1960—2024年呼伦贝尔市极寒天气特征分析

Characteristics of Extreme Cold Weather in Hulun Buir from 1960 to 2024

摘要:

本文利用1960—2024年呼伦贝尔市16个国家气象站日最低气温数据,综合气候统计方法、Mann-Kendall检验及Morlet小波分析,系统研究了极寒天气的时空分布、变化特征及其突变与周期性规律。结果表明:(1)呼伦贝尔市极寒日数空间分布极不均匀,主要集中在北部大兴安岭地区,由北部向西南、东南递减明显,北部图里河年均极寒日数最多(17.20 d),东南部的扎兰屯、阿荣旗、博克图3站未出现极寒天气；极寒天气频次在1月最多(占47.8%),11月最少(占0.8%)；极寒日数年际变化呈显著递减趋势,倾向率为-2.23 d?(10 a)-1 ,1971年突变后极寒日数显著减少；极寒日数在研究期内存在12～15 a周期性特征,1990年之前和2000年之后较明显,1990—2000年周期变化稍有减弱,其中1960—1970年还存在6～7 a周期性特征。(2)全市年极端最低气温69%出现在图里河,22%出现在根河,65年平均极端最低气温-45.3 ℃,极值出现在1966年2月22日图里河站(-50.2 ℃),58.5%出现在1月；年际变化呈上升趋势,倾向率为0.21 ℃?(10 a)-1,1971年突变后极端最低气温显著上升,但2016年之后增暖趋势放缓；年极端最低气温周期性变化特征不明显。(3)极寒天气影响范围和持续时间均呈递减趋势,其倾向率分别为-1.5 d?(10 a)-1 、-0.6 d?(10 a)-1,最长连续极寒日数达28天,发生在1976年12月19日至1977年1月15日。研究表明,呼伦贝尔市极寒天气受全球变暖影响显著,但近年极寒天气仍频发,需加强监测预警,为区域防灾减灾及冷资源利用提供科学支撑。

Abstract:

In this study,the spatial-temporal distributionin,variation rate,abrupt changes and periodic patterns of extreme cold weather in Hulunbuir were analyzed based on daily minimum temperature data from 16 national meteorological stations in Hulunbuir during 1960-2024,by means of integrated climate statistical methods,Mann-Kendall tests,and Morlet wavelet method.The results indicate that:(1)The spatial distribution of extreme cold days is highly uneven,mainly concentrated in the northern Greater Hinggan Mountains region, with a significant decrease from north to southwest and southeast.The annual average days of extreme cold weather is highest in Tulihe station (17.20 d), while no extreme cold weather occurred in the southeast stations such as Zhalantun, Arongqi, and Boketu.The frequency of extreme cold weather is highest in January (47.8%) and lowest in November (0.8%). The interannual variation of extreme cold weather shows a significant decreasing trend as -2.23 d?(10 a)-1. After the abrupt change in 1971, the average days of extreme cold weather significantly decreased..During the study period, there is a 12-15 year periodicity of extreme cold days,which is more pronounced before 1990 and after 2000, with a slight weakening of the periodic variation between 1990 and 2000.Additionally, a 6-7 year periodicity exists from 1960 to 1970.(2) The average extreme minimum temperature over 65 years is -45.3°C, with the lowest temperature recorded on February 22, 1966, at Tulihe station (-50.2°C),where 69% of extreme cold weather occurred, other 22% occurred at Genhe station.In addition,58.5% of extreme cold weather occurred in January.The interannual variation shows an upward trend at the rate of 0.21°C?(10 a)-1. After the abrupt change in 1971, the extreme minimum temperature significantly rose, but the warming trend slowed down after 2016. The cyclical variation characteristics of the annual extreme minimum temperature are not obvious. (3) The impact area and duration of extreme cold weather both show a decreasing trend, with trend rates of -1.5 d?(10 a)-1 and -0.6 d?(10 a)-1, respectively. The longest duration of extreme cold weather reached 28 days, occurring from December 19, 1976, to January 15, 1977. The study indicates that extreme cold weather in Hulunbuir is significantly affected by global warming, but still occurs frequently in recent years. It is necessary to strengthen monitoring and early warning to provide scientific support for regional disaster prevention and mitigation and the utilization of cold resources.