摘要
利用1988～1999年欧洲非相干散射EISCAT(EuropeanIncoherentScatter)雷达观测数据,对不同太阳活动周相、不同季节的极光椭圆区电离层F区电子密度进行统计分析,研究其气候学特征,并与IRI 2 0 0 1模式比较.EISCAT观测到的电子密度显示出显著的太阳活动高年“冬季异常”和太阳活动低年半年变化等现象.EISCAT实测电子密度随时间和高度的平均二维分布和5 0 0km高度以下总电子含量TEC ,从总体来看与IRI 2 0 0 1模式预测结果符合较好.但高年在TEC达到最大值前后,IRI 2 0 0 1模式预测的电子密度高度剖面与EISCAT观测结果有显著差别:F2 峰以上IRI 2 0 0 1模式预测的电子密度过大,造成TEC明显高于雷达观测值.另外,在太阳活动下降相,EISCAT观测显示出明显的半年周期季节变化特征,但IRI 2 0 0
With EISCAT (European Incoherent Scatter) radar observations during 1988～1999, the climatologic features of electron densities in the auroral ionospheric F-region have been investigated statistically and compared with the IRI-2001 model for different seasons at different phases of the solar cycle. The electron densities from EISCAT observations show obviously the well-known winter anomaly in solar maximum and a semiannual variation in solar minimum. The averaged 2-D distributions of EISCAT N_e versus t_ UT and height H, as well as diurnal variations of TEC up to 500 km, are reasonably consistent with those predicted by the IRI-2001 model as a whole. The height profiles of N_e, however, are remarkably different between the IRI model and the EISCAT observations around the time when the TEC reaches its maximum. In this case the electron density above F_2 peak is too large in the IRI-2001 model, causing higher TEC than EISCAT observations. On the other hand, EISCAT observations show obviously characteristics of a semiannual variation at the fall phase of solar activity, however, the results of IRI-2001 model show no evidence of that.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第3期471-479,共9页
Chinese Journal of Geophysics
基金
国家重点基础研究发展规划 973项目 (G2 0 0 0 0 7840 7)资助
关键词
极区电离层
气候学特征
冬季异常
电离层模式
Polar ionosphere, Climatologic characteristics, Winter anomaly, Ionospheric model
