1989年3月特强磁暴期间的电离层暴

用欧亚大陆地面电离层垂测站资料考察1989年3月12～16日磁暴期间的电离层暴形态及其发展变化. 特强磁暴引发的电离层暴是全球性的,但自磁层沉降的高能粒子对热层低部的加热程度及区域分布不同,因而各经度链区域内电离层暴的特征也有所差异. 本文研究表明,与理论推断对照,欧洲地区内F2层最大电子密度NmaxF2(或f0F2)并不出现正暴现象,而负暴自高纬向低纬的发展则与典型的热层环流结果相符. 此外,此磁暴过程期间在中低纬区存在明显的波动过程. 在亚洲高纬地区,磁暴初期13日有约10 h的正暴,而负暴过程则与欧洲地区类似,但不太清晰；且无波动现象. 磁暴期间,同一经度链的中低纬地区,夜间常发生多站同时的h′F突增. 本文再次证实这是一般磁暴期间常出现的普遍现象.

An ionospheric storm during the period of a very strong magnetic storm in March 1989

The morphology and its variations of an ionospheric storm related with a very strong magnetic storm on 12th～16th March, 1989 are examined, using the ionosonde data obtained at stations in European and Asian areas. The strong ionospheric disturbances caused by the significant magnetic storm appeared on the whole world. Since the storm heating intensities at the lower thermosphere resulting from energetic particles precipitated from the magnetosphere are different from area to area, the features of the ionospheric storm are also discrepant in different longitudinal chain regions. As compared with deduction from the theory, there was no “positive” storm period of NmaxF2 (or f0F2) in Europe, while the developing tendency of the “negative” storm from high to low latitudes was consistent well with the result deduced from the thermospheric circulation. Moreover, at the mid and low latitude areas there was an evident wavelike process. On the other hand, at the high latitude of the Asian meridian there was a “positive” storm lasted ～10 h on March 13th in the early stage of the magnetic storm. As to the feature of the “negative” storm, it was similar to that in Europe, but not as distinct as there. Besides, there was no wavelike phenomenon at the Asian area. During the magnetic storm in the mid and low latitude areas along a same meridian one can also see the nig httime simultaneous sudden enhancement of h'F. It is proved once more that t his is a universal phenomenon during a magnetic storm.