Analysis Of Geomagnetic And Ionospheric Scintillations Over Guangzhou Region And Study The Anomaly Of TEC During The Earthquake

Firstly, this paper introduces the background and theory of geomagnetic field,ionospheric scintillation total electron content (TEC) and solar activity, as well as thecurrent situation and development of ionosphere and its disturbances during anearthquake period. Then, the geomagnetic data recorded in Zhaoqing geomagneticstation, scintillation data observed by ionospheric scintillation monitoring systemlocated in Guangzhou station and TEC map data provided by the international GPSService Center (IGS) are also introduced. Three parts achievements of research areshowed as follow based on utilizing the data of geomagnetic, ionospheric scintillationand TEC.1）By analyzing the relationship between the disturbance amplitude of a singlegeomagnetic station’s data and the geomagnetic planet indices of Ap and Kp for along time. Using the geomagnetic minutes data of H component from January2003toJuly2010of Zhaoqing station to estimate the planetary indices of Ap and Kp, andcomparing with the Ap and Kp indices from the Word Data Center. Results show that,in accordance with the above method using tne Zhaoqing geomagnetic data toestimate Ap and Kp indices is feasible in a certain error range. Although theestimating effect of the method have a slightly downward trend in the strong magneticdisturbance time.2）The correlations between geomagnetic disturbance and GPS ionosphericscintillations are studied here using geomagnetic monitoring data of Zhaoqinggeomagnetic station and the ionospheric scintillations observed by GPS monitoringnetwork of South China,which is established by Guangzhou meteorological satelliteground stations. With the use of Geomagnetic K values converted from the variationof geomagnetic horizontal component H at Zhaoqing to represent geomagneticdisturbance over Guangzhou region, we statistically analysis the relationshipsbetween the geomagnetic disturbance and amplitude scintillation index (S4) overGuangzhou region during solar minimum. Analysis indicates that most stroms/strongmagnetic disturbance of the year did not trigger the scintillation occurrence, and thatthe ionosphere scintillation occurrence is mainly confined to the periods of lower Kvalues, and that the ionosphere scintillation occurrence declined for periods of higherK values(K>=4). Occurrence rate of ionosphere scintillations is changed with seasonsand the geomagnetic activities. The scintillations occurrence rate is obvious correlation with the variation of geomagnetic activity K index, i.e., as the index Krised, occurrence rate of scintillations of medium above in night, weak in spring, andmedium in summer decreases. But there is no obvious relationship betweenoccurrence rate of ionosphere scintillation and K values in autumn and winter. Inaddition, comprehensive analyses the effects of geomagnetic and solar activity onionosphere activity shows that there are more ionosphere scintillations overGuangzhou region during geomagnetic quiet and low solar activity periods.3）Analysis the ionospheric anomalies observed during the strong earthquake(M=7.2) which occurred in Burma (20.8°N,99.8°W) during March2011. As a result,we found that the anomalous TEC disturbances over the zone of Burma earthquake,which took place ten days before the events: at the beginning, the TEC of equatorialionization anomaly (EIA) north crest was decreasing during16-18March, and theNorth crest moved toward equator at18March, and the anomalous of the TECdisappeared completely step by step. The geomagnetic situations were rather quiet onthe days during the earthquakes, and solar activity was in a relatively stablemiddle-low level. We can conclude that the observed anomalous of the ionosphericTEC was likely associated with the imminent earthquake.