^THE PATTERNS OF TEMPERATURE AND SEA LEVEL PRESSURE IN VARIOUS COLD AND WARM PERIODS WITH IN RECENT 100 YEARS

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  • Institute of Atmospheric Physics. Chinese Academy of Sciences. Beijing 100080

Received date: 1994-03-01

  Revised date: 1994-07-01

  Online published: 1995-03-15

Abstract

In order to predicl the future climate tendency. it is necessary to investigate the history of climate evolution. especially for the last hundred years. This paper studies the patterns of global temperature. sea level pressure during two special warm periods (1936-1945 and 1979-1988)and two special cold periods(1906-1915 and 1966-1975) . The main conclusions are as follow :(1) The global climate has been warming up in the last hundred years. The period of 1906-1915 was the coldest decade and the period of 1979-1988 was the most warm in this century.The global temperature had experienced two abrupt warming events during 1920s’ and by the end of 1970s’. However there was an abrupt cooling by 1960s’. The changes of temperature over the land areas are generally earlier than those over the ocean areas the temperature patterns show that the signs of temperature were opposited between land and ocean and between northern and southern hemispheres during the warm period of 1936-1945 and the cold period of 1966-1975 after the abruupt changes. The abrupt changes of Asian and African monsoon accompanied with the transformation of precipitation pattern during the mid 1960s’ were responsiable to the temperature contrast between land and sea. as the temperature over the northern continents began to decrease. while the oceans continued warming up.(2) The temperature patterns were different between these two warm periods and also between the two cold periods. However, they had a similar feature. the temperature variability centers located over continent in the northern high latitudes. especially at Alaska and Northern Asia.(3) The sea level pressure fields display quite a different characters related with the temperature variation. In the cold period. the winter Mongolia high in Eurasian continent is intensified, and the North American ridge shifted westward. Over the northern oceans. the Iceland Low is weakened together with the deepened Aleution Low. The patterns were on the contrary during the warm periods.(4) The results of harmonic analysis on zonal temperature field show that. during the warm periods, the ultra-long wave were more active than the long wave, while during the cold period the situation were opposite.(5)We should not overlook the synthetical role of natural factors when we predict the future climate tendency in response to the increase of the concentration of greenhouse gas.

Cite this article

Zeng Zhaomei, Zhang Mingli, Ji Jinjun . ^THE PATTERNS OF TEMPERATURE AND SEA LEVEL PRESSURE IN VARIOUS COLD AND WARM PERIODS WITH IN RECENT 100 YEARS[J]. Acta Geographica Sinica, 1995 , 50(2) : 147 -159 . DOI: 10.11821/xb199502006

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