Climate pattern

A climate pattern is any recurring event that produces climatic change. Climate patterns can be long-term events, like ice ages, or shorter-term events, like monsoons.

A climate pattern may be regular, like the diurnal cycle or the seasonal cycle, or irregular, like El Niño. The regular cycles are generally well understood and may be removed by filtering in some discussions: for example, graphs of trends of temperature change will have the seasonal cycle removed.

Modes of variability

A mode of variability is a climate pattern with identifiable characteristics, specific regional effects, and often oscillatory behavior. Many modes of variablity are used by climatologists as indices to represent the general climatic state of a region affected by a given climate pattern.

Measured via an empirical orthogonal function analysis, the mode of variability with the greatest effect on climates worldwide is the seasonal cycle, followed by El Niño-Southern Oscillation, followed by thermohaline circulation.

Other well-known modes of variability include:

• The Antarctic oscillation
• The Arctic oscillation
• The Atlantic multidecadal oscillation
• The Indian Ocean Dipole
• The Madden–Julian oscillation
• The North Atlantic oscillation
• The Pacific decadal oscillation
• The Pacific-North American teleconnection pattern
• The Quasi-biennial oscillation

See also

• Climate change

Further reading

Natural climate variability at the National Institute of Geophysics and Vulcanology (Bologna, Italy)