【摘要】 利用中国科学院大气物理研究所发展的完全弹性三维积云模式,对相似天气背景下黄河上游及渭北地区的强对流云的宏微观特征进行了数值模拟对比研究,并与相应的雷达回波及地面观测资料做了比较分析。模拟结果表明,模式对黄河上游玛曲和渭北地区旬邑的强对流云结构和降水均有很好的模拟能力。与旬邑相比,玛曲零度层低,云底温度低、比湿小,为冷云过程。云中雨水含水量极低,冰晶出现早,维持时间长。云中上升气流弱,对流云发展浅薄。地面降雨量相对较小,固态降水所占比例大,霰为主。霰胚对冰晶的碰并增长是地面软雹的主要来源。旬邑冰雹主要来源是霰,但冻滴也占了一定比例。霰融化是玛曲雨水的最重要来源。而冻滴融化对旬邑雨水的贡献最大。更多还原

【Abstract】 A 3-D convective cloud model with fully elastic was applied to simulate the characteristics of convective cloud in Maqu area of the upper reaches of the Yellow River and Xunyi of Weibei area. Results show that the model have ability to simulate convective cloud structure and rainfall in Maqu and Xunyi. Comparing with Xunyi, the 0℃ level and temperature of cloud bottom was lower and the specific humidity is small in Maqu area. The mainly process of convective cloud is cold. The rain water content is extremely low in cloud. Ice crystal occurs earlier and maintained longer. The up-draft airflow is weaker and cloud develops shallowly. The precipitation is less and most of which are graupel and frozen droplets. The main source of ground soft hail is from the colliding and combining growth of the embryo of graupel to ice crystal. In Xunyi, the main source of hail is graupel but the freezing drip have a fairly ratio. The most important source of rainfall is melting process of graupel for Maqu and freezing droplets for Xunyi.更多还原