摘要
雷暴结构的探测是当今的热点问题。雷暴底层的细结构探测尚未见报道。本文利用一幅ERS-1图像,探测雷暴底层在海面留下的痕迹,结合辅助NOAA AVHRR和NCEP数据分析了2002年8月11日发生在台湾海峡的一次中尺度雷暴过程。结果表明,此次雷暴过程是在锋面前沿产生的,北风和南风切变为此次过程提供了激发动力。雷暴呈现椭圆形结构,长短半轴分别为13 km和10km,风暴中心强降雨区直径达5 km,雷暴前进方向是东北向,移动速度为5.9 m/s,在雷暴后部存在有组织的尾状条纹,结合雷暴结构诊断分析认为此尾迹是龙卷中心拖曳留下的痕迹。在雷暴外流区,冷空气反气旋式下降,周围的暖空气气旋式上升,两股气流的风切变导致大气内波的产生。此内波含有12个孤立子波,波长从450 m到237.5 m,平均波长为297.9 m。
Thunderstorms structure detection is a hot issue. Fine structure of the bottom of the thunderstorm has not yet been reported. An ERS-1 image was used to detect the bottom structure of a thunderstorm developed on 11 August 2002 in the Taiwan Strait. The meso-scale thunderstorm process is discussed with simultaneous NCEP and NOAA AVHRR data. The results show that this process of thunderstorm is developed in the forefront of the front. The southerly and northerly wind shear provides the impetus for this process. The thunderstorm shows oval structure with semi-axis respectively 13km and 10km. The heavy rains core in the center of the storm area reaches 5 km in diameter. The thunderstorm travels to the Northeast with a speed of 5.9m/s. There is a long organized caudate stripe in the rear of the thunderstorm. The thunderstorm structure diagnosis analysis suggested that this stripe is a foot mark from the tornado associated with the thunderstorm. It＇s very interesting that there are atmospheric gravity waves trapped in the thunderstorm. The mechanism analysis supported that in the outflow region, the anti-cyclonic cold air falls down and encounters the cyclonic up warm air around. These two different streams leaded to the atmospheric wind shear and thus caused the wave generation. The wave contained at least 12 solitary waves, the wavelength were from 450 meters to 237.5 meters with an average value of 297.9 meters.
出处
《遥感技术与应用》
CSCD
2007年第2期246-250,共5页
Remote Sensing Technology and Application
基金
国家863项目(2002AA633120)支持
关键词
合成孔径雷达
中尺度雷暴
大气内波
SAR, Mesoscale thunderstorm, Atmospheric gravity waves
