Solar corona study is an important aspect of space weather research.In recent years,great achievements have been acquired on the solar corona study by the space physics group of China.This paper gives a brief outline of these progresses that have been made during 2006—2008.This kind of research includes observational study of the corona,theoretical investigations,statistical analysis based on a large number of data sets,numerical method for MHD modeling,numerical study of space weather events,and prediction methods for the complicated processes originating from the solar corona.Each is given as a separate part in the following.
The temperature curve in the solar chromosphere has puzzled astronomers for a long time. Referring to the structure of supergranular cells, we propose an inductive heating model. It mainly includes the following three steps. （1） A small-scale dynamo exists in the supergranulation and produces alternating small-scale magnetic fluxes; （2） The supergranular flow distributes these small-scale fluxes according to a regular pattern; （3） A skin effect occurs in the alternating and regularly-distributed magnetic fields. The induced current is concentrated near the transition region and heats it by resistive dissipation.
Using 86 CME-interplanetary shock events,the correlation between the peak values of (a) the solar wind parameters(B_z,E_y,P_(dyn)) and the geomagnetic indices(SYM-H,ASY-H,Kp), (b) the coupling functions(Borovsky,Akasofu,Newell) and the geomagnetic indices,(c) the solar wind parameters/coupling functions/geomagnetic indices and the ionospheric parameter(Δf_0F_(2min)), are investigated.The statistical results show that in group(a),B_(z min) and SYM-H_(min) have the best correlation,that in group(b),the best correlation is between the peak values of Akasofu function (A_(min)) and SYM-H_(min),and that in group(c),the best correlation is between K_(pmax) andΔf_0F_(2min). Based on the statistical results,a method for predicting f_0F_2 of a single station is attempted to be set up.The input is modified B_(z min) and the outputs are SYM-H_(min) andΔf_0F_(2min).Then 25 CME-IPS events that caused geomagnetic storms in 1998 and 2009 are used to check the prediction method. The results show that our method can be used to predict SYM-H_(min) andΔf_0F_(2min).
LI ZhengWEI FengsiFENG XueshangGUO JianpengXU Xiaojun
Interplanetary physics study is an important ingredient in space weather research.Considerable progress this aspect has been achieved by the space physics community of China in recent years.This brief report summarizes the latest advances of the interplanetary physics research in China during the period of 2008-2010.This report includes solar corona and solar wind,interplanetary transients,energetic particles,MHD simulation,space plasma,and prediction methods for physical phenomena originating from both solar corona and interplanetary space.
