南极洲伊丽莎白公主地区250年来气候环境变化研究

利用 1996 / 1997年中国首次南极内陆冰盖考察获得的 5 0m雪芯资料 ,恢复了南极洲伊丽莎白公主地区 2 5 0年来的气候变化情况 :2 5 0年来 ,伊丽莎白公主地区的积累率和气温大致可以 186 0年为界分为两段 ,186 0年以前气温和积累率都呈现上升趋势 ,而 186 0年以后气温明显降低 ,积累率变化不明显。同时 ,从 2 5 0年的时间尺度考察近半个世纪以来气温和降水的结果表明 ,虽然目前两者都呈现上升的趋势 ,但都不是历史上的最高值。 2 5 0年来的大气环境变化研究表明 :δ18O与NO-3 、nssSO2 -4 浓度变化表现出一定程度的负相关性 ,即冷期时这两种离子的浓度都较高 ,暖期时浓度低 ,这可能是冷期经向环流加强从而有利于其从中、低纬度传输的缘故 ;而海盐离子Cl-、Na+ 和Mg2 + 与δ18O无任何相关关系 ,可能反映了本地区雪冰中的海盐离子主要来源于周边海洋地区的降水。

A STUDY OF CLIMATE AND ENVIRONMENT IN PRINCESS ELIZABETH LAND,ANTARCTICA IN THE PAST 250 YEARS

The 50-meter firn core drilled at the destination of the route of the 1996/1997 Chinese First Antarctic Inland Expedition in Princess Elizabeth Land, East Antarctica, has been measured for δ 18 O and major ions. Based on the data, the features of the climate change in the study region in the past 250 years have first been studied. In the past 250 years, the climate trend in the region can be divided into two stages by the year 1860, both the temperature and accumulation rate increased before 1860, but after 1860, the temperature decreased obviously while the variation of accumulation rate was not discernible. Although both the temperature and accumulation rate have been increasing in the past 50 years, they are not the highest values in the past 250 years. The results of the atmospheric environmental change in the past 250 years show that the variations of δ 18 O and NO - 3 ,nssSO 2- 4 have some negative correlation.That is, the concentrations of NO - 3 and nssSO 2- 4 were higher during cold conditions than those during warm conditions, which may reflect strengthened transport during cold conditions linked to higher wind speed. On the contrary, there is no correlation between δ 18 O and sea-salt ions, reflecting that the sea-salt ions in Princess Elizabeth Land come from the sea around them.