The Radio Plasma Imager (RPI) passive mode spectrograms taken during the 2003 Halloween storm were sonified by mapping the RPI radio frequency range of 3 kHz to 550 kHz to the audible frequency range of 100 Hz to 7000 Hz, using "The vOICe" tool by Peter B. L. Meijer, www.seeingwithsound.com
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1. Example-1: (November 5, 2003 09:20-20:25 UT)
a fairly uneventful 11 hour pass of the IMAGE spacecraft through the Earth's magnetosphere compressed into 6 second presentation. .

• The changing-frequency tone corresponds to the thermal noise of the local plasma near its natural frequency at the spacecraft location that is detected by the RPI antennas.
• A faint high-pitch, "metallic" sound at the end of this magnetospheric pass corresponds to a weak type III solar radio burst usually associated with an elevated explosive activity on the Sun such as the ejection of energetic particles from the Sun's corona that typically accompanies the solar flares.

2. Example-2: (October 23-24, 2003 23:00-10:14)
a very quiet 11 hour RPI pass through the magnetosphere . A faint solar radio burst is heard at the end of the pass.
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3. Example-3: (October 27, 2003 12:00-23:04 UT)
RPI detects two solar radio bursts during its pass, audible as a high-pitch metallic sound. Both solar events that correspond to these two detected bursts were not ranked as remarkable as they did not exceed M5 X-Ray classification.
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4. Example-4: (November 4-5, 2003 19:07-06:16 UT)
captures the audio signature of a spectacular solar activity event on November 4, 2003. This mega-flare saturated NOAA GOES X-ray detectors and left the scientists guessing its classification, currently estimated at X28. This is the second time GOES detectors are saturated by solar activity. Highly sensitive receivers of the RPI can be saturated by much weaker events than this X28 flare.
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5. Example-5: (October 28 10:00 UT - October 31 07:00 UT)

[video with filled gaps]
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[video with original data gaps]

40 seconds of this track tell the story of the 2003 Halloween storm as observed by the RPI.

• It starts with a magnificent solar radio burst associated with an X17 flare. This flare is rated #4 on record since 1976.

• 19 hours after the X17 flare event, the energy from the Sun enters the Earth’s magnetosphere, causing a category G5 magnetic storm that lasts for 22 hours. The onset of the storm is audible on this audio track as the low and mid-range "rumble" starting 12 seconds into the track. This rumbling sound corresponds to a spectacular auroral kilometric radiation (AKR) and whistler-wave VLF activity in the magnetosphere.

• In the middle of the first magnetic storm, another X10 solar flare occurs, clearly audible at 19th second of the track.

• 20 hours after the second X10 solar flare event, another magnetic storm commences, noticeably weaker (category K8) and shorter (13 hours). The second storm can be heard closer to the end of the audio sequence starting at its 31st second.

• The data sequence has five gaps because of another experiment running during the orbit perigees. A signature restoration technique was used to create a version of the audio track with the filled gaps.



6. Example-6: (November 4, 2003 19:07-November 5, 2003 20:30 UT) Remarkably, the greatest solar flare on record, X28 on November 4, 2003, did not cause any noticeable storm activity on the Earth. The type III solar radio burst accompanying X28 flare has been detected by RPI (Example 4 above). However, when the particles from the flare reached the outer boundary of the Earth's magnetosphere, orientation of the interplanetary magnetic field (IMF) that solar wind drags away from the Sun did not match the magnetic field of the Earth, and no energy from the solar wind could enter the magnetosphere.
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