东台市近72年四季起始日期及长度演变特征分析

Analysis of the Evolution Characteristics of the Seasonal Onset Dates and Duration in Dongtai City over the Past 72 Years

摘要: 对东台1953年到2024年四季起始日期及持续时间进行特征分析，揭示东台四季变化时间对全球气候变暖的响应。结果表明：东台市近72年四季开始的时间分别是3月28日、6月1日、9月23日、11月21日，四季的长度分别是65、114、59、127 d。春季和夏季开始时间逐渐提前，秋季和冬季开始时间逐渐推后。其中春季提前时间最为明显，每10年提前2.5 d。春季和夏季持续时间呈现增长趋势，秋季和冬季持续时间逐渐减少，夏季和冬季最为明显。夏季平均每10年增加3.2 d，冬季平均每10年减少3.5 d。四季持续时间异常情况明显高于季节早晚等级。

Abstract: This study analyzes the spatiotemporal characteristics of the seasonal onset dates and durations in Dongtai City from 1953 to 2024, exploring its response to global warming. Results indicate that the average onset dates of spring, summer, autumn and winter in the past 72 years were March 28, June 1, September 23 and November 21, with corresponding durations of 65, 114, 59 and 127 days. Spring and summer onset advanced progressively, while autumn and winter onset delayed; Spring advanced most notably (2.5 d/10a). Spring and summer durations increased, whereas autumn and winter durations shortened, with the most prominent changes in summer (3.2 d/10a) and winter (−3.5 d/10a). Abnormalities in seasonal durations were significantly more pronounced than those in seasonal onset timing.