基于卫星红外窗亮温探测上冲云顶

Satellite-based detection of overshooting cloud tops using infrared window channel brightness temperature

上冲云顶是卷云砧上的穹顶状突起,表示存在强对流切变和强烈上升气流,是强雷暴的重要指示者。伴随上冲云顶的雷暴经常产生灾害性天气,如航空湍流、强降雨、冰雹、破坏性的风和龙卷等。本文以2010年9月6日发生在安徽北部地区的一次特大暴雨过程为例,用卫星红外窗区通道观测亮温探测上冲云顶,并将高时空分辨率的局地分析预报系统(LAPS)的中尺度分析场资料与用红外窗方法探测到的上冲云顶进行定性比较,结果表明造成此次强降雨过程的对流系统即为一个伴随上冲云顶的强雷暴系统,LAPS中尺度分析场资料客观地验证了上冲云顶的存在。

An overshooting convective cloud top is a domelike protrusion above a cumulonimbus an- vil and signifies strong troposphere shear and intense updrafts. The deep convective storms with overshoo- ting tops are capable of producing hazardous weather conditions such as aviation turbulence, heavy rain- fall, large hail, damaging wind, tornado and so on. This paper took a heavy rainfall process in the north of Anhui province on 6 Sep 2010 for example. Based of satellite infrared window channel brightness tem- perature, overshooting tops was detected and local analysis prediction system（LAPS） of the high temporal and spatial resolutions was used to compare. The results are shown as follows： the convection system which caused this heavy rainfall process is a strong thunderstorm which accompanies overshooting cloud tops; LAPS mesoscale data proved the presence of the overshooting cloud tops.