Research On Geomagnetically Induced Currents Events Of Guangdong Based On The Observation Data Of Space Weather

In recent years,geomagnetically induced currents(GIC)is not only limited to high latitude areas,but also can be monitored in mid and low latitudes regions.In order to find the influence of geomagnetic induced current to our country,we studied several geomagnetically induced currents events occurred in Guangdong during 2004 to 2006,using some available observation data of space weather(solar wind data,interplanetary data and geomagnetic data).Because the intense storms(Dst?-100 nT)seemed more probably to raise a GIC event,so we gave a statistical analysis to the intense storms occurred in the declining phase of solar cycle 23(2003-2006),and found that although geomagnetically induced currents did not necessarily increasing with the intensity of storms,but the strength of GIC causing by a extreme magnetic storms(Dst?-200 nT)was greater than a common intense storm.While analyzing the influence of interplanetary sources on GIC events,we found that interplanetary coronal mass ejection(ICME)seemed to be the dominant driving source of strong magnetic storms and GIC events in this period.In all kinds of ICMEs,the GIC driven by an ICME that did not follow the MC criteria(nonMC)is weaker than others.Studying on the relationship between the interplanetary parameters and GIC,we found that there was no obvious direct relationship between them.But high solar wind speed and low proton temperature are the characteristics of the magnetic cloud,and we had known that among the all interplanetary structures,the magnetic cloud was more probably to drive a high intensity GIC event.In addition,the long time deflection of the of interplanetary magnetic field component in Z direction B,was more likely to cause strong magnetic storms and GIC events.If we want to simulate the geomagnetically induced currents based on the solar wind and interplanetary data,we must establish a model to describe the effect of solar wind on the earth's magnetic field first.Based on the theory of three-dimensional magnetohydrodynamics(MHD),the scientists had developed many different models which can be used in the prediction of geomagnetic storms and GIC events combined with the knowledge of power.In this paper,we used solar wind and interplanetary parameters to simulate the Dst of two examples based on Burton equations to test its suitability for geomagnetic storm prediction.Only by mastering the method of magnetic storm prediction,can we further study the prediction of GIC events.