关键词: 0cm地温, 平均气温, 气候变化, 东北三省, 地气温差

Abstract:

Based on daily observations of 0cm ground temperature and average temperature from 78 meteorological stations in the three provinces of northeast China (Heilongjiang, Jilin and Liaoning) from 1961 to 2020, this study employed trend analysis and correlation analysis to analyze the spatial−temporal variation characteristics of 0cm ground temperature and average temperature in the region. The results showed that the high−value areas of 0cm ground temperature were distributed further north compared to that of average temperature from 1961 to 2020. From 1991 to 2020, high−temperature zones for both 0cm ground temperature and average temperature shifted northward relative to that of in the period 1961−2020. The decadal tendency of 0cm ground temperature and average temperature during 1961−2020 were 0.75℃·10y⁻¹ and 0.30℃·10y⁻¹, respectively, with significant level of 0.01. The increasing trend of 0cm ground temperature during 1991−2020 (1.30℃·10y⁻¹) was higher than that of 1961−1990 (0.20℃·10y⁻¹), whereas the trend for average temperature (0.15℃·10y⁻¹) was lower than that of 1961−1990 (0.27℃·10y⁻¹). The seasonal decadal tendency of 0cm ground temperature during 1961−2020 were 0.56℃·10y⁻¹ in spring, 0.37℃·10y⁻¹ in summer, 0.49℃·10y⁻¹ in autumn and 1.54℃·10y⁻¹ in winter, with the significant level of 0.01. It showed a slight trend during 1961−1990 but a significant increasing trend during 1991−2020. The seasonal decadal increasing trend of average temperature during 1961−2020 were 0.35℃·10y⁻¹ in spring, 0.21℃·10y⁻¹ in summer, 0.26℃·10y⁻¹ in autumn and 0.41℃·10y⁻¹ in winter, with the significant level of 0.01. During the period of 1991−2020, the increments for spring, summer and autumn were larger than those of in the period 1961−1990, while the winter increment was smaller. From 1961 to 2020, correlations between 0cm ground temperature and average temperature for annual and seasons in the three provinces of northeastern China were extremely significant, with correlation coefficients being 0.99, 0.95, 0.88, 0.99 and 0.98, respectively. The differences between 0cm ground temperature and average temperature from 1961 to 2020 were 2.1℃ annually, 2.3℃ in spring, 3.8℃ in summer, 1.3℃ in autumn and 0.9℃ in winter. The difference was greater in 1991−2020 than that in 1961−1990, and was largest in summer, followed by spring, autumn and winter. 

Key words: 0cm ground temperature, Average temperature, Climate change, The three provinces of northeast China, Difference between 0cm ground temperature and air temperature