Statistical Study Of Ionosphere Mid/Low-latitude Anomalous Anomalous Disturbances

Ionospheric abnormal disturbance is of great significance to identify theionospheric seismic precursor information and short-wave communication. This papermainly work is statistical analysis of Chongqing station Q-disturbance and theestablishment of a strong magnetic storm model of middle and low latitude ionosphere,and on this basis, the difference with pre-earthquake ionospheric disturbances wasdiscussed briefly. Using historical ionospheric data, reliability of the inter quartilemethod has been checked for determining the normal situation of the ionosphericparameters that is adopted as basic value to calculate the ionospheric peterbation. Themain results obtained are as follows:The ionospheric Q-disturbances were statistical studied. By using Chongqingstation foF2historical data for the first time to study the ionospheric Q-disturbances,and analyze the characteristics of the ionospheric Q-disturbances with local time andseasonal variations. Positive disturbance with the local time has a “time forbidden”effect, however, negative disturbance during the day than night time more likely tooccur. Positive disturbance presents a clear semiannual variation, while the negativedisturbance with anniversary changes.The ionospheric storms at middle and low latitudes were statistical analysised. Theionosphere storms with solar activity, latitude, season, local time and the main phase forstorms delay time parameter were analysised by using nine ionospheric stations foF2historical data The higher of solar activity, ionospheric storms the more likely to occur.The negative disturbances are more likely to occur in summer, and positive disturbanceslikely to occur in winter, while with the obvious difference of latitude in spring andautumn. The start time of the positive storms is primarily in day time, while the negativeprimarily in the20-09LT. The storms MPO in what period of time, but rarely negativeionospheric storm start in the10-16LT period.Besides, based on some previous researches, the ionospheric Q-disturbance andmagnetic storms examples are analysised briefly, and study of the distribution of thedisturbance space and the disturbance occurred on time scales, the paper try to find outthe earthquake ionospheric precursor information.