Extreme Temperature Change of the Last 110 Years in Changchun, Northeast China

Abstract

In China and East Asia, the long-term continuous observational data at daily resolution are insufficient, and thus there is a lack of good understanding of the extreme climate variation over the last 100 years plus. In this study, the extreme temperature indices defined by ETCCDI (Expert Team on Climate Change Detection and Indices) and local meteorological administrations were analyzed for Changchun City, Northeast China, by using the daily maximum temperature (T_max) and daily minimum temperature (T_min) over 1909–2018. The results showed that extreme cold events, such as cold days, cold nights, frost days, icing days, and low temperature days, decreased significantly at rates of −0.41 d (10 yr)⁻¹, ⁻¹.45 d (10 yr)⁻¹, −2.28 d (10 yr)⁻¹, ⁻¹.16 d (10 yr)⁻¹ and ⁻¹.90 d (10 yr)⁻¹, respectively. Warm nights increased significantly at a rate of 1.71 d (10 yr)⁻¹, but warm days decreased slightly and the number of high temperature days decreased at a rate of −0.20 d (10 yr)⁻¹. The frequency of cold surge events increased significantly at a rate of 0.25 d (10 yr)⁻¹, occurring mainly from the mid-1950s to late-1980s. The average T_max, average T_min and extreme T_min increased at rates of 0.09°C (10 yr)⁻¹, 0.36°C (10 yr)⁻¹ and 0.54°C (10 yr)⁻¹, respectively; and extreme T_max decreased significantly at a rate of −0.17°C (10 yr)⁻¹. In 1909−2018, 1951−2018 and 1979−2018, the indices related to cold events decreased, while the trends of the indices related to warm events were different for different periods.

摘 要

在中国和东亚地区, 具有日分辨率的长期连续观测数据还十分缺乏, 因此对过去一百多年极端气候变化特征了解仍然不够. 利用1909-2018年的逐日最高、 最低气温资料, 以及ETCCDI(Expert Team on Climat Change Detection and Indices)和当地气象部门定义的极端气温指数, 本文分析了长春市过去110年极端气温指数变化特征, 结果表明: 冷日、 冷夜、 霜冻日数、 结冰日数、 低温日数等极端冷事件分别以−0.41 d (10 yr)⁻¹、 −1.45 d (10 yr)⁻¹、 − 2.28 d (10 yr)⁻¹、 −1.16 d (10 yr)⁻¹和 −1.90 d (10 yr)⁻¹ 的速率显著减少, 暖夜以 1.71 d (10 yr)⁻¹ 的速率显著增加, 高温日数以 −0.20 d (10 yr)⁻¹ 的速率减少, 暖日日数略有减少; 寒潮事件频数以0.25 d (10 yr)⁻¹ 的速率增多, 且多发时段主要集中在1950s中-1980s中后期; 平均最高气温、 平均最低气温和极端最低气温分别以0.09℃ (10 yr)⁻¹、 0.36℃ (10 yr)⁻¹和 0.54℃ (10 yr)⁻¹ 的速率明显升高; 极端最高气温以−0.17℃ (10 yr)⁻¹ 的速率显著降低; 1909-2018年、 1951-2018年、1979-2018年三个时段, 与冷事件有关的极端气温指数均减少, 与暖事件有关的极端气温指数, 因研究时期不同变化趋势差别明显.