Glossary

Climate variability refers to fluctuations in the mean status and other statistical parameters concerning the climate (e.g. standard deviations, occurrence of extreme events, etc.) at all spatial and temporal scales above individual weather events. Climate parameters like temperature, wind speed and direction are neither spatially nor temporally constant. There are two types of climate variability: external and internal. External variability is caused e.g. by changes in solar radiation, changes in Earth’s parameters – like the angle of its axis – or the composition of the atmosphere due to e.g. volcanic eruptions, but also by human influences. Internal variability is chiefly chaotic and caused e.g. by the interplay of the atmosphere, ocean, sea ice and land surface.