Interdecadal and decadal variation of temperature over North Pole area and the relation with solar activity
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Interdecadal and decadal variation of temperature over North Pole area and the relation with solar activity QU Weizheng1∗ , ZHAO Jinping1 , DU Ling1 , HUANG Fei1 , FAN Tingting1 1
Ocean University of China, Qingdao 266003, China
Received 13 June 2010; accepted 2 December 2010 ©The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2011
Abstract 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 ◦ C for about 50 years at a speed about 0.025 ◦ C/year in January, and 0.013 ◦ C/year in July. The air temperature in the middle layer of the stratosphere (10 hPa) in January has increased 10 ◦ C. The temperature rising speed in July is 0.14 ◦ C/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 ◦ C for about 50 years at a temperature decreasing speed about 0.094 ◦ C/year, and at a temperature decreasing speed about 0.032 ◦ C/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. Key words: decadal variation of air temperature, solar activity, North Pole area
1 Introduction The latitude of the North Pole area is higher than 62.5 N. The absorption of the sun radiation is much less in the North Pole area than that in the middle and low latitudes. For example, the temperature records of the tundra in Alaska indicate that the average air temperature has increased 2–4 ◦ C for about a century(GRIP,1993). The air temperature in summer at Barrow and Prudhoe Bays in Alaska has increased linearly since the 1970s. At Prudhoe Bay, this rising tendency is even more obvious. The temperature increased from 4.1 ◦ C in 1969 to 6.9 ◦ C in 1990. It increased 2.8 ◦ C in the 21 years. The increasing speed is 0.13 ◦ C/year. The temperature records in the recent 74 years indicate that the annual average temperatures at Balo Cape,
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