清代华北地区冬半年温度变化重建与分析

利用清代地方志中的异常初、终霜记载,根据器测时期华北初、终霜的早、晚与温度变化的关系,重建了1646-1910 年华北地区时间分辨率为5 年的冬半年温度距平序列,分析了期间的冷暖变化特征.结果表明：清代华北地区气候以寒冷为主要特征,冬半年温度平均较现代(1951-1980 年)约低0.55℃,最冷5 年(1656-1660 年)较现代约低1.42℃;清代华北地区冬半年气候存在“冷-暖-冷”的世纪波动,两个寒冷时段起讫时间分别为1646-1700 年(平均较现代约低0.77℃)和1781-1910 年(平均较现代约低0.58℃),1701-1780 年虽然相对较暖,但冬半年温度仍较现代略低(平均较现代约低0.36℃);从更高时间分辨率看,清代冷暖时段内同样存在较小的波动,清后期寒冷时段出现了两个“冷谷”.

Reconstruction and Analysis on the Series of Winter-half-year Temperature Change during the Qing Dynasty in the Northern China Region

Based on the records of irregular first and last frost dates from the historical documents during the Qing Dynasty, the winter-half-year temperatures in northern China region are reconstructed at a five-year resolution by applying a conversion function to the historical records obtained from examining the correlation between the changes of first and last frost dates and the changes of instrument-measured regional mean temperatures in more recent years. The characteristics of temperature changes in that period are analyzed. The results indicate that: (1) the climate in northern China region in the Qing Dynasty can be characterized as cold. The mean winter- half-year temperature of that time period in the region is 0.55℃ lower than that of the present time (1951-1980), with a 1.42℃ difference in the coldest five years (1656-1660). (2) The centennial scale climate variations show a“cold-warm-cold”pattern. The two cold periods appear around 1646-1700 and 1781-1910, when the winter-half-year temperature in northern China region is about 0.77℃ and 0.58℃ lower than that of the present days respectively. During the period of 1701-1780, the climate is relatively warm, but the winter- half-year temperature is still lower than that of the present days (by 0.36℃ difference). (3) At a higher time resolution, relatively small temperature fluctuations are observed within each cold and warm time period, with two“cold troughs”during the late Qing Dynasty (1781-1910).