Monitoring Solar flares gby Radio Astronomy

Presented at the RASC Sunshine Coast CentrePresented at the RASC Sunshine Coast Centre, February 8th, 2013, 7:30 pm

Mike Bradley, RASC Sunshine Coast Centre

Solar flaresSolar flaresSolar flaresSolar flares

Solar flares occur when Solar flares occur when sunspots with very sunspots with very complex magnetic fields complex magnetic fields become unstable andbecome unstable andbecome unstable and become unstable and start to untangle start to untangle themselves. This themselves. This process releases veryprocess releases very Unstable sunspot groupUnstable sunspot groupprocess releases very process releases very large quantities of large quantities of energy . energy .

Unstable sunspot groupUnstable sunspot group

►►The XThe X--ray and UV energy released by these solar ray and UV energy released by these solar flares makes its way to Earth and interacts withflares makes its way to Earth and interacts withflares makes its way to Earth and interacts with flares makes its way to Earth and interacts with the upper atmosphere to create a SID.the upper atmosphere to create a SID.

IonosphericIonospheric LayersLayersIonosphericIonospheric LayersLayers

IonosphericIonospheric LayersLayersIonosphericIonospheric LayersLayers

►► •Topside•TopsideppFrom F2 layer to 500/1000km transition O+ less than From F2 layer to 500/1000km transition O+ less than

H+ & He+H+ & He+►► •F Layer•F Layer

Above 150km, reflecting F2 layer, ions NO+ to O+Above 150km, reflecting F2 layer, ions NO+ to O+►► E LayerE Layer►► •E Layer•E Layer

95 95 –– 150km, ions are mainly O++, also thick E2, thin 150km, ions are mainly O++, also thick E2, thin sporadic Esporadic Epp

►► •D Layer•D Layer75 75 –– 95km, weak 95km, weak ionisationionisation, absorbs HF, absorbs HF

Understanding the Understanding the ionosphericionosphericresponseresponse►► When the XWhen the X--ray and UV energy reaches the upper levels of ray and UV energy reaches the upper levels of y gy ppy gy pp

our atmosphere it rapidly increases the our atmosphere it rapidly increases the ionisationionisation levels of levels of the ionosphere levels that are responsible for refracting the ionosphere levels that are responsible for refracting terrestrial radio signalsterrestrial radio signalsterrestrial radio signals.terrestrial radio signals.

►► Terrestrial radio signals at very low frequencies (below Terrestrial radio signals at very low frequencies (below 30kH ) t id d b t th th30kH ) t id d b t th th30kHz) propagate as guided waves between the earths 30kHz) propagate as guided waves between the earths surface and the “D” layer. They can also penetrate surface and the “D” layer. They can also penetrate seawater to about 10m.seawater to about 10m.

►► During a solar flare the During a solar flare the ionisationionisation of the layer increases of the layer increases dramatically and its height rapidly reduces. After the flare, dramatically and its height rapidly reduces. After the flare, y g p y ,y g p y ,through recombination, its through recombination, its ionisationionisation gradually returns to gradually returns to normal and the layer gradually rises to its original level.normal and the layer gradually rises to its original level.

SuddenSudden IonosphericIonospheric Disturbance (SID)Disturbance (SID)Sudden Sudden IonosphericIonospheric Disturbance (SID)Disturbance (SID)

►►AA suddensudden ionosphericionospheric disturbancedisturbance is anis an►►A A sudden sudden ionosphericionospheric disturbancedisturbance is an is an abnormally high ionization/plasma density in the D abnormally high ionization/plasma density in the D region of the ionosphere caused by a solar flare. region of the ionosphere caused by a solar flare.

►►The SID results in a sudden increase in radioThe SID results in a sudden increase in radio--wave wave absorption that is most severe in the upper absorption that is most severe in the upper medium frequency (MF) and lower high frequency medium frequency (MF) and lower high frequency ( ) d l f( ) d l f(HF) ranges, and as a result often interrupts or (HF) ranges, and as a result often interrupts or interferes with telecommunications systems.interferes with telecommunications systems. **

* Federal Standard 1037C, * Federal Standard 1037C, Glossary of Telecommunications TermsGlossary of Telecommunications Terms

Quiet SunQuiet SunQuiet SunQuiet Sun

Very Low Frequency (VLF) radio signals (3...30kHz) are Very Low Frequency (VLF) radio signals (3...30kHz) are guided between the conducting ground and the Dguided between the conducting ground and the D--layer. layer. Th DTh D l i i f th i h th t il i i f th i h th t i i i di i dThe DThe D--layer is a region of the ionosphere that is layer is a region of the ionosphere that is ionisedioniseddirectly by solar radiation. It is present only during the day, directly by solar radiation. It is present only during the day, and responds quickly to changes in solar radiation.and responds quickly to changes in solar radiation.

Night timeNight timeNight timeNight time

At night, solar radiation cannot At night, solar radiation cannot ioniseionise the Dthe D--layer. Very layer. Very Low Frequency radio signals cannot propagate efficiently. Low Frequency radio signals cannot propagate efficiently. The EThe E--layer is responsible for reflecting higher frequency layer is responsible for reflecting higher frequency ee aye s espo s b e o e ect g g e eque cyaye s espo s b e o e ect g g e eque cyradio signals, which often rise in strength at night.radio signals, which often rise in strength at night.

Active sunActive sunActive sunActive sun

Solar flares produce UV and XSolar flares produce UV and X--rays, increasing the rays, increasing the ionisationionisation (electron density) of the D(electron density) of the D--layer. The Sudden layer. The Sudden IonosphericIonospheric Disturbances (SIDs) alter VLF propagationDisturbances (SIDs) alter VLF propagationIonosphericIonospheric Disturbances (SIDs) alter VLF propagation, Disturbances (SIDs) alter VLF propagation, producing rapid and distinctive changes in received signal producing rapid and distinctive changes in received signal strength.strength.

Very Low Frequency (VLF) radioVery Low Frequency (VLF) radioVery Low Frequency (VLF) radioVery Low Frequency (VLF) radio

►►The VLF signals we are interested are theThe VLF signals we are interested are the►►The VLF signals we are interested are the The VLF signals we are interested are the submarine signals used by all countries with submarine signals used by all countries with naval submarines Typically 3naval submarines Typically 3--30 kHz30 kHznaval submarines. Typically 3naval submarines. Typically 3 30 kHz.30 kHz.

►►VLF wavelength penetrate a short distance VLF wavelength penetrate a short distance into seawater so subs don’t need to surfaceinto seawater so subs don’t need to surfaceinto seawater so subs don t need to surface into seawater so subs don t need to surface to communicate.to communicate.M it i th i l i l l th d dM it i th i l i l l th d d►►Monitoring these signals is legal, the coded Monitoring these signals is legal, the coded information content is of no interest, it’s information content is of no interest, it’s

l th i l t th itl th i l t th itonly the signal strength we monitor. only the signal strength we monitor.

Jim Creek, WA, US Navy transmitterJim Creek, WA, US Navy transmitterJim Creek, WA, US Navy transmitterJim Creek, WA, US Navy transmitter

About 24.8 kHzAbout 24.8 kHz

••Amplitude (PeakAmplitude (Peak--toto--Peak)Peak)

••1 Cycle = 1 Cycle = 12 km12 km

••RadioRadio

•• Distance traveled over time Distance traveled over time

o Signal o Signal

••How to make this Computation?How to make this Computation?••Speed of light:Speed of light: c = c = 300,000 km/Sec300,000 km/SecFF ff 24 800 C l /S24 800 C l /S••Frequency:Frequency: f f = 24,800 Cycles/Sec= 24,800 Cycles/Sec

••Wave Length:Wave Length: λλ = c / f = c / f km km / Cycle/ Cycle

The VLF signals I monitorThe VLF signals I monitorThe VLF signals I monitorThe VLF signals I monitor

La Moure NDLa Moure NDJim Creek WAJim Creek WA

La Moure NDLa Moure ND

Jim Creek is so close (150 km) that the ground wave signal Jim Creek is so close (150 km) that the ground wave signal dominates. La Moure gives better results (2500 km)dominates. La Moure gives better results (2500 km)

Detecting the signalDetecting the signalDetecting the signalDetecting the signal

►►The frequencies we are trying to monitor are similarThe frequencies we are trying to monitor are similar►►The frequencies we are trying to monitor are similar The frequencies we are trying to monitor are similar wavelengths to audio waves, but they are wavelengths to audio waves, but they are electricalelectrical, , not not soundsound pressurepressure waves.waves.

►►A microphone converts sound pressure variations intoA microphone converts sound pressure variations intoelectrical signals. An antenna converts electrical electrical signals. An antenna converts electrical waves into electrical signals.waves into electrical signals.

►► Simply connecting an antenna to the soundcard of a Simply connecting an antenna to the soundcard of a h lh l dd ddcomputer is the simplest way to computer is the simplest way to digitisedigitise and capture and capture

the signals we want.the signals we want.E l d d f b t!E l d d f b t!►► Even on cloudy days, from your basement!Even on cloudy days, from your basement!

Detecting the signalDetecting the signalDetecting the signalDetecting the signal

►►Alternatively a dedicated very low frequencyAlternatively a dedicated very low frequency►►Alternatively a dedicated very low frequency Alternatively a dedicated very low frequency (VLF) receiver can be used(VLF) receiver can be used

►►Several designs most not too difficult to buildSeveral designs most not too difficult to build►►Several designs, most not too difficult to buildSeveral designs, most not too difficult to build►►Amateur and Educational commercial units Amateur and Educational commercial units

il blil blavailableavailable

Continuously recording the signalContinuously recording the signalContinuously recording the signalContinuously recording the signal

►►Save the output from the PC soundcard as aSave the output from the PC soundcard as a►►Save the output from the PC soundcard as a Save the output from the PC soundcard as a file, analogue or digital.file, analogue or digital.

orororor►►Capture the average signal strength as a Capture the average signal strength as a

lt h t d llt h t d lvoltage on a chart recorder or an analogue voltage on a chart recorder or an analogue to digital converterto digital converter

►►Observe and Observe and analyseanalyseyy

Flat file structureFlat file structureFlat file structureFlat file structure

UTC 24800 25000 2520000.00.01 ‐95.52 ‐112.59 ‐112.2600.00.21 ‐95.66 ‐112.79 ‐112.2800 00 41 95 7 112 83 112 3300.00.41 ‐95.7 ‐112.83 ‐112.3300.01.01 ‐95.76 ‐113.03 ‐112.1900.01.21 ‐95.9 ‐113.07 ‐112.2800.01.21 95.9 113.07 112.2800.01.41 ‐95.97 ‐113.25 ‐112.37

23.59.01 ‐97.75 ‐113.73 ‐114.1423 59 21 97 75 113 91 114 2923.59.21 ‐97.75 ‐113.91 ‐114.2923.59.41 ‐97.64 ‐114.15 ‐114.95

SoftwareSoftwareSoftwareSoftware

►► Spectrum Lab is a full featured audio analysisSpectrum Lab is a full featured audio analysis►► Spectrum Lab is a full featured audio analysis Spectrum Lab is a full featured audio analysis program, it performs frequency analysis and program, it performs frequency analysis and spectrum sampling, ideal for SID. It is also free.spectrum sampling, ideal for SID. It is also free.

►►The frequency analysis is done using the Fast The frequency analysis is done using the Fast Fourier Transform rather than discrete filters andFourier Transform rather than discrete filters andFourier Transform rather than discrete filters and Fourier Transform rather than discrete filters and therefore the therefore the NyquistNyquist sampling limit applysampling limit apply

►►This means the PC soundcard must be able to This means the PC soundcard must be able to sample at a minimum of twice the highest frequency sample at a minimum of twice the highest frequency b i b d i 25 2kHb i b d i 25 2kH 50 4 kH50 4 kH 96kH96kHbeing observed i.e. 25.2kHz being observed i.e. 25.2kHz --> 50.4 kHz > 50.4 kHz --> 96kHz> 96kHz

Spectrum LabSpectrum Lab ––Audio spectrum screenAudio spectrum screenSpectrum Lab Spectrum Lab Audio spectrum screenAudio spectrum screen

Audio spectrumAudio spectrum

Waterfall chartWaterfall chart

Spectrum LabSpectrum Lab –– FFT detailFFT detailSpectrum Lab Spectrum Lab FFT detailFFT detail

Jim Creek WA 24.8 kHzJim Creek WA 24.8 kHz La Moure ND 25.5 kHzLa Moure ND 25.5 kHz

Unknown, Russian Federation 25.0 kHzUnknown, Russian Federation 25.0 kHz

Spectrum Lab can be configured to save the values ofSpectrum Lab can be configured to save the values ofSpectrum Lab can be configured to save the values of Spectrum Lab can be configured to save the values of these peaks to a simple text file or to simply draw a chart.these peaks to a simple text file or to simply draw a chart.

Normal 24 Hr. Day (No flares)Normal 24 Hr. Day (No flares)3

Normal 24 Hr. Day (No flares)Normal 24 Hr. Day (No flares)

2

2.5

••LocalLocal NoonNoon

1

1.5

0

0.5

03 31 59 27 56 24 52 20 48 16 44 12 40 08 36 04 32 00 28 56 24 53 21 49 17 45 13 41 09 37 05 33 01 29 57 25 53 21 50 18 46

07:

00:

07:

35:

08:

10:

08:

46:

09:

21:

09:

57:

10:

32:

11:

08:

11:

43:

12:

19:

12:

54:

13:

30:

14:

05:

14:

41:

15:

16:

15:

52:

16:

27:

17:

03:

17:

38:

18:

13:

18:

49:

19:

24:

20:

00:

20:

35:

21:

11:

21:

46:

22:

22:

22:

57:

23:

33:

00:

08:

00:

44:

01:

19:

01:

55:

02:

30:

03:

05:

03:

41:

04:

16:

04:

52:

05:

27:

06:

03:

06:

38:

••NighttimeNighttime••Time in UTTime in UT

••SunriseSunrise

••SunsetSunset••NighttimeNighttime

••NighttimeNighttime

••DaytimeDaytime

Detecting Solar Flares Detecting Solar Flares –– SID(s)SID(s)gg ( )( )

5SID Events!SID Events!

4

4.5

••SID Events!SID Events!

3

3.5

2

2.5

03 26 48 11 34 56 19 42 05 27 50 13 35 58 21 44 06 29 52 14 37 00 23 45 08 31 53 16 39 01 24 47 10 32 55 18 40 03 26 49 11 34 57 19 42 05

Local Nighttime DaytimeSunrise Local Nighttime

07:

00:0

07:

31:2

08:

02:4

08:

34:1

09:

05:3

09:

36:5

10:

08:1

10:

39:4

11:

11:0

11:

42:2

12:

13:5

12:

45:1

13:

16:3

13:

47:5

14:

19:2

14:

50:4

15:

22:0

15:

53:2

16:

24:5

16:

56:1

17:

27:3

17:

59:0

18:

30:2

19:

01:4

19:

33:0

20:

04:3

20:

35:5

21:

07:1

21:

38:3

22:

10:0

22:

41:2

23:

12:4

23:

44:1

00:

15:3

00:

46:5

01:

18:1

01:

49:4

02:

21:0

02:

52:2

03:

23:4

03:

55:1

04:

26:3

04:

57:5

05:

29:1

06:

00:4

06:

32:0

However, not all SID events are explainable. Research is However, not all SID events are explainable. Research is needed to help answer needed to help answer ““What are these events?What are these events?””

Connecting SID to GOES XConnecting SID to GOES X--ray ray satellite datasatellite datasatellite datasatellite data

5

C5 9C5 9

4

4.5 ••C4.5C4.5••C5.9C5.9

••C3.8C3.8

••M1.3M1.3

3

3.5

2

2.5

03 26 48 11 34 56 19 42 05 27 50 13 35 58 21 44 06 29 52 14 37 00 23 45 08 31 53 16 39 01 24 47 10 32 55 18 40 03 26 49 11 34 57 19 42 05

Local Nighttime DaytimeSunrise Local Nighttime

07:

00:0

07:

31:2

08:

02:4

08:

34:1

09:

05:3

09:

36:5

10:

08:1

10:

39:4

11:

11:0

11:

42:2

12:

13:5

12:

45:1

13:

16:3

13:

47:5

14:

19:2

14:

50:4

15:

22:0

15:

53:2

16:

24:5

16:

56:1

17:

27:3

17:

59:0

18:

30:2

19:

01:4

19:

33:0

20:

04:3

20:

35:5

21:

07:1

21:

38:3

22:

10:0

22:

41:2

23:

12:4

23:

44:1

00:

15:3

00:

46:5

01:

18:1

01:

49:4

02:

21:0

02:

52:2

03:

23:4

03:

55:1

04:

26:3

04:

57:5

05:

29:1

06:

00:4

06:

32:0

Flare ClassificationsFlare ClassificationsFlare ClassificationsFlare Classifications

Class Energy 6

X 10-4..10-3W/m2

M 10-5..10-4W/m23

4

5

C 10-6..10-5W/m2

B 10-7..10-6W/m20

1

2

3

/

A 10-8..10-7W/m2

0

A B C M X

Logarithmic scale, each class can be further divided by 10, Logarithmic scale, each class can be further divided by 10, ieie C 5.6 or M1.5C 5.6 or M1.5

Typical quiet sun produces energy in the A or B class, Most flares fall into Typical quiet sun produces energy in the A or B class, Most flares fall into the B or C class Very energetic flares are M or X classthe B or C class Very energetic flares are M or X classthe B or C class. Very energetic flares are M or X class.the B or C class. Very energetic flares are M or X class.

Extremely energetic flares can exceed X9.9, Extremely energetic flares can exceed X9.9, ieie X20!!!X20!!!

Solar activity varies from day to daySolar activity varies from day to daySolar activity varies from day to daySolar activity varies from day to day

Animation courtesy Moore Observatory, KentuckyAnimation courtesy Moore Observatory, Kentucky

Nov 13Nov 13thth from Roberts Creekfrom Roberts CreekNov 13Nov 13 from Roberts Creekfrom Roberts Creek

-90

-100

-95

-115

-110

-105

-120

00.0

0.01

00.2

8.21

00.5

6.41

01.2

5.01

01.5

3.21

02.2

1.41

02.5

0.01

03.1

8.21

03.4

6.41

04.1

5.01

04.4

3.21

05.1

1.41

05.4

0.01

06.0

8.20

06.3

6.40

07.0

5.00

07.3

3.20

08.0

1.40

08.3

0.00

08.5

8.20

09.2

6.40

09.5

5.00

10.2

3.20

10.5

1.40

11.2

0.00

11.4

8.20

12.1

6.40

12.4

5.00

13.1

3.20

13.4

1.40

14.1

0.00

14.3

8.20

15.0

6.40

15.3

5.00

16.0

3.20

16.3

1.40

17.0

0.00

17.2

8.20

17.5

6.41

18.2

5.01

18.5

3.21

19.2

1.41

19.5

0.01

20.1

8.21

20.4

6.41

21.1

5.01

21.4

3.21

22.1

1.41

22.4

0.01

23.0

8.21

23.3

6.41

••UTC UTC

Nov 13Nov 13thth from Roberts Creekfrom Roberts CreekNov 13Nov 13 from Roberts Creekfrom Roberts Creek

-105

NML VLF (N.Dakota)X Class flare 6.1e-3, Event 2410

-106

dB

-108

-107

2.21

4.41

7.01

9.21

1.41

4.01

6.21

8.41

1.01

3.21

5.41

8.01

0.21

2.41

5.01

7.21

9.41

2.01

4.21

6.41

9.01

1.21

3.41

6.01

8.21

0.41

3.01

5.21

7.41

0.01

2.21

4.41

7.01

9.21

1.41

4.01

6.21

8.41

1.01

3.21

5.41

8.01

20.3

220

.34

20.3

720

.39

20.4

20.4

420

.46

20.4

820

.520

.53

20.5

520

.58

21.0

021

.02

21.0

521

.07

21.0

921

.12

21.1

421

.16

21.1

921

.221

.23

21.2

621

.28

21.3

021

.33

21.3

521

.37

21.4

021

.42

21.4

421

.47

21.4

921

.521

.54

21.5

621

.58

22.0

22.0

322

.05

22.0

8

UTC

Sunspot AR1613, Event 2410Sunspot AR1613, Event 2410Sunspot AR1613, Event 2410Sunspot AR1613, Event 2410

Solar image courtesy Solar image courtesy HeliumFusionHeliumFusion channel, YouTubechannel, YouTube

ConclusionsConclusionsConclusionsConclusions

►►Strictly speaking this is not aStrictly speaking this is not a radioradio►►Strictly speaking this is not a Strictly speaking this is not a radio radio telescopetelescope. We are not detecting radio waves . We are not detecting radio waves directly from spacedirectly from spacedirectly from space.directly from space.

►►Instead we are detecting the effect of solar Instead we are detecting the effect of solar activity indirectly so it is certainlyactivity indirectly so it is certainly radioradioactivity indirectly, so it is certainly activity indirectly, so it is certainly radio radio astronomyastronomy!!A i l l t i t ti j t fA i l l t i t ti j t f►►A simple, low cost, interesting project for a A simple, low cost, interesting project for a rainy afternoonrainy afternoon

A proper Radio Telescope!A proper Radio Telescope!A proper Radio Telescope!A proper Radio Telescope!

Dominion Radio Astrophysical Observatory (DRAO)Dominion Radio Astrophysical Observatory (DRAO)Dominion Radio Astrophysical Observatory (DRAO) Dominion Radio Astrophysical Observatory (DRAO) at White at White Lake in the Okanagan. The Lake in the Okanagan. The area is federally area is federally protected from radio protected from radio interference.interference.

Thank you for your y yattention!

Questions?Questions?

Tuning the Antenna (not essential)Tuning the Antenna (not essential)Tuning the Antenna (not essential)Tuning the Antenna (not essential)

25.2kHz25.2kHz