The NERC MST Radar Facility at Aberystwyth

Sky-Camera Event-Log

The sky-camera event-log records the start and stop date-times of interesting phenomena seen in the 1-minute interval images. It currently covers the period 25th April 2007 - 3rd August 2008. We are grateful to Joseph Prentice, Emily Mackintosh, Daniel Khosla, Kathryn Stone, Kieran Cook, Natasha Bierrum, and Amelia Gilio, who contributed to the log whilst undertaking work experience placements at the Rutherford Appleton Laboratory.

Click here to download a copy of the sky-camera event log (103 kbyte) in plain text formate.

Examples of phenomena identified in the log:
Daybreak i.e. when it has become light enough for the images to be of use

Sunset i.e. when the Sun disappears beyond the horizon

Nightfall i.e. when it has become too dark for the images to be of use

Mountain waves i.e. cloud features which remain quasi-stationary relative to the landscape. These include the classic burger-shaped lenticular clouds, which are generated by air flow over an isolated hill. However, they are more often hot-dog-shaped clouds, which are generated by air flow over a ridge. This category probably also includes fair-weather cumulus clouds which are preferentially formed in particular locations.

Kelvin-Helmholtz Instabilities (KHIs) i.e. clouds which are characterised by a number of parallel bands. They can be similar in appearance to some mountain-wave clouds, but they have shorter horizontal wavelengths - typically just a few km. KHI patterns can often be seen in mountain wave clouds.

Active cumulus i.e. clouds which show considerable changes in vertical extent/structure from one image/minute to the next.

Dying cumulus i.e. active cumulus which is evaporating.

Cirrus i.e. high, thin cloud.

Mist i.e. ground level cloud.

Rain i.e. rain is falling

Rainbow i.e. a rainbow is visible

Contrails i.e. long, thin trails formed behind aircraft. These act as tracers of the wind.

Counterflow i.e. the clouds/contrails are moving in different (nominally counter) directions at different heights.

Moon i.e. the Moon is seen in the image. The camera auto-adjusts to the light level and so the Moon becomes more blurred after nightfall.

Planet i.e. Venus or Saturn is seen in the images. These are not very large but can be seen to follow a well-defined path from one image to the next.

Insect i.e. an insect is sitting directly in front of the camera. These are, in fact, typically spiders, which tend to move in spiral patterns around their webs.

Crepuscular rays i.e. radial bands of light/shadow radiating from the Sun.

Aesthetic i.e. something working looking at simply because it looks good.