北极地区20世纪温度变化趋势的不确定性

北极作为地球的冷源之一,对于地球气候系统起着重要的调节作用.本研究通过分析和总结北极地区器测数据和模拟集成结果,以及最近2 000 a来的温度记录,得出如下结果：1）格陵兰冰盖表层大气温度记录显示,20世纪存在1923—1965年和1994年—至今2个相对温暖时段,且前者更为温暖,温度变化幅度远大于北半球的平均温度.2）北极地区20世纪温度上升是客观存在的,其夏季温度和年平均温度呈现一致变化,未发现明显的温度异常信号.3）定量重建的古气候记录显示了北极地区20世纪升温的特征,但不同记录揭示的升温幅度存在差异.与器测结果不同,多条重建记录未能揭示自1994年至今的升温阶段,反映了古气候载体对气候响应的复杂性,揭示出北极地区未来气候变化趋势存在不确定性.在全球变化备受关注的背景下,北极地区对气候变化研究的重要性日益显现,在做出明确结论之前,需要进一步加大研究力度.

Uncertainty of Temperature Variability in the Arctic of the 20th Century

As one cold source of the earth,the Arctic plays an important role in its climate system.The study analyzes and summarizes temperatures from meteorological station and modeling,and temperature records of the past two thousand years in the Arctic.The results show：1）The near-surface air temperature anomalies of Greenland Inland ice show a larger change amplitude than Northern Hemisphere,and two warm periods,including 1923—1965 and 1994—present in the 20th century,can be identified,among which the former is warmer;2）The temperature in the Arctic was going up in the 20th century,with its average temperature of summer and annual showing a consistent variability and no significant anomaly signals of the temperature could be found between them;3）The quantitative reconstructions of paleo-temperature in the Arctic showed a warming trend in the 20th century,but there was amplitude discrepancy in the variability of temperature.A number of records failed to reveal a warming phase from 1994 to the present,reflecting high complexity between the paleoclimate proxy and climate system.All these facts reveal the uncertainties in the trend of future climate change in the Arctic.In the context of global climate change,the importance of related research in the Arctic is increasing.However,much more work must be done for getting definite conclusions.