Abstract:

Based on the daily temperature in winter from 56 meteorological stations from 1961 to 2020 in Liaoning province, the temporal and spatial change in the average temperature and the climatic characteristics of warm winter events at a single station and the region scale were analyzed using climate tendency rate, IDW, sliding t test mutation analysis and wavelet analysis methods.According to the national standards of warm winter, the climate value in 1990-2020 was selected as the reference one.The results show that the average temperature in winter in Liaoning province increases at a rate of 0.3℃ per decade in recent 60 years.The warming trend is most significant in the central and eastern Liaoning province.In the first 30 years of the 1990s, it is a relatively cold period, but its warming effect is stronger than that in the last 30 years.The average temperature in winter shows an obvious abrupt change from cold to warm in around 1987.There is a relatively weak change from cold to warm in 1971.After 1988, the occurrence of warm winter events at a single station increases significantly compared with that in 1961-1987.The high frequency of warming events mainly happens at the central and southeast parts of Liaoning province, with 16-20 warming winter events.There are sixteen times of regional warming winter events in the recent 60 years.In the first 20 years after the 21st century, there are nine times of regional warm winter events, accounting for 60% of the total events.Regional warm winter events oscillate in periods of quasi-22 years and 2-3 years.

Key words: Winter temperature, Warm winter index, Warm winter frequency