全国低风速气象特征分析

利用1985-2014年NCDC数据库345个地面站的气象资料, 统计全国低风速条件的日变化、月际变化、年际变化和持续性等基本特征, 分析低风速频率空间分布的规律和季节变化。选取哈尔滨、乌鲁木齐、北京和成都4 个代表城市, 分析不同地区低风速条件的特征和年际变化情况。结果表明: 1) 30年间, 全国低风速频率约为40%, 其中哈尔滨低至25%, 成都高达60%; 2) 低风速出现频率表现为夜间高、白天低的特征; 3) 全国从9月至次年1月, 低风速状况出现频繁, 之后不断减少, 春季4月达到最低, 哈尔滨秋季的低风速频率最高, 其他3 个代表城市皆是秋冬季的低风速频率最高; 4) 全国持续3个小时(及以上)的低风速状况出现概率为36%, 其中成都地区的低风速持续性高, 持续12小时(及以上)的概率达到20%; 5) 全国低风速频率的总体空间分布是南方高北方低, 内陆高沿海低, 分布的范围和频率随季节变化; 6) 哈尔滨的低风速频率有明显增加趋势, 其他3个代表城市的长期变化趋势不明显。

Characteristics of Low Wind-Speed Meteorology in China

Based on the surface data of NCDC (National Climatic Data Center), the wind data of 345 stations during 1985 to 2014 are chosen, the characteristics of low wind-speed meteorology and the distribution of low wind-speed’s mean percentage in China are analyzed. Harbin, Urumqi, Beijing and Chengdu are chosen from 345 stations as representative cities, and the characteristics and annual variabilities of low wind-speed’s percentage are studied. The results show that: 1) The probability of occurrence of low wind-speed is about 40% in China during recent 30 years, as for the four representative cities, Harbin is the lowest (25%), Chengdu is the highest (60%); 2) Time-of-day occurrence: during the period of midnight and early morning, the probability of occurrence of low wind-speed is high; 3) Monthly occurrence: from September or October to next year January, the probability of low wind-speed maintains at a high level, the lowest probability happens in April; 4) Persistence, 36% low wind-speed condition can last at least 3 hours in China, in the four cities, 20% low wind-speed conditon can lasts at leat 12 hours in Chengdu; 5) Distribution, the probability of low wind-speed is high in the South and the inland, while it is low in the North and the coastal; 6) Annual variabilities, Harbin has increasing trend, while other three stations’s long-term trend is not obvious.