Quasi-biennial oscillation

The quasi- biennial oscillation (short: QBO " quasi- biennial oscillation " from the English ), and quasi - biennial oscillation, is a quasi -periodic atmospheric wave of zonal wind in the equatorial stratosphere of the earth.

Occurrence

It shows at a height of around 16 to 40 kilometers, with a maximum at about 20 to 25 km altitude and is characterized by an east-west - wind reversal. The period varies since observations began in 1953, 22-34 months, the average period is 27 months. Your easterly phase continues in the upper layers of longer and shorter in the lower layers than their west wind phase. The easterly winds here are stronger than the westerly winds pronounced, which has a thickness of -30 m / s ( east wind ) to 15 m / s ( Westwind ) have.

History

In ascents of pilot and registration balloons of German meteorologist Arthur Berson 1908 observed westerly winds during his aerological expedition to East Africa in the lower stratosphere. This was in contradiction to the assumption that prevail at the equator at this altitude stable easterly winds, as they had been observed after the eruption of Krakatoa in 1883 with reference to the direction of pull of his smoke and dust cloud. This mystery remained unsolved at first, until the late 1950s radiosonde stations were set up near the equator during the International Geophysical Year. Initial data analysis indicated the existence of an oscillating zonal wind. The theory of the QBO was erected in 1968 by Richard Lindzen and Holton James Reed ( 1938-2004 ).

Importance

The QBO plays an important role in relation to the impact of the variability of solar activity on the Earth's atmosphere and thus also for the global climate.