Effects of Enhanced Auroral Disturbance on Mid-and Low Latitude Ionosphere

The behaviour of f₀F₂ from five stations located at mid-and low latitudes around 120°E during enhanced auroral disturbances is examined in this paper.The data used are classified into two groups,one is for the years of 1966 to 1970 under the conditions of AE larger than 1400,the others is from 1969 for AE larger than 1000.The results show some features different from those obtained on the chain of Indian stations for AE>1000.Instead of an increase,f₀F₂ on 120°E stations decreased in general to some extent,f₀F₂ of Manzhouli,being at higher latitude,decreased more markedly than that of lower latitude station like Beijing.In addition,this study also showed different behaviours of the after-effect of auroral disturbances for stations of different latitudes.The f₀F₂ at low latitude stations such as Wuchang,Guangzhou and Hainan exhibits an increase in the morning immediatly after the disturbance,meanahile,Manzhouli’s f₀F₂ is still decreasing.It is considered that at low latitude zone the f₀F₂ is affected mainly by changes of the equatorial fountain effect.At mid-latitude zone,however,it is influenced mainly by a global disturbed electric field during enhanced auroral disturbances,this is a manifestation of the latitudinal transfering coupling of electric field.Of course,perturbations of mid-and low latitude neutral atmosphere due to direct energy input into the auroral neutral atmosphere also contribute to the phenomena observed.