Meteorologische Zeitschrift (Jul 2006)

A note on the global change in the 1970s

  • Harry van Loon

DOI
https://doi.org/10.1127/0941-2948/2006/0122
Journal volume & issue
Vol. 15, no. 3
pp. 365 – 370

Abstract

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The atmosphere changes among different states. For instance, a change took place in the second half of the 1970s, and the year of 1976 is generally considered the last year of a state that lasted from about 1942 till 1976. The tropical/subtropical mean sea surface temperature jumped from a lower to a higher mean, from before 1976 to after, mainly because its minima were higher after 1976. The geopotential heights in the troposphere closely followed the changes of the sea surface temperatures. At sea level in winter in the Northern Hemisphere the Aleutian low and the Icelandic low and its eastward extension deepened after 1976, whereas the pressure rose at lower latitudes. This was reflected in the lower stratosphere in the deepening of the polar low and rising heights in middle and low latitudes. In the winter of the Southern Hemisphere the Global Change at sea level took place in a pattern in which waves 1 and 3 dominated; also in this hemisphere pressure fell at higher and rose in lower latitudes. The correlation pattern between the solar decadal oscillation and the annual mean, zonally averaged geopotential heights in the lower half of the stratosphere reversed from the period before to the period after 1976.