Abstract: To approach the relationships between grasshopper occurrence and atmospheric circulation characteristics is the foundation for establishing synoptic forecast models of grasshopper disaster. By using the principles of statistics, this paper analyzed the relationships between grasshopper occurrences in Inner Mongolia and atmospheric circulation characteristics. The results showed that the southward shift of subtropical anticyclone ridge over the West Pacific in last July was advantageous to the growth and oviposition of grasshopper imagoes, while the northward shift of the north boundary of North America subtropical anticyclone in North Africa Atlantic in February and the stronger polar vortex intensity indices in Pacific Ocean in January had negative effects on the egg mass of grasshopper in winter and its growth in summer. The grasshopper disaster grades were above the third grade when the center of the polar vortex in the Northern Hemisphere in May was located nearby 60°-90°W.

Key words: N₂O emission, Cropping system, Paddy soil, Water regime