摘要
全球电离层分布特别是f_0F_2和h_mF_2对雷达探测、无线电通信以及卫星导航等有非常大的影响,为研究全球f_0F_2和h_mF_2的时空分布,利用全球导航卫星定位系统(GNSS)掩星数据统计分析了全球f_0F_2和h_mF_2的周年变化特性、日变化特性以及季节变化特性,并通过与日本地区测高仪站f_0F_2数据进行对比,分析了两种探测方式获取电离层参数的相关性。结果表明,全球f_0F_2和h_mF_2周年变化与太阳活动和地磁活动具有明显的正相关性,f_0F_2和h_mF_2还具有明显的空间分布特性。此外,全球f_0F_2和h_mF_2峰值出现在LT 14:00—16:00期间,且h_mF_2出现明显的日落后赤道电离异常复苏现象。全球f_0F_2具有比较明显的季节变化特性,f_0F_2峰值出现在春秋季中低纬地区,在夏冬季较小,且出现比较明显的冬季异常现象,而h_mF_2季节分布相比f_0F_2并不明显。通过和日本地区Wakkanai、Kokubunji、Yamagawa以及Okinawa测高仪站f_0F_2数据对比,发现两种探测手段获取的电离层参数具有较好的相关性。初步研究表明,全球f_0F_2和h_mF_2分布受到多种因素的影响,其中太阳活动和地磁活动占主要地位,其次是电场、热层风以及高能粒子沉降等。
The ionosphere is an atmospheric region ionized by solar radiation, cosmic rays, and various particle radiations ranging from 60 km to 1000 km above the earth. Numerous free electrons and ions in the ionosphere can interfere with radio signals. Ionospheric parameters,especially F2 layer critical frequency(f0F2) and electron density peak height(hmF2), play an important role in the propagation of HF waves.Therefore, the study of f0F2 and hmF2, especially its global distribution, is important. The overall objective of this paper is to study the annual, diurnal, and seasonal variations of f0F2 and hmF2 in the world on the basis of GNSS occulation datasets and to compare the values f0F2 obtained by GNSS occultation and digisondes from all stations in Japan. COSMIC, GRACE, and CHAMP electron density profile datasets and digisonde datasets in Wakkanai, Kokubunji, Yamagawa, and Okinawa for 2002—2016 are selected as the data sources. The maximum electron density Nm F2 and hmF2 is obtained by using the electron density profile. Compared with ionosonde f0F2 datasets, the latitude and longitude of the selected Nm F2 are within 5 degrees of ionosondes, and the time of the selected Nm F2 is within 15 minutes of ionosondes. Results show that the annual variation of f0F2 and hmF2 has a significant positive correlation with solar activity and geomagnetic activity and significant spatial distribution characteristics. The maximum value of f0F2 distribution on both sides of the magnetic equator is approximately 15 degrees, and the maximum value of hmF2 distribution in the equatorial region and the northern and southern hemisphere peak heights is not symmetrical. In addition, the peak value of f0F2 and hmF2 appears during LT 14:00—16:00, and hmF2 exhibits significant equatorial ionization anomaly recovery after sunset. The f0F2 has obvious seasonal characteristics;the peak value of f0F2 appears in spring and autumn at middle and low latitudes, and is evident in abnormal winter phenomenon. However, the seasonal distribution of hmF
作者
刘祎
孙睿迪
周晨
赵庶凡
张学民
申旭辉
赵正予
LIU Yi;SUN Ruidi;ZHOU Chen;ZHAO Shufan;ZHANG Xuemin;SHEN Xuhui;ZHAO Zhengyu(Department of Space Physics, Electronic Information School, Wuhan University, Wuhan 430072, China;Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China;The Institute of Crustal Dynamics, China Earthquake Administration, Beijing 100085, China)
出处
《遥感学报》
EI
CSCD
北大核心
2018年第S1期81-92,共12页
NATIONAL REMOTE SENSING BULLETIN
基金
国家自然科学基金(编号:41774162
41574146)
中国地震局地震预测研究所基本科研业务费(编号:2015IES010103)~~
