Earth Proton Whistlers
Earth proton whistler

A proton whistler can only be detected in spacecraft measurements above Earth's ionosphere. The proton whistler will occur immediately after an upward-propagating whistler has been generated by a lightning discharge. It is distinct from the more common, lightning-generated whistler both in tone and spectral characteristics.

Unlike the lightning-generated whistler, the proton whistler consists of a long, slowly rising tone that begins at a low frequency and levels off in a monotone at a frequency just below the proton cyclotron frequency, a characteristic frequency of the ambient plasma. The tone will typically last several seconds.

This example is from the University of Iowa Injun 3 spacecraft.



Return to "Favorite Sounds" page

Return to "Space Audio" page


© The University of Iowa 2003-2013. All rights reserved. Audio clips freely licensed.
Contact information. Send questions or comments to the site custodian.
The Radio and Plasma Wave Group, Department of Physics & Astronomy, College of Liberal Arts & Sciences.
  Valid HTML 4.01!