ARLA/CLUSTER: Descarga solar escuta-se em 20,9 e 22,6 MHz

[João Costa > CT1FBF]

Anvil Screamer: corona discharge pulses - spectrograph

Thomas Ashcraft has released a recording made at his shortwave radio
observatory of a corona discharge on 20.9 and 22.6 MHz

The Vimeo description reads:

This afternoon a developing electrical storm snuck up on my radio
observatory without much preceding lightning or sonic thunder to warn
me. I was inside, deep in my head working on a project when I started
to hear the howl of an "anvil screamer" through two of my radios at
22.6 MHz and 20.9 MHz.

I have heard this phenomenon before in conjunction with an approaching
storm before so I sprang into action and disengaged my antennas
expecting a lightning strike to happen at any moment. It is possible I
was directly under a highly charged anvil part of a lightning cloud.

This so-called "anvil screamer" was caused by a corona discharge on my
antennas as small discharges occurred off of pointy objects ( grasses
and cactus spines ) in the vicinity of the antennas due to a charge
differential between the ground and the air. I did not get it together
in time to look outside but my antennas might have been glowing violet
blue in this moment with St. Elmo's Fire.

I was able to capture a one minute forty second radio recording which
builds in intensity and frequency and then stops abruptly as I got my
system unplugged and disconnected.

Luckily, no close lightning bolt struck, as I thought I was about to
"meet my maker" so to speak. It was a close call in any case.

Listen to the recording at
http://vimeo.com/93097274