天山西部地区冰雹云的卫星光谱特征及监测应用

Satellite Spectrum Characteristics of Hail Cloud over Western Tianshan Mountains and Monitor Application

针对冰雹灾害多发的新疆天山西部地区,利用2007年和2008年5—10月14次MODIS卫星过境资料,选取共计45个云系样本数,进行冰雹云、强对流云团和薄卷云的光谱特征提取和雹暴指数计算与分析。结果表明,冰雹云的热红外亮度温度(CH31、CH32、CH35)均<240K,中红外波段反射率(CH20)相对较低<30%,可见光和短红外波段反射率(CH1和CH6)均>80%,雹暴指数≥0.35,得到了有利于冰雹云的卫星遥感客观判识指标。

Making use of 45 cloud system cases selected from MODIS satellite data during May- December of 2007 and 2008 over the Western Tianshan Mountain areas, where the hail disaster happened frequently, the spectral characteristics and the hail storms indices of the hail clouds, strong convective clouds and thin cirrus are analyzed. The results indicate that the thermal infrared brightness temperature of hail cloud （CH31, CH32, CH35） are all less than 240K, the reflectance of mid-infrared wave band （CH20） is relatively low 〈 30%, the reflection index of visible light and short infrared wave band （CH1, CH6）〉80%, hail storms index≥0.35, which displays the hail cloud objective identification index by satellite remote sensing.