Observations of the 18.6-year cycle of air pressure and a theoretical model to explain certain aspects of this signal
| ISSN: |
1432-0894
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| Source: |
Springer Online Journal Archives 1860-2000
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| Topics: |
Geosciences
Physics
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| Notes: |
Abstract Evidence from barometric data in Japan, USSR, southern Europe, southern Africa, and South America shows that air pressure variations with period near 18.6-years can attain amplitudes as high as 0.9 mb, and are identified as induced by the luni-solar constituent tide M n (M for moon and n for nodal). Luni-solar waveforms commonly exhibit modulation effects due to the superposition of a longer period component with 180° changes in phase. Thus, the waveform amplitudes can be highly nonstationary. Pressure gradients at this period over subcontinental distances show that the amplitudes imply nonequilibrium conditions. A theoretical coupling mechanism between E-W and N-S wind systems and the Coriolis force is envoked to explain the sub-continental extent and the, sometimes abrupt, amplitude changes of the pressure systems over small distances.
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| Type of Medium: |
Electronic Resource
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| URL: |