Abstract: By using of echo data of new generation weather radar, radar station upwind meteorological radiosonde data and the track of seeding catalyst by aircraft in Dec.26 of 2007, early catalytic effect assessment for Xinjiang winter sheet clouds, the author designs a new test mode to carry out a quantitative calculation. The specific mothods are showed as follows: (1) A track of seeding catalyst by aircraft is intercepted out of a radar echo (PPI). (2) A banding track with 10 km width is set as a “seeding area” which represents the evolution of a being seeded cloud; The windward area with 10 km width is set as a “contrast district A”, which represents the evolution of a natural state cloud; then the downwind area with 10 km width as a “contrast district B”, the evolution of a cloud under deffusion state. (3) The gross radar echo intensity(dbz) in these 3 regions is calculated respectively; with the continuing radar observation, 3 curves of radar echo intensity changing with time are obtained. (4) By contrasting the trend of these 3 curves, the preliminary conclusion is showed as the follow: After the seeding cloud by aircraft, the gross radar echo intensity(dbz) either in “seeding area” and “contrast district B” gets a clearly increasing trend contrasting with the condition in “contrast district A”.

Key words: aero snow enhancement, radar echo intensity (dbz), location seeding, catalyst effect