中国北方沙尘天气的气候条件

On Climate Background of Duststorms over Northern China

利用1954～2000年全国700多个测站的气象资料分析了近50年来我国沙尘暴和扬沙天气的季节变化和年际变化特征,特别着重分析了大风、降水等气象要素对沙尘天气形成的影响.结果表明:我国的沙尘天气受到多种气候要素的综合影响,西北地区和内蒙古西部沙尘多发区的沙尘天气频数受气象条件影响最为显著;风速、湿度在沙尘天气的季节变化中影响最大,降水在沙尘天气的年际变化中影响最大.上一年夏季的降水对春季的沙尘天气具有一定的预报意义.

Based on duststorm observations during 1954-2000 from around 700 meteorological stations, this paper analyzed seasonal and inter-annual variation features. The impacts of strong wind and precipitation on the duststorms were especially emphasized. The results show that the frequency of China's duststorms is influenced by many climate factors. In NW China and northern Inner Mongolia, the main duststorm regions, the influences of climate conditions are most obvious. Wind speed and humidity are the most important controls for the seasonal cycle of duststorm frequency, and precipitation is one of the most dominant factors impacting inter-annual variability. The good correlation between the summer rainfall and duststorm frequency of next spring suggests some climate predictability.