文章基本信息

标题：The First Report on the Afternoon E -Region Plasma Density Irregularities in Middle Latitude
本地全文：下载
作者：Tae-Yong Yang ; Young-Sil Kwak,† ; Jaewook Lee, 等
期刊名称：Journal of Astronomy and Space Sciences
印刷版ISSN：2093-5587
电子版ISSN：2093-1409
出版年度：2021
卷号：38
期号：2
页码：135-143
DOI：10.5140/JASS.2021.38.2.135
语种：English
出版社：Korean Space Science Society
摘要：We report, for the first time, the afternoon (i.e., from noon to sunset time) observations of the northern mid-latitude E-region field-aligned irregularities (FAIs) made by the very high frequency (VHF) coherent backscatter radar operated continuously since 29 December 2009 at Daejeon (36.18°N, 127.14°E, 26.7°N dip latitude) in South Korea. We present the statistical characteristics of the mid-latitude afternoon E-region FAIs based on the continuous radar observations. Echo signal-to-noise ratio (SNR) of the afternoon E-region FAIs is found to be as high as 35 dB, mostly occurring around 100–135 km altitudes. Most spectral widths of the afternoon echoes are close to zero, indicating that the irregularities during the afternoon time are not related to turbulent plasma motions. The occurrence of afternoon E-regional FAI is observed with significant seasonal variation, with a maximum in summer and a minimum in winter. Furthermore, to investigate the afternoon E-region FAIs- Sporadic E (Es) relationship, the FAIs have also been compared with Es parameters based on observations made from an ionosonde located at Icheon (37.14°N, 127.54°E, 27.7°N dip latitude), which is 100 km north of Daejeon. The virtual height of Es (h’Es) is mainly in the height range of 105 km to 110 km, which is 5 km to 10 km greater than the bottom of the FAI. There is no relationship between the FAI SNR and the highest frequencies (ftEs) (or blanket frequencies (fbEs)). SNR of FAIs, however, is found to be related well with (ftEs–fbEs).
关键词：very high frequency (VHF) coherent backscatter radar ; afternoon E-region irregularities ; mid-latitude