Recording Auroral Observations All Images © Richard Pearce 1998 New Book

The following information is intended to help the auroral observer to make useful records of displays. Observations of a display should be recorded every 15 minutes unless the display is inactive such as a distant, unchanging glow. In this case time intervals may be increased. Conversely some displays may so active that continuous recording will be necessary. A useful device here is a battery operated microcassette recorder

Links To Information Areas General Information   Auroral Observation Codes Auroral Brightness Scale Condition Changes In Brightness Form Colours Example Code

General Information 1 Name of the person making the observation 2 Date (In double date format. i.e. an observation made on the evening of 28 October before midnight should be recorded as 28/29 October to remove the possibility of any ambiguity) 3 Time in Universal Time (GMT) 4 Location (In terms of latitude and longitude) 5 The height and azimuth of the highest part of the base of the display 6 The height and azimuth of the highest part of the top of the display 7 The extreme azimuth ranges of the display (N=000°, E=090°, S=180°, W=270°) Auroral Observation Codes The following codes can be used to increase the amount of detail recorded about any auroral display. Auroral Brightness Scale   Care must be taken when recording the brightness of a display as there is the tendency to over estimate. i Weak, similar to the milky way ii Like moonlit cirrus clouds iii Quite strong aurora, comparable in brightness to moonlit cumulus clouds iv Stronger than iii, possibly even bright enough to cast shadows Condition Aurorae may be either quiet(q), with no movement, or active (a). Activity may take several forms; a1 Folding bands a2 Rapid change of shape in lower structure a3 Rapid horizontal movement of rays a4 Fading of forms, with rapid replacement by others   Changes In Brightness Changes in brightness are described by (p) followed by a subscript;   p1 Slow pulsing p2 Flaming; waves of light passing vertically through the display p3 Flickering; rapid, irregular variations p4 Streaming; irregular horizontal variations in homogeneous forms   Form Form describes the overall type of display and whether or not any kind of structure can be seen. G Glow with no other structure, often lying low above northern horizon A Arc structure, an arch of light spanning east-west across the sky. May be homogeneous (HA) or rayed (RA) B Folded band structure, often developing from arc. May be homogeneous (HB) or rayed (RB) R Rays may sometimes be seen in isolation or in bundles V A background veil of light P Patches or 'surfaces' of auroral light. May be homogeneous (HP) or rayed (RP) N Auroral light, not readily identifiable, seen perhaps through cloud   Colours Colours seen in an aurora are described by lowercase letters;   a Red in upper area of aurora only b Red in lower area of aurora only c Green, White or Yellow d Red e Red and Green together f Blue or Purple   Example Code R1Bp23c - Describes a green, white or yellow rayed band showing short, bright rays.