摘要
利用横断山系云岭余脉点苍山东西侧两个国家级气象台站2005-2012年逐小时降水量数据,详细分析东侧和西侧降水特性及差异。结果表明点苍山东西侧多年平均降水气候态相似,两侧年降水量接近,降水季节演变一致,但小时尺度的降水变化却存在明显差异:降水量和降水频次日变化在东侧以单峰型为主,西侧则双峰型变化显著;东西侧均存在后半夜降水量和降水频次高峰,主要由持续6 h及以上的长时降水事件引起,且该高峰对总降水量的贡献东侧略大于西侧、持续时间东侧略长于西侧;西侧在午后至傍晚出现另一个降水量和降水频次高峰,一般由持续6 h以下的中、短时降水事件造成;累积小时降水量和降水频次的最大值东西侧均于凌晨出现,出现时间东侧滞后于西侧3 h;累积小时降水量的最小值东侧出现于傍晚、西侧则在正午发生,而累积小时降水频次的最小值东西侧均出现在正午前后。小时雨强日变化西侧较东侧强烈,尤其是夜间,西侧存在21时和03-04时大雨强时段,东侧雨强则缓慢变化于清晨07-08时达最大。这种小时降水特性的东西差异受点苍山地形影响,南北走向高大山脉的特殊地形使两侧下垫面辐射差异在傍晚达最大,辐射强的西侧容易形成降水量、降水频次、小时雨强的傍晚高峰。该区域降水特性的不均匀分布使其成为西南复杂地形区气候区域差异的典型代表。
Based on the 2005 — 2012 hourly precipitation data from two national meteorological stations on the east and west sides of Diancang Mountain,a part of Hengduan Mountains' ranges,precipitation characteristics on each side and differences between them have been analyzed in detail.The results show that the climate states of average precipitation,annual precipitation and seasonal evolution on both sides are similar,but there are visible differences of the diurnal variations of precipitation between the east and west sides.The diurnal variation of rainfall amount and rainfall frequency presents a single peak curve on the east side,but significant double peaks are clear on another side.The two sides' rainfall amount and rainfall frequency show peaks in late night which are mainly caused by long-duration rainfall events lasting over6 hours.The peaks of west side's rainfall amount and rainfall frequency appear from afternoon to dusk,which are always derived from the contribution of rainfall events lasting less than 6 hours in duration.The accumulated rainfall amount and rainfall frequency reach the maximum in early morning on each side,but the occurrence time on the east side lags behind about 3 hours to the west side.The minimum of the accumulated rainfall amount at dusk on the east side appears,but on the west side it always occurs at noon while the minimum of the accumulated rainfall frequency on each side happens at around noon.The diurnal variation of hourly rain intensity on the west side is bigger than the west side,especially at night.The hourly rain on the west has two intensive periods(21:00 and 03:00-04:00),but it has slow diurnal variation on the east,getting to the maximum from 07:00 to 08:00.The difference of hourly precipitation between two sides is undoubtedly affected by the geography of Diancang Mountain.Due to the topography,the difference of the surface radiation on the east and west sides reaches the maximum at dusk,leading to a peak about rainfall amount and rainfall frequency,and hourly rain inte
出处
《气象》
CSCD
北大核心
2015年第1期17-24,共8页
Meteorological Monthly
基金
国家自然科学基金项目(41322034)
公益性行业(气象)科研专项(GYHY201406001)
中国气象科学研究院基本科研业务费项目(2013Z004)共同资助
关键词
点苍山
日变化
降水量
降水频次
小时雨强
降水事件
东侧
西侧
Diancang Mountain
diurnal variation
rainfall amount
rainfall frequency
hourly rain intensity
rainfall event
the east side
the west side
