Glossary
of terms.
Short definitions of the terms used in the book — drawn from science, photography and geography.
- Aurora
The coloured emissions observed at and around the poles when magnetic storms from the Sun reach the Earth.
- CME
Coronal mass ejection. A solar eruption, caused by tangled magnetic fields in the Sun's corona, that hurls a vast mass of plasma into space.
Related termsAuroraSolar fırtına
- Equinox
The moment the circle of illumination passes through the poles, when the Sun's rays strike the Equator perpendicularly and day and night are equal.
- Fjord
A bay formed where the lower reaches of steep-sided, deep glacial valleys — carved by glaciers along the coasts of Norway, Scotland and North America — are drowned by the sea.
- Infinity focus
The point on a manual-focus lens at which the most distant objects appear as sharp as possible. Autofocus is useless when shooting the Northern Lights.
Related termsRAW
- JPEG
A compressed digital image encoding format standardised by the Joint Photographic Experts Group.
Related termsRAW
- Kp index
A general index used in aurora forecasting, graded from 0 to 9. The ‘K’ index measures variations in the Earth's magnetic field. 0–1 is calmest; 5 and above means a geomagnetic storm.
- RAW
The raw file format in which the image falling on a digital camera's sensor — the equivalent of film — is converted to numerical data and stored by the processor.
Related termsJPEG
- Solar maximum
The peak of the Sun's roughly 11-year activity cycle. Eruptions and CMEs grow more frequent in this phase — stronger auroras become possible.
Related termsCME
- Thermal
Thermal conductivity. The property describing a material's ability to conduct heat. A deciding factor when choosing clothing for northern trips.