全国低风速气象特征分析
Characteristics of Low Wind-Speed Meteorology in China

摘要 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。
Abstract 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.