies its frequency


Variability of the IonosphereVariability of the Ionosphere The ionosphere varies significantlyThe ionosphere varies significantly

• Over a solar cycle - most ionization at solar maximumOver a solar cycle - most ionization at solar maximum• Monthly – Fall months best in northern hemisphereMonthly – Fall months best in northern hemisphere• Throughout the day – max around noon, min before dawnThroughout the day – max around noon, min before dawn

The ionosphere is affected by disturbances to propagationThe ionosphere is affected by disturbances to propagation Our understanding of the ionosphere is statistical in nature Our understanding of the ionosphere is statistical in nature

over a month’s time frameover a month’s time frame• Thus our propagation predictions are statistical in nature over Thus our propagation predictions are statistical in nature over

a month’s time framea month’s time frame• We do not have a daily model of the ionosphereWe do not have a daily model of the ionosphere


The BandsThe Bands Our bands fall into three categoriesOur bands fall into three categories

• 160m, 80m, 40m: these bands are very 160m, 80m, 40m: these bands are very dependent on ionospheric absorptiondependent on ionospheric absorption

Best during the night and best at solar minimumBest during the night and best at solar minimum

• 15m, 12m, 10m: these bands are very 15m, 12m, 10m: these bands are very dependent on the MUFdependent on the MUF

Best during the day and best at solar maximumBest during the day and best at solar maximum

• 30m, 20m, 17m: these are transition bands30m, 20m, 17m: these are transition bands Not entirely dependent on absorptionNot entirely dependent on absorption Not entirely dependent on MUFNot entirely dependent on MUF Hold up well throughout a solar cycleHold up well throughout a solar cycle


Space WeatherSpace Weather

Current weather parameters and Current weather parameters and assessment of band conditionsassessment of band conditions

www.qrz.com


What We DesireWhat We Desire Solar activitySolar activity

• In general we desire a high sunspot number (0-In general we desire a high sunspot number (0-200) and a high 10.7 cm solar flux (65-300)200) and a high 10.7 cm solar flux (65-300)

• Openings vs 10.7 cm solar fluxOpenings vs 10.7 cm solar flux 10m: long-term solar flux > 10010m: long-term solar flux > 100 12m: long-term solar flux > 7512m: long-term solar flux > 75 15m: long-term solar flux > 5015m: long-term solar flux > 50

Geomagnetic field activityGeomagnetic field activity• In general we desire A < 7 and K < 2In general we desire A < 7 and K < 2

A and K are measures of the deviation of the Earth’s A and K are measures of the deviation of the Earth’s magnetic field from quiet conditionsmagnetic field from quiet conditions

A is a daily index, K is a 3-hour indexA is a daily index, K is a 3-hour index


What Bands Are Open?What Bands Are Open?

Since we don’t have a daily model of the Since we don’t have a daily model of the ionosphere, knowing the 10.7 cm solar flux does ionosphere, knowing the 10.7 cm solar flux does not pin down the MUF for a given path at a given not pin down the MUF for a given path at a given timetime

We can use propagation predictions to give a We can use propagation predictions to give a statistical view of what the best band would be statistical view of what the best band would be for the desired pathfor the desired path• W6ELProp is a user-friendly propagation prediction W6ELProp is a user-friendly propagation prediction

program that is a free downloadprogram that is a free download• Visit the Tutorials link at http://k9la.us for info about Visit the Tutorials link at http://k9la.us for info about

W6ELProp (how to download it, set it up and interpret W6ELProp (how to download it, set it up and interpret the results)the results)


Listen Real-Time!Listen Real-Time!

The IARU/NCDXF beacon project has a The IARU/NCDXF beacon project has a beacon on 20m, 17m, 15m, 12m and 10m beacon on 20m, 17m, 15m, 12m and 10m in 18 countries worldwidein 18 countries worldwide

Each beacon transmits for 10 seconds – so Each beacon transmits for 10 seconds – so in 3 minutes you can assess worldwide in 3 minutes you can assess worldwide openings on a bandopenings on a band

http://www.ncdxf.org/pages/beacons.html http://www.ncdxf.org/pages/beacons.html for detailsfor details


Use Real-Time SpotsUse Real-Time Spots Select LF-HF Select LF-HF

or VHF & upor VHF & up Select bandSelect band Select Select

geographical geographical areaarea

Spots are Spots are shown for the shown for the designated designated time periodtime period

from www.dxmaps.com


Modes of PropagationModes of Propagation

Most of our HF QSOs are made via the true Most of our HF QSOs are made via the true great circle short pathgreat circle short path

Other HF propagation modes existOther HF propagation modes exist• Long pathLong path• Skewed pathSkewed path• Scatter path (implies loss = weak signal)Scatter path (implies loss = weak signal)

Path could be via F region, E region, EPath could be via F region, E region, Ess region, auroral ionization, equatorial region, auroral ionization, equatorial ionization (TEP), etcionization (TEP), etc


NoiseNoise Usually a problem Usually a problem

on the lower on the lower bands (160m and bands (160m and 80m)80m)

Two categoriesTwo categories• Man-madeMan-made• AtmosphericAtmospheric

Mitigation for Mitigation for • Man-made noise – check your house and neighbor’s Man-made noise – check your house and neighbor’s

house, work with power companyhouse, work with power company• Atmospheric noise – use low-noise receive antennasAtmospheric noise – use low-noise receive antennas


Disturbances to PropagationDisturbances to Propagation


Disturbances – The Big PictureDisturbances – The Big Picture

Worst is geomagnetic storm – several days to a weekWorst is geomagnetic storm – several days to a week• Caused by CME or coronal holeCaused by CME or coronal hole

Solar radiation storm – couple daysSolar radiation storm – couple days Radio blackout – couple hoursRadio blackout – couple hours

both caused by big solar flare


Solar FlaresSolar Flares

Emit lots of radiation at x-ray wavelengths (very Emit lots of radiation at x-ray wavelengths (very short)short)

Biggest is X-ClassBiggest is X-Class Next down is M-ClassNext down is M-Class Next down is C-ClassNext down is C-Class Least is B-ClassLeast is B-Class Visit http://www.swpc.noaa.gov/noaa-scales-Visit http://www.swpc.noaa.gov/noaa-scales-

explanation for details of disturbances to explanation for details of disturbances to propagationpropagation


SummarySummary

The Sun radiates at many wavelengthsThe Sun radiates at many wavelengths• .1-100 nm is important for the ionosphere.1-100 nm is important for the ionosphere

Looks like we’re headed for some smaller Looks like we’re headed for some smaller solar cyclessolar cycles• How small is the questionHow small is the question

Ionosphere varies significantly day-to-dayIonosphere varies significantly day-to-day• Forces us to use a statistical modelForces us to use a statistical model

Several ways to assess band conditionsSeveral ways to assess band conditions• Use them to help your operating habitsUse them to help your operating habits

kamloops arc nov 2015 k9la the sun, the ionosphere and hf propagation carl luetzelschwab k9la...

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