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In this study, 89 records of spring phenophases of plants and lake melting dates in Beijing from A.D. 1741 to 1832 were extracted from the poems written by the Qianlong, Jiaqing, and Daoguang emperors during the Qing Dynasty. Based on a phenology transformation model, all of these spring phenological records were converted into the first blooming date of Amygdalus davidiana for A.D. 1741–1832. Then, a springtime temperature anomaly series for A.D. 1741–1832 was reconstructed based on modern (1951–1980) correlation between the first blooming date of A. davidiana and the mean springtime (March–May) temperature. The main results are as follows. (1) The spring phenological and temperature series for Beijing were successfully dated back to A.D. 1741. (2) A.D. 1790 was the turning point of the spring phenology change between 1741 and 1832; specifically, the average first blooming date of A. davidiana had advanced by 4.84 days compared to the present (A.D. 1951–1980), during 1741 to 1789, and was delayed by 0.14 days during 1790 to 1832. (3) The mean springtime temperature in A.D. 1741–1789 was about 0.48 °C warmer than the present (A.D. 1951–1980) in Beijing. (4) The annual-scale variation of the phenological series during A.D. 1790–1832 was greater than that in A.D. 1741–1789.

Daily weather records from a historical private diary provide important data for studying historical climate change. We compiled daily weather records from the Weng Tong-He Diary and counted the number of monthly precipitation days during 1860-1897 AD for Beijing; then, using the number of monthly precipitation days, we reconstructed the seasonal precipitation using regression models relating the precipitation and precipitation days. The findings show that the monthly mean number of precipitation days for 1860-1897 was greater than that for 1951-2009 by about 1 d month1 and that the summer (June to August, JJA) precipitation for 1860-1897 was 471.8 mm greater than that for 1951-2009 by about 15.5%. The JJA precipitation of 1860-1897 had not only inter-annual variations but also inter-decadal variations that were characterized by less precipitation before 1886 (about 421.9 mm) and more precipitation thereafter (about 550.7 mm). As a consequence, the JJA precipitation of 1860-1897 showed an evident positive trend with a rate of about 57.9 mm per decade. These precipitation variations were confirmed by other datasets. However, it is worth noting that our reconstruction underestimates the historical precipitation values (by about 22.5%) because of rainfall/snowfall events missed in Weng's diary and the poor ability of the regression models to capture extreme years. In the future, new methods of reconstructing precipitation with the consideration of missed rainfall/snowfall events are needed. Copyright (c) 2012 Royal Meteorological Society

Much effort has been spent in the last few decades to reconstruct the climate over China using a variety of historical documents. However, differences in the results of reconstructions exist even when people are using similar documents. In order to address this issue, 14 published temperature series by different studies were analyzed for coherence and mutual consistency. The analyses on their temporal fluctuations indicate that for the individual time series (standardized) on the 10-years time scales, 57 of the 91 correlation coefficients reach the significance level of 99%. The spatial patterns among the different time series also show high coherency. In addition, consistency also exhibit when comparing the reconstructions with other available natural climate change indicators. Above information was subsequently used to synthesize the temperature series for the last 500 and 1000 years. Copyright (C) 2007 Royal Meteorological Society.