Abstract:
The temporal and spatial variation characteristics of 0cm surface temperature in Sichuan and Chongqing were analyzed based on the daily average surface temperature, maximum surface temperature and minimum surface temperature data of 53 surface meteorological observation stations in Sichuan and Chongqing from 1980 to 2018. The results showed that surface temperature in winter in the study area showed a warming trend, and the increase of daily minimum surface temperature (0.79℃/10a) were higher than daily maximum surface temperature (0.37℃/10a). The daily average, daily maximum and daily minimum surface temperature and diurnal range of surface temperature in the Southwest Sichuan Mountains and the Sichuan Basin showed a warning trend, and the warming rate in the Southwest Sichuan Mountains was higher than that in the Sichuan Basin. The daily minimum surface temperature in the Northwest Sichuan Plateau had the highest rate of increase (1.43℃/10a), and the daily maximum and diurnal range of surface temperature both showed a downward trend, at −0.24℃/10a and −1.21℃/10a, respectively. The abrupt surface temperature showed significant regional differences in winter, the abrupt change point of the Northwest Sichuan Plateau, the Southwest Sichuan Mountains and the Sichuan Basin were 2003, 1993 and 1989, respectively, that is, the higher the regional altitude is, the more delayed the warming mutation occurs, and the warming trend after the mutation in the Sichuan Basin is relatively weak.The daily average 0 cm ground temperature in winter in Sichuan-Chongqing region showed significant chronological shock characteristics on different time scales. The variation periods were 4~7 a, 10~15 a and 23~26 a, of which the main period was quasi-24 a and the sub-period was quasi-11 a.