摘要
利用NCEP 1°×1°再分析资料,应用能量天气学方法对发生在2015年8月14日的川西平原暖区暴雨进行了分析。结果表明,总能量在8月14日经历了在上午积聚和午后释放的过程,并且随着时间由北向南增加,这和雨带从成都往眉山、乐山移动一致。总能量极大值14时出现在30°N附近,这和强降雨中心午间出现在眉山吻合。14日白天潜热能和总能量变化趋势一致,且不同时段变化值接近,潜热能的变化是导致总能量变化的主要因子,潜热能是此次川西平原暖区暴雨的主要贡献者。川西平原潜热能明显增大,有利于出现降水,潜在不稳定区和雨区有较好的对应关系。饱和能差较小,对流不稳定能量增加,有利于出现降水。14日14时对流不稳定能量和潜在不稳定能量显著增大,能量平衡高度达到200h Pa附近,导致成片暴雨区的出现。
By using 1°×1°NCEP reanalysis data, an analysis have been performed, with energetics method, to study a heavy rainfall in warm region occurred on 14th August 2015 in westerm plain of Sichuan. The results show that the total energy accumulated in the morning and released in the afternoon. The total energy increased over time from north to south, in keeping with rainfall area moving from chengdu to Meishan and Leshan. The maximum of total energy appeared at two in the afternoon in area near by 30°N, in accordance with heavy rainfall appeared in Meishan at the same time. Because the latent heat energy had the same change trend with total energy on 14th day, and its change value was close to that of total energy at different times, the change of latent heat energy was the main factor which led to the change of total energy. The latent heat energy was the main contributor of this heavy rainfall in westerm plain of Sichuan. The latent heat energy increased apparently, which was advantagous to precipitation. There was a good relationship with latent instability area and rainfall area. The saturation energy difference was small and convective instability energy increased, which was beneficial to precipitation. The convective instabili-ty energy and latent instability energy increased significantly, and energy balance height reached near by 200hPa, which caused large areas of heavy rainfall.
出处
《高原山地气象研究》
2017年第1期14-18,32,共6页
Plateau and Mountain Meteorology Research
关键词
暖区暴雨
总能量
总温度
潜热能
heavy rainfall in warm region, total energy, total temperature, latent heat energy
