磁暴不同相位期间低纬海南地区电离层扩展F分布特性研究

The Features of Ionospheric Spread-F during the Different Phases of Magnetic Storms in Low Latitude Hainan Region

基于2002—2007年海南地区DPS—4测高仪探测数据,对海南地区电离层四种类型扩展F,包括频率型(FSF)、区域型(RSF)、混合型(MSF)和强区域型(SSF),在磁暴不同相位期间的年际变化和总体分布特性进行了统计分析研究。结果表明:(1)在初相期间,较为活跃的扩展F是在高年(2002)和下降年(2003—2004)的SSF,以及低年(2005—2007)的MSF;(2)在主相期间,较为活跃的扩展F是2002、2006年的SSF和2005、2007年的MSF;(3)在恢复相期间,较为活跃的扩展F是2002年的SSF和2003—2006年的MSF,并且MSF的发生率随太阳活动减弱(从2002年到2006年)有增加趋势。总体上,最为活跃的是SSF和MSF,其次是FSF,而最不活跃的是RSF。分析还表明,初相期间扩展F的发生率要高于主相和恢复相的发生率,这说明快速渗透电场对初相期间的扩展F有促进作用;而主相和恢复相期间扩展F的发生率则受到了快速渗透电场、扰动电场等因素的共同作用。

Based on the data observed by DPS--4 at Hainan station during 2002--2007, the annual and total distribution features of SF, which includes Frequency SF （FSF）, Range SF （RSF）, Mixed SF （MSF）, and Strong range SF （ SSF）, in the different phases of magnetic storms are statistically analyzed. The results are shown ： （1） in initial phase, the more active SF is SSF during the high （2002） and middle solar active years （2003-- 2004 ） and MSF during the low solar active years （2005--2007）. （2） In main phase, the more active SF is SSF in 2002 and 2006, and MSF in 2005 and 2007. （3） In recovery phase, the more active SF is SSF in 2002 and MSF in 2003--2006. Moreover, the occurrence rate of MSF increased as the solar activity decreased from 2002 to 2006. Totally, SSF and MSF are the most active, then FSF is less active, and RSF is least active among the different storm phases. Furthermore, the fact that the occurrence rate of SF is higher in the initial phase than in the main and recovery phases is due to Prompt Penetration Electric Field （PPEF） which is inclined to trigger SF in the initial phase, but the occurrence rates of SF during the main and recovery phases are primarily caused by the interaction