摘要：

依据清代《翁同龢日记》中天气状况的描述，整理出公元1860～1898年间逐月的沙尘天气日数，基于记录完整月份的沙尘天气日数，统计分析了公元1860～1898年北京沙尘天气日数的平均状况和变化特征。分析发现公元1860～1898年，北京年均沙尘天气记录为10.4天，即使不考虑与现代观测记录标准的差别，亦肯定高于1990年代7.7天/年的平均频次；春季是沙尘天气的高发季节，其占全年沙尘日数的百分比达到70%，其中4月和5月两个月的接近53%；其次为冬季，占20%。与公元1961～2000年相比，公元1860～1898年的春季沙尘天气日数百分比偏高10.9%，沙尘天气在春季的集中程度明显偏高。公元1860～1898年间，年沙尘日数和春季沙尘日数均呈波动减少之势；研究时段内，共出现23次2天以上连续（或持续）的沙尘天气过程，最长的一次持续了4天。这些发现将有益于研究气候变化对沙尘天气影响和分析北京沙尘天气的演变规律。

Abstract:

An ancient diary named “Weng Tonghe Diary” written in the late Qing Dynasty by Weng Tonghe and edited by Chen Yijie was dug out in this paper. First of all, every sand dust record was extracted from this diary. Based on the records of full months, the general status and evolvement character of sand dust weather in Beijing during 1860~1898A.D. were analyzed statistically. It is found that, (1) The average sand dust days of Beijing during 1860~1898 A.D. are 10.4 days which are more than average frequency of 1990’s even ignoring the difference in the standard on sand dust. (2) Sand dust weather mainly arose in spring weight of which reaches 70%, in which the weight of April and May is over 50%; and winter is the second high frequent season weight of which is 20%. (3) Comparing with 1961~2000 A.D., sand dust process during 1860~1898A.D. was more highly concentrated in spring. (4) The trend of annual total number of sand dust days decreased from 1860 A.D. to 1898 A.D., so as to the number of dust days in spring. (5) During 1860~1898 A.D., there were 23 sand dust weather processes that were lasting longer than one day, of which the longest one lasted 4 days. These finds may be helpful to study the impact of climate change on sand dust weather and to analyze evolvement regulation of sand dust weather in Beijing.