关键词: Spread-F, 地理三维Spread-F模型, Spread-F的全球特征

Abstract: A new model was presented in a three dimensional geographic coodinate system to describe the linear growth of R-T instability so that the effects of magnetic inclination and declination were taken into accont. It is an generalization of former theories from equatorial to mid-latitude regions. From this model one can see the influence of magnetic strength, inclination and declination. Due to the magnetic effects, the occurrence rate of the instability is not symmetric in longitudes even at the magnetic equator. Some occurrence peaks or valleys will appear in certain places around the world.

Key words: Spread-F, geographic three-dimensional model, global characteristics