What causes the Arctic Oscillation?

The polar vortex does not come and go; it is a permanent feature of the Earth system. Still, the vortex’s shape changes over time, affected by shifts in atmospheric pressure and temperature. Scientists describe these pressure and temperature shifts as changes in the AO.

What is the Arctic Oscillation for kids?

The Arctic Oscillation is the movement of air back and forth between the North Pole area and the areas farther south—like down to the middle of the U.S. Sometimes the air pressure is higher in the south so the warmer air pushes north, and keeps the really cold Arctic air in the Arctic.

What phase is the Arctic Oscillation in?

Periodicity. Over most of the past century, the Arctic oscillation alternated between positive and negative phases. Data using a 60-day running mean has implied the oscillation has been trending to more of a positive phase since the 1970s, though it has trended to a more neutral state in the last decade.

What is an oscillation in weather?

Climate oscillations are the naturally reoccurring changes of earth’s climate that are associated with the interactions of atmospheric and oceanic conditions and occur over different geographic scales and time periods.

How long is Arctic Oscillation?

Seasonal (3-month) values for the Arctic Oscillation Index, which tracks shifts in surface pressure between the mid-latitudes and the Arctic. During the positive phase, the jet stream stays farther north, and mid-latitude winters are milder than usual.

Is the Arctic Oscillation the same as the polar vortex?

The configuration of the polar vortex is linked to the phase of the Arctic Oscillation, a seesaw pattern of rising and falling atmospheric pressure over the Arctic and the middle latitudes. When the Arctic Oscillation switches to a positive phase, the polar vortex tends to extend toward the pole.

What is oscillation in geography?

Southern Oscillation, in oceanography and climatology, a coherent interannual fluctuation of atmospheric pressure over the tropical Indo-Pacific region. The Southern Oscillation is the atmospheric component of a single large-scale coupled interaction called the El Niño/Southern Oscillation (ENSO).

What are the known natural oscillations of climate patterns?

Scientists have uncovered evidence for another natural cycle that, like El Niño and La Niña, shifts Pacific Ocean winds and currents and rearranges rainfall and weather patterns around the globe. The newly detected cycle recurs every 100 years, less frequently than the two-to-seven year El Niño-Southern Oscillation.

What is Arctic Oscillation Index?

The Arctic Oscillation (AO) is a climate index of the state of the atmospheric circulation over the Arctic. It consists of a positive phase, featuring below average geopotential heights , which are also referred to as negative geopotential height anomalies , and a negative phase in which the opposite is true.

Is the Earth changing?

Our restless Earth is always changing. Tectonic plates drift, the crust quakes, and volcanoes erupt. Air pressure falls, storms form, and precipitation results. Learn how these powerful forces shape our air, land, water, and weather—and constantly transform our planet.