甘肃中部地区地–气温差时空变化特征

Spatiotemporal Variation Characteristics of Surface-Air Temperature Difference in Central Gansu Region

摘要: 为研究甘肃中部地区地气温差时空变化特征，利用该区域1971~2024年22个国家气象站逐日0 cm地温与气温资料，采用REOF、Morlet小波、Mann-Kendll法和回归分析等方法进行综合分析。结果表明，地气温差空间分布有明显区域差异，分为I区、II区和III区，且自南向北逐渐减小；年际变化I区、III区不显著，II区更显著呈增加趋势，I区、II区自20世纪90年代至21世纪00年代呈上升趋势，之后10年代呈下降阶段；III区自20世纪80年代中期以来，一直在波动中呈缓慢的下降阶段，目前，均处于上升阶段的同相位变化；月际变化曲线呈现“单峰型”变化，最大值、最小值分别出现在当年的6月和12月，比地温和气温均提前了1个月，夏季最大、春季次之、秋季较小、冬季最小，I区、II区存在20~25a长周期，III区存在15~20a长周期。另外，I区和II区存在5a左右的短周期，III区存在8a左右的短周期，I区、II区、III区的突变年份分别为1980、1978、2015a。本文结论对科学认识甘肃中部地区生态环境的变化具有参考意义。

Abstract: To study the spatio-temporal variation characteristics of the ground and air temperature difference in the central region of Gansu Province, the daily 0cm ground temperature and air temperature data of 22 national meteorological stations in this region from 1971 to 2024 were utilized, and a comprehensive analysis was conducted using methods such as REOF, Morlet wavelet, Mann-Kendll method and regression analysis. The results show that there are obvious regional differences in the spatial distribution of air-ground temperature difference, which is divided into area I, area II and area III, and gradually decreases from south to north. The interannual changes were not significant in Zone I and Zone III, but more significant in Zone II, showing an increasing trend. Zone I and Zone II showed an upward trend from the 1990s to the 2000s, and then a downward stage in the 2010s. Zone III has been in a slow downward phase with fluctuations since the mid-1980s. Currently, it is in the same phase of an upward phase. The monthly variation curve shows a “unimodal” variation. The maximum and minimum values occur respectively in June and December of the current year, both one month earlier than the ground temperature and air temperature. The maximum value is in summer, followed by spring, the minimum in autumn and the minimum in winter. There is a long cycle of 20~25 years in Zone I and Zone II, and a long cycle of 15~20 years in Zone III. In addition, there is a short cycle of about 5 years in region I and region II, and a short cycle of about 8 years in region III. The mutation years of region I, region II and region III are 1980, 1978 and 2015 years respectively. The correlation degree of the temperature difference between the ground and the atmosphere with precipitation is higher in Zone I than in Zone III, and higher in Zone III than in Zone II. The correlation degree is high in summer and autumn, and even higher in summer. It is relatively lower in the annual period, and lower in winter and spring, and even lower in winter. The conclusion of this article has reference significance for scientifically understanding the changes in the ecological environment of the central region of Gansu Province.