基于树轮宽度重建的河南石人山地区1850年以来季节最低温度及20世纪增温

摘要

气候变化影响农业生产和相应的管理活动。中原地区位于我国中部，地域广阔，是我国重要的粮食生产基地。了解这一地区的历史气候变化极为重要。目前我们对这一地区过去几百年气候变化历史的了解主要来自于历史文献记载，缺乏自然地质记录的证据。本研究从河南石人山地区获取了一组油松树轮样本，在树轮宽度和现代气象观测记录统计相关分析的基础上，建立转换方程，重建了石人山地区1850—2011年上年10月至当年6月的平均最低温度。重建对观测温度（1958—2011年）的解释方差达到48.8%。重建中较暖时段有1892—1906年和1995—2011年；较冷期主要发生在1875—1890年、1910—1932年和1967—1980年。石人山地区自20世纪10年代以来持续增温，20世纪80年代以后增温更为显著（重建的10个高温年中9个都出现在1998年之后），表明石人山地区的温度重建结果能够捕捉20世纪以来的全球变暖信号。树轮宽度和温度的正相关关系也表明如果石人山地区未来持续变暖，将为油松的生长创造有利条件。本文重建中的冷暖时段与研究区附近其他地区温度序列中的冷暖时段较为一致，表明我国中部温度变化在较大区域范围内较为同步。空间场分析进一步证实了上述分析。此外，重建温度与全球海温（SST）的空间场分析表明石人山地区温度变化与西太平洋海温、印度洋和北大西洋海温变化密切相关。%Climate change inlfuences agriculture production and corresponding management activities. It is very important to understand climate variation in the vast regions of the Central Plains of China, an important crop production base. Current knowledge of the climate changes that have occurred in the past few hundred years in this region is primarily based on historical documents, and there is a shortage of evidence from natural archives. Based on a signiifcant correlation between the width of Chinese Pine tree rings and instrumental data obtained at Shiren Mountains (SRM), China, this study formulates a transfer function to reconstruct the mean minimum temperature (MMinT) from the previous December to the current June (Tmin_DJ) for the period of 1850—2011. This reconstruction explains 48.8% of the instrumental variance during the calibration period of 1958—2011. HighTmin_DJ intervals occurred during 1892—1906 and 1995—2011, and low intervals occurred during 1875—1890, 1910—1932 and 1967—1980. A distinct upward trend in theTmin_DJ series beginning in the 1910s was apparent, and the distinct warming happened after the 1980s (nine of the top ten years with the highestTmin_DJ values occurred after 1998, indicating that 20th century warming signal was captured well by the temperature reconstruction in the SRM region. The positive relationship between tree rings andTmin_DJ indicates that it will benefit plant growth and forest coverage in the SRM region if the warming trend continued. TheTmin_DJ reconstruction also matched several other temperature series in China, exhibiting similar warm-cold patterns. The distinct spatial correlation between both observed and reconstructed series and CRU TS 3.21 grid data indicates that our results might representTmin_DJ changes on a larger scale. The spatial correlation with sea surface temperature (SST) indicates that observed and reconstructedTmin_DJ temperatures in the SRM area are closely linked to the SST variability in the West Paciifc, Indian and North Atlantic Oceans.