This collection of naturally-occurring ELF/VLF audio recordings (now in MP3 file format) and the spectrograms below were made by Stephen P. McGreevy between 1996 to 2011. This page (and linked pages) includes mono audio files recorded from tapes made during VLF recording sessions in Alberta and Manitoba, Canada (1993, 1995, 1996), STEREO recordings made in Waterton Peace Park, Alberta Canada, June 1998, and two additional Canadian Expeditions in 2000 and 2001. Plus, there are recent recordings made from the California desert near and in Death Valley National Park and the Eastern Sierra and Joshua Tree Nat. Park. in the Southeastern California desert, and abroad within Greater London, and the Donegal Coast of Ireland...
Some of the below (a portion of older files dated pre-2001) MP3 format audio files (128, 96 or 64 kbps) were converted from original source .WAV files of various sample and bit rates and may vary a bit in quality.
Newer MP3-file additons to this website (archives and newer recordings from 2002 to 2010) have been made directly from the original cassette, mini-disc or SD-chip recorder (a Zoom H2), and are at 128 kbs rate for the best quality for the file sizes, although it is a tad less than the original field-recordings (as some quality-loss is present in compressed-audio-file formats like MP3). Sometimes, MP3 audio compression at low data rates tends to make the impulse-noise sounds of lightning static sound a bit odd, especially if encoded into the MP3 format at less than 128 kbs rate - otherwise the VLF phenomena is reproduced faithfully).
The several receivers I used to make most of these audio-file recordings were a McGreevy WR-4b unit with a couple of 2 to 3-meter-tall whip verticals attached to my camper/van you see in photos below; hand-held WR-3 receivers of various ages; two cross-azimuth verticaly-hung delta-loops made of several turns of wire - used mainly in Canada for the STEREO recording expeditions (in the summers of 1998, 2000, and 2001) employing a large-loop antenna receiving system design by Stephen Ratzlaff alongside a version of his design adapted for my McGreevy WR-4b receiver. Quite a few recordings are made on hikes using a few versions of the hand-held McGreevy WR-3 receiver.
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) - you have to hear them to believe the variety and beauty...they are the sounds of "Space Weather!"
2013 VLF recordings now are on the "Auroral Chorus IV" page at Internet Archives. Please click this link to go there.
17-19 March 2013 Whistlers AND 13-15 May 2013 Whistler Barrage:
Saturday, 14 July 2012 "Whistler Shower" - Inyo County, Calif.
Many moderate-strength near-pure-tone 2-hop whistlers per-minute (occurring after very-strong lightning sferics from storms over the Intermountain Western North America especially up in Washington and northern IDaho as well as southern BC and AB). These whistlers were recorded near Keeler on 14 July 2012 at approx. 1140 UT (0440 PDT) via The VLF-to-FM Relay. Click lightning-location photo and this link to hear the audio-file (about 1 minute duration).
Longer versions of this 14 July 2012 whistler-event have been uploaded to my "Auroral Chorus IV" page on Internet Archive (click here to go to that page of a large compendium of 2011-2012 VLF recordings).
2013 VLF recordings now are on the "Auroral Chorus IV" page at Internet Archives. Please click this link to go there.
The first night after adding this new solar-panel, the Inyo VLF to FM 87.9 MHz Relay produced lovely whistlers (many pure-tone) the entire night of 18-19 Feb. 2012 (PST dates) - Recording of a whistler cluster - 19 Feb. 2012 - 0808z - near Keeler, Calif. (5 sec. file / 80 kb)
Several weak-to-moderate-strength semi-pure-tone whistlers per-minute (occurring after strong lightning sferics from storms over Nevada, Utah and Arizona) were recorded near Keeler on Tuesday, 04 October 2011 at approx. 0845 UT (0145 PDT) via a hand-held WR-3e Receiver. Click spectrogram and this link to hear the audio-file (7.5 sec. duration).
A few strong pure-tone whistlers per-minute with echoes were recorded near Keeler on Friday, 30 September 2011 at approx. 1220 UT (0520 PDT) via the VLF to FM Relay depicted below. Click spectrogram and this link to hear the audio-file (about 25 sec. duration).
On 08 September 2011 at approx. 2300 UT, the SOHO and STEREO spacecraft detected a huge Mercury-directed CME occurred, resulting in a magnetic-storm on Earth. This is the Goddard Space Weather Lab animated-gif model of this CME - it is quite amazing to look at(!):
Click here to view this animation. I will be out recording natural VLF Radio early the morning of 10 Sept. 2011 in Inyo County, CA, and will have the results below...stand-by...
(Well, it didn't produce much, being not-directed at Earth but towards Venus.
But, another CME is approaching Earth and to arrive about 26 Sept. 2011 at 1400 UT, so maybe I'll have another chance at hearing good VLF signals... (NOPE, nothing again!)
Another gigantic CME on 27 Jan. 2012 (NASA-GSFC animation - I didn't hear any VLF sounds at 37 latitude north, but this one did largely miss Earth. I find these animations quite amazing and they best show the rotation-spiral outward of the solar-wind and the various solar-wind streams that affect radio-propagation at any given time.
Click the spectrogram above/or this sentence for the .mp3 audio file
Hopefully, this section now to more-rapidly fill with new audio files beginning mid-May or June 2010 (when I fix the lack of solar-panel input problem - see below). The receiver is a prototype "WR-5a" version - see bottom of: http://www.auroralchorus.com or CLICK HERE for WR-5a schematic. - S.P. McGreevy - Photos by Mike Mideke, WB6EER.
It is early the morning of 05 October 2010: Wonderful, pure-tone (loud) whistlers about 1 per minute between 0330 - 0445 PDT (1030 - 1145 UT) via Keeler, CA VLf to FM relay (recorded! - a file upload here when I can get to it and can process the file/compile it) - SpM. (more news below relay info.)
(The most recent-uploaded VLF-relay reception reports are further below)
It is now Sunday, 17 April 2010 at 1600 UT, and there are several (short) single-hop whistlers per-minute coming from source lightning in the southern hemisphere. They peaked in numbers and strength for about 15 minutes, then rapidly declined to maybe 10% of peak levels by 1625 UT. VLF Propagation changes quickly!
These whistler events seem to come and go -- similar to how sporadic-E skip openings come and go -- the whistler channel/ducts seem to form, merge, and evaporate, thus the rate of whistlers varies wildly hour to hour, with some hours and periods of tens of minutes devoid of any whistlers, then, anytime between sunset and early daylight, there have been events of diffuse to near-pure-tone whistlers since 10 April when the relay went in.
(It seems I did not put enough solar-panel wattage on the VLF-relay battery, as of 25 April 2010, it sent only a few hours of VLF audio mid-day, then failed when it grew to be late-afternoon.
On 11 May 2010 at 0800 local time, I installed another 5 watt solar-panel on the VLF-relay 2.2 miles / 3.5 km. This afternoon (11 May 2010 @ 2000 UT), there are occasional strong pure-tone whistlers occurring MID-DAY! The VLF to FM relay is(?) back in service and has a good signal again after 3 weeks down-time, although it seems by late-efternoon, some ominous (but apparantly harmless) popping/glitching sounds from high winds (big gales!)S.P. McGreevy, 11 May 2010.
Yes! The VLF to FM Relay is working PERFECTLY PAST 4 days - the extra solar panel I hiked in with (5 watts from CDT-Solar) has charged up the battery and it is onge again transmitting 24hours on 87.9 MHz to our hi-fi's in Keeler.
REPORT: few to no whistlers and heavy p.m. thunderstorm sferics (static) each day, tweeks at night lovely as always, though. I can hear ALPHA (Russia) well - this is at 1415 UT - 15 May 2010. S.P. McGreevy, 15 May 2010. -
Weak Dawn Chorus recorded via the VLF to FM relay, Sat. 29 May 2010 at 1406 UT - Keeler, California (Owens Valley). (1.5 MB MP3)
REPORT: lovely whistlers the night/morning of Sunday 06 June 2010, and light thunderstorm sferics (static) that day, great tweeks that night as heard via the Relay - wonderful VLF conditions and very aesthetic! 06 June 2010. I went camping with Mike Mideke, WB6EER the following night into the White Mountains, NV. and slept out under the very bright stars.
There have been a number of good whistler events during the summer of 2010 - especially around dawn.
On Wednesday, 08 September 2010, there are about 1 to 2 weak to strong single-hop (short) whistlers/minute occurring between sunrise to approx. 1645 UT. via the Relay.
The Relay received a great pure-tone whistler event the morning of 05 October 2010 - 1300 - 1500 UT (963 KB / 1:22 file). During the winter, it failed to operate all night. A new battery (18 aH) and ASC Charge-controller was installed 12 Jan. 2011 (see pic. below). Between 14 - 17 January 2011, numerous "fast-whistlers" have been heard via the Relay. S. P. McGreevy, 17 January 2011
Fast "riccochet" type whistlers occurring at a few-per-minute rate at 1336 UT on 17 January 2011 via the VLF to FM Relay (1.2 MB / 128 kbps MP3)
On 23 March 2011, I heard several fast-whistlers (1-hop) with my WR-3 situated 35 km/22 miles from home, near Darwin, CA. On the morning of 24 March 2011, Mike and I hiked to the VLF Relay (VLF to FM) and installed a new 10-watt CDT-Solar brand panel. This has eliminated the lack of PV-charge to the 18 aH battery and has instantly resulted in 24 hours of full-strength/sensitivity relaying of VLF activity to our FM-receivers in nearby Keeler. On both nights of 24-25 and 25-26 March 2011, lovely whistlers poured-forth between sunset and approx. 0200 local time (PDT) before fading away - thus proving again that sunrise is not always the best time for whistler activity.
Newer 2011 recordings of mine are available on the "Auroral Chorus IV" page on Internet Archives at:
Click image to hear the two whistlers (.mp3)
Not far east of Boundary Peak, Nevada, at 8200 ft. elevation/2500 metres elevation. Photo by Dear (Peaceful/Zen) Friend, Mike, WB6EER. Deep VLF-quiet locale (3-aspects: - night-sky darkness, acousticlly-quiet, VLF-quiet - no-hum) - (no A.C. powerline-hum at all on high-sensitivity e-field WR-3 receiver) and also one of the darkest-sky locales in the western Great Basin region of North American Continent for dark-sky astronomy - I spent half of the night with my Celestron 50x7 Astronomical Binoculars gazing at Scorpius and Sagittarius and the centre of the Milky Way Galaxy, early Monday 07 June 2010, under gorgeous, mild-late-spring temps in the high-50s F (low) and about 80F for high. - N6NKS.
Fairly acoustically-quiet mountain-paradise locale - northern White Mountains experience only the gentle sounds of passenger airliners along the "Coaldale Air-Corridor" approach to S.F. Bay Area (monitor 132.05 MHz).
ZEN-Man WB6EER whom loves quiet-wilderness and QRPp operating/HF-beacons, as I also.
'Whizzer' type whistler (8 sec. / 116 kb) - maybe one occurrence every few minutes, occurred on the morning of wednesday 11 July 2007 at about 1245 ut / 0545 Pacific time - recorded hand-held with WR-3ga/WR-3GX receiver and Sony minidisc recorder.
whistorm_stereo_mideke_ca22aug90.mp3 (1826 kb / 160 kbps MP3 - 1:33) - recorded near San Simeon, CA at 1605 UTC, 22 Aug. 1990. STEREO using two different long-wires (> 1000 ft. long) and receivers. (INSPIRE RS-3 receivers)
whisstorm_mcg_nv_21aug90_v_vlf.mp3 (1238 kb / 160 kbps MP3 - 1:03) - a whistler storm with chorus and hiss recorded by S. McGreevy near Paradise Valley, (northern) Nevada (north of Winnemucca) 21 Aug. 1990, 1700 ut - the first day of two events 21-22 Aug. 1990. Recorded on McGreevy version of Mideke/INSPIRE RS-3 receiver (predated the McGreevy BBB-4 whip-antenna-receiver by a year or so) with 200 foot longwire.
whistlers_mideke_oct89.mp3 (3138 kb / 160 kbps MP3 - 2:54:) Spectacularly echoing whistlers recorded by Michael Mideke near San Simeon sometime in October 1989.
2) Two whistlers occurring within 1/4second, at about 1233 UT, 74 kb, 5 sec.
Exact receiving installation in/on van as the 06 June '05 recoridngs below.
My favorite summertime listening site west of Lone Pine against the Sierra Nevada mtns. - Picture shows the van antennas, the VLF copper-pipe vertical antenna being on the rear of the van on the right. I caught a few whistlers the morning of 06 June 2005.
2) whistler cluster at about 1430 UT, 94 kb, 4.5 sec.
Typical high summertime static levels.
2) Cluster of weak upward-rising tones (risers) and subtle high-latitude phenomena (at about 0200 ut, 11 Feb 05) 640 KB, 128 kbps, 40 sec.
The pervasive AC grid: Notice the faint AC powerline hum in the two audio file recordings above: the closest large AC powerlines are about 15 miles to the west in the Owens Valley, a small set runs along Calif. State Route 190 some ten miles to the south and southwest, and yet, AC hum is still audible - sometimes from two different grids with a very slight difference in a.c. mains frequencies (0.1 Hz for example)! There are few places within the California deserts as electrically remote and quiet as here - no artificial lights of any kind are visible in this location - perfect also for dark-sky astronomy and other radio reception experimentation and DXing. (approx. coords. 36.5N/117.6W)
2) Cluster of weak whistlers after lightning bolt cluster72 KB, 96 kbps
2) whistlers_mt_vision_prns_marin_012104_1145z.mp3 1182 KB, 128 kbps stream
3) whistlers_mt_vision_prns_marin_012104_1150z.mp3 680 KB, 128 kbps stream
The three MP3 files above are recent January coastal California whister recordings in MP3 file-format above, and were recorded (using a WR-3) during an actual video shoot at dawn and sunrise on the morning of wed. 21 January 2004 atop Mount Vision in the Pt. Reyes National Seashore. There are some bits of the video camera's electronic noise present in the background of portions of these recordings above, albeit quite faint overall.
1) whistlers_south_dv_02nov03_0950z_dvnp_inyo_ca.mp3 2848 KB, 128 kbs stream
Steve McGreevy in Darwin, Calif. on 23 Sept. 2003 with WR-3 Receiver recording the fast whistlers in above audio-file
London Battersea Park Whistlers recorded 10 May 1996 at 9:10 p.m. BST handheld with a WR-3 into my Marantz PMD-212 cassette recorder, somewhere in an open place away from trees north of the football (soccer) playing pitches near the western edge of the park. The varying levels of background hum are from the railway lines from Victoria Station that pass by the western edge of the park. 55 sec., 654 KB, 64 kbps MP3 file.
The audio files on this site are for the delight and fascination of everyone visiting this page. Use of them in presentations is encouraged. Thank you. NOTHING ON THIS SITE IS COPYRIGHTED - ALL PUBLIC-DOMAIN.Stephen P. McGreevy, Feb. 2012
Build the McGreevy BBB-4b Whistler Receiver