【摘要】 利用内蒙古自治区107个国家气象站1961—2016年冬半年逐日降雪资料,采用相对极值处理方法确定了各站极端降雪事件的阈值,详细分析了内蒙古地区极端降雪事件的时空分布特征。研究结果显示:内蒙古中东部地区有3个极端降雪事件频发区域;阈值、极值、频率和极端降雪强度有明显的空间分布特征和差异;从发生站次数的年代际变化情况看,20世纪70年代是频发期,其次是60年代和21世纪以来的前10a,20世纪90年代以来有增多的变化趋势;在月际循环上,极端降雪事件表现为双峰的特征,最大值位于3月,次大值位于11月。区域分布特征也有明显的差异,112°E以东表现为双峰型特征,以西是单峰型特征;21世纪以来达到或超过历史极值的极端降雪事件发生频繁,地域分布特征和极端性突出。更多还原

【Abstract】 Basing the data of daily precipitation of 107 weather stations in winter-half-year from 1961 to 2016, the threshold of extreme snowfall was calculated using relative extreme method, and the temporal and spatial distribution characteristics of extreme snow events in Inner Mongolia were analyzed in detail. It shows that there were three major prone areas in mid-east Inner Mongolia. There were obvious spatial distribution characteristics and differences in threshold, extreme values, frequency and strength. The frequency of extreme snowfall has significant inter-decadal and monthly variations. On the decadal scale, the frequent occurrence period was 1970 s, followed by 1960 s and the first 10 years since the beginning of this century. Since 1990 s, there has been a trend of increasing. Extreme snow events showed a characteristic of double-peaked, and the maximum value was in March, the second maximum value was in November. Regional distribution differences of the extreme snow events were also obvious. The eastern region of 112°E was characterized by double-peaked type, and the western region of that was single-peaked. Extreme snow events that have reached or exceeded historical extremes have occurred frequently since the beginning of this century, and the regional distribution characteristics and extreme were prominent.更多还原