A climate oscillation is any oscillation

Oscillation

Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...

 within global or regional climate

Climate

Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

. These fluctuations in atmospheric temperature

Temperature

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...

, sea surface temperature

Sea surface temperature

Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...

, precipitation

Precipitation

Precipitation may refer to:* Precipitation , rain, sleet, hail, snow and other forms of water falling from the sky* Precipitation , the condensation of a solid from a solution during a chemical reaction...

 or other parameters can be quasi-periodic, often occurring on inter-annual, multi-annual, decadal, multidecadal, century-wide, millennial or longer timescale

Dynamical time scale

Dynamical time scale has two distinct meanings and usages, both related to astronomy:#In one use, which occurs in stellar physics, the dynamical time scale is alternatively known as the freefall time scale, and is in general, the length of time over which changes in one part of a body can be...

s. A prominent example is the El Niño-Southern Oscillation

El Niño-Southern Oscillation

El Niño/La Niña-Southern Oscillation, or ENSO, is a quasiperiodic climate pattern that occurs across the tropical Pacific Ocean roughly every five years...

, involving sea surface temperatures along a strech of the equatorial Central and East Pacific Ocean

Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 and the western coast of tropical South America, but which affects climate worldwide.

Origins and causes

There are close correlations between Earth's climate oscillations and astronomical factors (barycenter changes, solar variation

Solar variation

Solar variation is the change in the amount of radiation emitted by the Sun and in its spectral distribution over years to millennia. These variations have periodic components, the main one being the approximately 11-year solar cycle . The changes also have aperiodic fluctuations...

, cosmic ray

Cosmic ray

Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...

 flux, Milankovic cycles), and modes of heat distribution

Thermodynamics

Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...

 between the ocean-atmosphere climate system. In some cases, current, historical and paleoclimatological natural oscillations may be masked by significant volcanic eruptions, impact event

Impact event

An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...

s, irregularities in climate proxy data, positive feedback

Positive feedback

Positive feedback is a process in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation. That is, A produces more of B which in turn produces more of A. In contrast, a system that responds to a perturbation in a way that reduces its effect is...

 processes or anthropogenic

Anthropogenic

Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...

 emissions of substances such as greenhouse gas

Greenhouse gas

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

es.

Effects

Extreme phases of short-term climate oscillations such as ENSO can result in characteristic patterns of flood

Flood

A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

s and drought

Drought

A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...

s, monsoon

Monsoon

Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...

al disruption and extreme temperatures in the form of heat wave

Heat wave

A heat wave is a prolonged period of excessively hot weather, which may be accompanied by high humidity. There is no universal definition of a heat wave; the term is relative to the usual weather in the area...

s and cold wave

Cold wave

A cold wave is a weather phenomenon that is distinguished by a cooling of the air. Specifically, as used by the U.S. National Weather Service, a cold wave is a rapid fall in temperature within a 24 hour period requiring substantially increased protection to agriculture, industry, commerce, and...

s. Shorter-term climate oscillations typically do not directly result in climate change

Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

. However, the effects of underlying climate trends such as recent global warming

Global warming

Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...

 and oscillations can be cumulative to global temperature, producing shorter-term fluctuations in the instrumental

Instrumental temperature record

The instrumental temperature record shows fluctuations of the temperature of the global land surface and oceans. This data is collected from several thousand meteorological stations, Antarctic research stations and satellite observations of sea-surface temperature. Currently, the longest-running...

 and satellite

Satellite temperature measurements

The temperature of the atmosphere at various altitudes as well as sea and land surface temperatures can be inferred from satellite measurements. Weather satellites do not measure temperature directly but measure radiances in various wavelength bands...

 temperature record

Temperature record

The temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time. The most detailed information exists since 1850, when methodical thermometer-based records began. There are numerous estimates of temperatures since the end of the...

s.

External links

• El Niño's Extended Family: An Introduction to the Cyclic Patterns that Determine Global Weather - NASA Earth Observatory
• Earth Changes Gallery: Climate Oscillations - Michael Wells Mandeville
• 5.2 Internal climate variability - Catholic University of Louvain
• Understanding global climate patterns - USA Today, April 19, 2006
• Natural Climate Oscillations of Short Duration and the Long Term Climate Warming - Sorting Out the Climate System - USGCRP, March 20, 2000
• Oceanic and Atmospheric Climate Data - Climate Prediction Center, NOAA
• Global Climate Change: Vital Signs of the Planet - NASA Climate Website