Whistlers

Many years ago (1970) I did my final year project at university on whistlers. These are VLF natural emissions. I very nearly did a PhD on whistlers.

My final year university project involved trips to north Wales to record whistlers. These were later analysed in the university labs on kit we designed and made.

See https://sites.google.com/site/g3xbmqrp3/vlf/whistlers

Whistlers at VLF

As an undergraduate (a long time ago!) I did a project on whistlers, which are natural VLF noises produced as a result of VLF emissions being dispersed along magnetic field lines. I nearly did a PhD studying these. There are lots of different natural sounds at VLF. Whistlers are just one type. Tweeks are far more common. I recall going out to quiet parts of Wales to make recordings, although tweeks could even be heard in the centre of Liverpool after the manmade noises subsided late at night.

See https://soundcloud.com/nasa/whistler-waves2 . Eerie noises and not manmade.

Robert Helliwell

The death of Emeritus Professor Robert Helliwell of Stamford University was announced today. Helliwell was the author of the book "Whistlers and Related Ionospheric Phenomena" back in 1965. This is a wonderful book on the subject of VLF atmospheric physics which is still available from Amazon.

Whistlers!

This evening the VLF natural noise receiver in Todmorden, UK is buzzing with whistlers in addition to the almost continuous stream of tweeks. Whistlers are audible frequency descending tones caused by the dispersion of a lightning triggered impulse as it travels along magnetic field lines. At the moment I'm hearing about one whistler every 2 minutes.

Radio Nature

A very happy Christmas everyone. One of my presents was the book called "Radio Nature" by Renato Romero which is a very good introduction to the weird and wonderful world of ELF/VLF natural emissions such as whistlers and tweeks. The book, available from the RSGB on-line bookstore, is an excellent read.

See also his excellent webpages at http://www.vlf.it/ .