【摘要】 本文尝试由历史文献记载直接反演网格式降水量距平场。这项探讨是利用计算机的文字处理功能 ,以“中国三千年气象记录总集”1 ) 为基本资料 ,通过对各地点、各年份气候记载的赋值处理 ,用Cressman插值方法初步反演生成 1 50 1～ 1 90 0年网格降水量距平场 ,其时间分辨率为 1a,空间分辨率为 1°× 1°经纬度。这样的网格资料定量含义明确 ,空间和时间的连续性好 ,可以方便地与数值模拟结果进行对比 ,和进行降水的时间、空间变率研究 ,还可由它生成空间间隔均匀的降水量距平指数的时间序列 ,进行气候变化分析。更多还原

【Abstract】 The reconstruction of past precipitation from historical documents has been made recently. Computer processed the historical records automatically. Indices of annual precipitation anomaly were obtained, and then interpolated into grid result. The spatial resolution is 1°(latitude)×1°(longitude). The annual precipitation distribution in eastern China has been reconstructed for the period of 1501～1900A.D. Time series for several certain regions were obtained. The results can be used in the study of climate change, and can also be compared with numerical modeling results. 1 Data The historical records used in this study are from "A compendium of Chinese meteorological records of the last 3 000 years". The historical period of 1501～1900A.D. was selected for analysis. Site corrections have been made for all records. The locations were expressed in latitudes and longitudes. 2 Methodology The grid result was obtained following steps as below: (1) Typical words. Typical words related to climatic conditions ( i.e ., rain, drought, flood, etc.) were selected from the historical records and divided into different categories; they can be processed automatically on computer, by extracting typical words from each record and converting them into numerical codes. (2) Indices. Index values were assigned to each record according to the climatic information extracted. 1, 0, -1 were referred as positive anomaly, normal, and negative anomaly of annual precipitation, respectively. 0 was assigned to a record that indicates both drought and flood occurred within one historical year at the same magnitude; 0 was also assigned when a record contains no information about drought or flood, but a good harvest indicating a normal annual precipitation. (3) Interpolation. A Cressman objective analysis was performed on the station data to yield a grid result. (4) Express the interpolated result as +1, 0, -1. (5) Map plotting. GrADS (the grid analysis and display system) were used to plot annual precipitation anomaly maps. Blue, green and red colors are referred as positive anomaly, normal, and negative anomaly, respectively. 3 Preliminary results Annual precipitation anomaly maps for eastern China during 1501～1900A.D. have been obtained. These maps can be compared conveniently with numerical modeling results.更多还原