1981-2024年广东省气候季节时空分布及其演变特征OA

Seasonal variations reflect the regular annual changes in global and regional climate patterns,serving as important references for human activities and planning.Focusing on Guangdong Province,this study analyzed onset dates and lengths of different climatic seasons across historical years using daily average temperature observations from 86 national meteorological stations from 1981 to 2024,adhering to the Chinese industry standard"Climate Season Classification(GB/T 42074-2022)".Using linear regression analysis and trend coefficient statistical methods,we systematically investigated the spatiotemporal distribution and changing patterns of climatic seasons in Guangdong,quantifying their responses to regional climate change.The findings are as follows:1)Most of Guangdong Province belongs to a"winterless"zone,with only the northernmost part being a four-distinct-season zone.2)Significant spatial heterogeneity exists in the onset dates of climatological normal seasons.Within the four-distinct-season zone,spring begins earlier in the south and later in the north,while winter starts earlier in the north and later in the south.On average,summer and autumn commence on April 10 and October 31,respectively.The climatological lengths of spring,summer,and autumn are 94,204,and 62 d,respectively,while winter lasts for 40 d in the four-distinct-season zone.3)From 1981 to 2024,in the four-distinct-season zone,the onset of spring and summer showed a slight advancing trend,while those of autumn and winter were slightly delayed,with no significant changes in season lengths.In the winterless regions,however,summer onset advanced significantly at a rate of 2.49 days per decade,while autumn onset was significantly delayed by 2.22 d per decade.This led to a significant shortening of both spring and autumn lengths and the significant extension of summer length by 4.71 d per decade.These trends reached statistical significance at the 0.01 level in some southern coastal regions.