A new method for finding the height of the aurora

A new computerised method has been developed for quickly and automatically calculating the peak emission height of the aurora from a pair of camera images with overlapping fields of view.

When studying the aurora, estimates of its height are often needed in order to calculate other parameters, such as the widths of auroral structures or their speeds, which can then be used to calculate properties of the ionospheric plasma such as electric field strenghts or energy input in the auroral arc.

However, usually the height of the aurora is not measured, and so an assumption must be made. Typically these assumptions are based on research conducted many decades ago which is known to be inaccurate by modern standards. As the aurora is not opaque, traditional triangulation methods are difficult to apply accurately to the aurora. We have developed a new computerised method for quickly and automatically calculating the peak emission height of the aurora from a pair of camera images with overlapping fields of view.

FMI has operated all-sky cameras in Lapland for many decades. A very large statistical study (hundreds of thousands of measurements) of the height of the aurora using our new method and FMI's camera images will greatly improve estimates of the height when it cannot be measured directly, and will improve our understanding of how solar and magnetic processes affect the upper atmosphere in the Arctic.

Additional information:

Daniel Whiter, Arctic Research, tel. 029 539 2083, daniel.whiter@fmi.fi

Whiter, D.K., Gustavsson, B., Partamies, N., Sangalli, L., A new automatic method for estimating the peak auroral emission height from all-sky camera images. Geosci. Instrum. Method. Data Syst., 2, 131-144, doi: 10.5194/gi-2-131-2013,2013.