Stormy Space Weather spawns aurora and gorgeous natural VLF radio sounds.
Aurora photo taken by S. P. McGreevy in northern Manitoba, Canada on 23 August 1996.
This website has been reconstructed to emphasize the soundscapes of Natural VLF Radio and less on the technical details of the phenomena, although I will keep many of the more technical documents on this site that appeared in the former versions of these web pages.
A: Natural ELF/VLF Radio - also called "Natural Radio" - are audio-frequency radio signals of Earth in the approximately 200 Hz to beyond 10,000 Hz (10 kHz) spectrum which are not man-made but occur naturally in nature. Most of the best phenomena are heard between 400 Hz and 5 kHz.
Science and SoundScapes: Interest in naturally-occurring ELF/VLF radio phenomena such as "whistlers" and "chorus" has enjoyed a rapid resurgence during the 1990's on the part of academic research via orbiting space-probes and ground-based monitoring efforts, and also notably amongst amateur hobbyists world-wide thanks to easy availability of sensitive receiving equipment. As Solar-Cycle 23 begins, we're seeing increased solar-activity spawn greater amounts VLF phenomena here on Earth, as it is activity on the Sun and its Solar Wind that help create the great variety of VLF phenomena that we can monitor - whether for research and experimentation, or simply for the enjoyment of listening to yet another realm of nature's beauty!
Most importantly, a great many people who are not really "radio nuts" or "techies" but who love nature and listening to interesting sounds have listened to Natural Radio either live or recorded and have called it the "music of Earth itself." To listen and enjoy Natural Radio, the audio-frequency radio waves must be converted directly to sound frequencies so we can listen to them with our ears. This is what my receiving eqipment does, and the enjoyment of collecting a large recorded library of these phenomena (beginning in June 1989) is my foremost interest.
Lightning storms, Earth's magnetic-field (the Magnetosphere), and the Aurora Borealis and Australis (Northern & Southern Lights) all produce an amazing variety of electromagnetic "sounds," such as sferics (lightning-stroke static), tweeks, Whistlers of countless variety, the incredible "Chorus" chirping, barking and squawking radio "sounds" produced by the the Sun's solar-wind hitting Earth's magnetic-field; various kinds of "Hiss"; bizzarre "wavering-tone" emissions, and other endless variety of fascinating radio sounds to listen to.
The WR-4b receiver's VLF vertical whip antenna is attached to van on its rear door. This is the VLF receiving system and expedition "accomodation" I have used for the past 7 years.
Natural VLF radio signals tell a great deal of what is happening with Earth's "near-space weather," that is, what is going on between the Sun and Earth. Invisible weather to our eyes but just as wild and stormy at times as the weather "down here."
Auroral curtains photographed at 0500 UTC on 23 August 1996 in Manitoba, Canada during my SOLAR-MINIMUM VLF RECORDING EXPEDITION. Photo by Stephen P. McGreevy
Many listeners to natural VLF radio note how the majority of these recordings of Earth's beautiful Natural VLF Radio sounds closely resemble biological/vocal sounds made by birds, frogs, whales, seals, etc. (or sci-fi sound effects). As we begin a new Solar-Cycle (#23) and see increasing numbers of sunspots and associated magnetic-storms and disturbances here on Earth, we're already seeing an upsurge in naturally-occurring VLF phenomena. Between now and the sunspot peak in the years 1999 - 2001, we're entering a fabulous time once again to listen to radio signals below 10 kHz.
In addition to the audio files page on this site, there is another webpage of
audio files I have recorded residing on the University of Iowa Plasma Wave
Group server.
Travels to Great VLF
Listening Spots. A travelogue, with photographs, of beautiful places I (and
others) have traveled to listen to Natural Radio away from electrical
interference. Enjoy!
VLF LISTENER'S HANDBOOK
(Text-only version) I have combined the text portions only (no images or
hyperlinks) of the THE VLF STORY (see link below too for entire version); The
WR-3/3E LISTENING GUIDE; plus a sheet describing the various SOUNDS OF VLF
PHENOMENA. Save to your hard-drive and read/print off-line with your web
browser. Chock full of about 50(+) pages of information all about Natural
ELF/VLF Radio (145K of HTML text as of October 1997)
Download and listen to Natural Radio recordings in .WAV file format I have
placed at the University of Iowa Plasma Wave Physics web site. McGreevy Ground-based VLF
Recordings.
Are you a do-it-yourself electronics-project builder? Check out the McGreevy
BBB-4 "Bare Bones Basic"
Receiver page.
Natural Radio
Audio-Files Page:
Audio-files of great 1993 - 1999 Natural ELF/VLF Radio recordings in .WAV
format are on this site on the page link right above. On this page, NEW 16
bit/22050 kHz sampled STEREO files have been added. Most others are mono/8-bit
11 kHz, 50K - 500K. All of the audio files available for downloading tell (more
than a million words would) all about the incredable variety of natural radio
signals that can be monitored in the audio-frequency radio spectrum. Hearing is
believing!
OTHER NATURAL VLF RADIO INFORMATION PAGES AND DOCUMENTS:
The VLF Story: A
story of my beginnings in VLF listening back in 1989 and subsequent travels to
obtain my recordings. Includes a brief history of professional and amateur VLF
research and easy-to-understand theory about the causes of these phenomena.
Description of Natural
Radio "Sounds" These descriptions of VLF phenomena help you interpret what
you're hearing - whether with a VLF receiver or what is presented in the .WAV
audio-file recordings on these web sites
1996 SOLAR MINUMUM
Expedition to Manitoba, Canada. This report also includes detailed
descriptions and PHOTOGRAPHS of the nightly displays of the Northern Lights
(Aurora) I viewed while there from 22 August to 05 September 1996 and what
natural ELF-VLF radio events correlated to them each day.
MORE VLF RECORDINGS/WR-3E VLF RECEIVER INFORMATION:
WR-3/WR-3E VLF Receiver
Listening Guide: A good source to learn more about natural radio, ** even
though this receiver is no longer for sale from this site. **
Still much more about
Natural VLF Radio...:
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