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Two-dimensional observations of midlatitude sporadicEirregularities with a dense GPS array in Japan
| Title: | Two-dimensional observations of midlatitude sporadicEirregularities with a dense GPS array in Japan |
| Authors: | Maeda, Jun1 Browse this author →ORCID | | Heki, Kosuke2 Browse this author →KAKEN DB |
| Authors(alt): | 前田, 隼1 | | 日置, 幸介2 |
| Keywords: | sporadic E | | ionosphere | | GPS | | GEONET | | TEC |
| Issue Date: | Jan-2014 |
| Publisher: | American Geophysical Union |
| Journal Title: | Radio Science |
| Volume: | 49 |
| Issue: | 1 |
| Start Page: | 28 |
| End Page: | 35 |
| Publisher DOI: | 10.1002/2013RS005295 |
| Abstract: | [1] We observed two-dimensional structure and time evolution of ionospheric irregularities caused by midlatitude sporadic E (Es) over Japan as positive anomalies of total electron content (TEC) by analyzing the data from the nationwide Global Positioning System (GPS) array. In this paper we report a case study of strong Es observed in the local evening of 21 May 2010, over Tokyo, Japan. In the slant TEC time series, Es showed a characteristic pulse-like enhancement of ~1.5 TEC units lasting for ~10 min. We plotted these positive TEC anomalies on the subionospheric points of station-satellite pairs to study the horizontal structure of the Es irregularity. We confirmed that the irregularity existed at the height of ~106 km by comparing the data of multiple GPS satellites, which is consistent with the local ionosonde observations. The horizontal shapes of the Es irregularity showed frontal structures elongated in E-W, spanning ~150 km in length and ~30 km in width, composed of small patches. The frontal structure appears to consist of at least two parts propagating in different directions: one moved eastward by ~60 m s−1, and the other moved southwestward by ~80 m s−1. Similar TEC signatures of Es were detected by other GPS satellites, except one satellite that had line of sight in the N-S direction which dips by 40–50° toward north, which indicates the direction of plasma transportation responsible for the Es formation. We also present a few additional observation results of strong Es irregularities. |
| Rights: | Copyright 2014 American Geophysical Union. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/57020 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 日置 幸介
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