On the basis of the EOF analysis of global geopotential height anomaly (GHA) field at 10 hPa level, the arctic oscillation (AO) and the means antarctic oscillation (AAO) can be detected more obviously at the upper level of atmosphere than the AO or the AAO in surface layer. Unlike the hemisphere pattern of the AO and the AAO in the surface lager given by previous authors, the AO or the AAO in the stratosphere has its global features. The zonal oscillations-the Southern Oscillation (SO) and the north oscillation (NO) in atmospheric surface layer become less clear in the upper air. The first mode (AO mode, abbreviated to AOM hereafter) and the second mode (AAO mode, abbreviated to AAOM hereafter) respectively have 41.47% and 27.04% of the total variance contribution. The cumulative variance contribution of the first two modes reaches 68.51%. These two modes are the main components for the interdecadal or decadal oscillation in the stratosphere. In addition, there still exist two kinds of oscillation patterns with less probability,namely, the symmetric pattern at mid-high latitudes in the Southern Hemisphere and the asymmetric pattern. Spectral analysis shows that the AOM and the AAOM all have a spectral peak for 22 a period, being consistent with the periodic variations of the solar magnetic field, and a peak for 11 a period, being consistent with the period of the numbers of sunspots. Step filter analysis shows that the influencing factor for the upper atmospheric oscillation is the solar activity. The fluctuation of the solar magnetic field is the more influencing factor than the variation of the sunspot number.
Obvious tendency and periodicity of the air temperature can be detected over the North Pole area. They are reflected as follows:a. the air temperature at the earth surface and in the middle layer of the stratosphere tends to be increased either in winter or in summer. The air temperature has increased 1.3℃ for about 50 years at a speed about 0.025℃/year in January, and 0.013℃/year in July. The air temperature in the middle layer of the stratosphere (10 hPa) in January has increased 10℃. The temperature rising speed in July is 0.14℃/year. Generally speaking, the temperature rising speed is quicker in winter than in summer and quicker in the upper layer than at the earth surface. b. The air temperature at the top layer of the troposphere (100 hPa) over the North Pole area tends to be increased either in winter or in summer. The air temperature in January has decreased 5.0℃ for about 50 years at a temperature decreasing speed about 0.094℃/year, and at a temperature decreasing speed about 0.032℃/year in July. The speed of the temperature decreasing is greater in winter than in summer. c. Periodicity. The air temperature respectively at different altitudes over the North Pole possesses interdecadal variation with a period of 22 years. In July the amplitude of the variation with a period of 22 years decreases rapidly from the high altitude to the low. This means that the 22-year's period is more obvious at the high altitude than at the low altitude. At the earth surface layer in North Pole there also is obvious decadal variation with a period of 11 years. The analysis indicates that the 22-years' period temperature variation is associated with the periodic variation of the solar magnetic field. The 11-year period temperature variation is corresponding to 11 year' period of the variation of the sunspot number.