Air Crash Case Study: Icing Event over the Taiwan Strait

Various meteorological data charts derived from in situ observations, satellite imagery, soundings near an air crash site and the Tropical Rainfall Measuring Mission Microwave Imager (TMI) level 2A hydrometeor profile product were used to investigate the synoptic and mesoscale environment of an icing event (IE) over the Taiwan Strait on 20 December 2002. The IE occurred in a frontal cloud system. A series of meteorological chart analyses shows that the relative humidity at the 850 and 700 hPa levels reached 80% and 90%, respectively. In addition, there was an occurrence of small-scale negative vorticity (shear vorticity). The sounding observations revealed widespread light to moderate icing over the crash site. The TMI level 2A hydrometeor profile product provided further evidence of the existence of icing. The intensity of the icing was 0.3 gm -3 , the vertical thickness reached 4 km, and the icing duration exceeded 24 h.