Nighttime Data Research Projects
Obviously, solar activity will affect the ionosphere only during
the daytime. But many phenomena such as lighting storms, whistlers, and gamma
ray bursts have a dramatic effect on the nighttime ionosphere, when effects
from the Sun can no longer drown them out.
Stanford's STAR Laboratory - VLF Group investigates the Earth's electrical
environment, lightning discharges, radiation belts, and the ionosphere. The
AWESOME instrument data is broad-band and much more sensitive than the SID instrument's
and thus more useful for nighttime ionospheric research.
To get a feel for nighttime ionospheric VLF remote sensing, you might want
to look at the HAIL Project,
which investigates changes in the lower ionosphere produced by thunderstorms
and associated lightning activity. The primary tool used by HAIL is a world-wide
network of AWESOME-like sensors.
[we need much more info here on what students can do with
Picking up Gamma Ray Bursts
On 27 December, 2004, Stanford ionospheric researchers detected the largest
gamma-ray burst ever recorded. It came from a magnetar -- a neutron star with
an enormous magnetic field -- some 50,000 light years away. Its powerful rays
penetrated deep into the Earth's ionosphere where effects were captured by
VLF receivers similar to the AWESOMEs.
Gamma-ray bursts are short-lived explosions of gamma-ray photons, the
most energetic form of light. Some of them are associated with a supernovae,
marking the deaths of especially massive stars. Lasting anywhere from a few
milliseconds to several minutes, gamma-ray bursts shine hundreds of times
brighter than a typical supernova and about a million trillion times as bright
as the Sun.
Enormous gamma-ray flares such as the December one affect
our lower ionosphere to such a massive degree that, by watching and measuring
its response to and recovery from the flare, we learn about the dynamics of
these upper atmospheric regions. The full story about this event can be found
Big gamma-ray flare from star disturbs Earth's ionosphere
Gamma ray bursts are rare and spontaneous events. We wouldn't
expect students to use their AWESOMEs solely to wait for these to occur. However,
if your students pick up a significant and unexplained change to the ionosphere,
they may have detected a gamma ray burst. See Gamma-ray
Burst Real-time Sky Map to check lists of current and known gamma ray