All-Sky Cameras If you were lying on your back looking up at the sky, with your feet pointing North and your head pointing South, what would you see? The image on the left shows you the answer - nearly the entire sky, with North near the bottom, South near the top, East on the right, and West on the left. All-Sky cameras face directly upwards and use a special "fish-eye" lense to capture images of the aurora from horizon-to-horizon.
All-Sky cameras also use image intensifiers to amplfiy low levels of auroral light that might go undetected using the naked eye. The All-Sky image above was recorded at the Poker Flat Research Range and shows a bright auroral arc on the Northern horizon, stretching along the East-West direction.
DOWNLOAD an MPEG movie of an auroral substorm (431 KB)
Magnetic Field Data
As shown in the aurora section, auroral light is caused by the flow of large currents in the ionosphere and in space. Whenever a current is present, a magnetic field is generated, thus strong changes in auroral currents produce large deviations in the magnetic fields sensed on Earth. The plot above shows changes in the Earth's magnetic field in the direction pointing towards North during auroral activity. The sharp dip in the magnetic field roughly 37 minutes into the data plot is a result of an auroral arc (current) moving over the magnetometer sensor at Fort Yukon, Alaska. Scientists use this sharp dip in field strength to track the progress of aurora and predict its future position and strength.